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[ { "plaintext": "In telecommunication, automated information systems security comprises measures and controls that ensure confidentiality, integrity, and availability of the information processed and stored by automated information systems. The unauthorized disclosure, modification, or destruction may be accidental or intentional.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 40760, 18985062, 40746 ], "anchor_spans": [ [ 3, 20 ], [ 137, 149 ], [ 157, 168 ], [ 193, 221 ] ] }, { "plaintext": "Automated information systems security includes consideration of all computer hardware and software functions, characteristics and features; operational procedures; accountability procedures; and access controls at the central computer facility, remote computer, and terminal facilities; management constraints; physical structures and devices, such as computers, transmission lines, and power sources; and personnel and communications controls needed to provide an acceptable level of risk for the automated information system and for the data and information contained in the system. Automated information systems security also includes the totality of security safeguards needed to provide an acceptable protection level for an automated information system and for the data handled by an automated information system.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 15036, 21808348, 5309, 40684, 7878457, 249402, 609152, 3270043, 33094374, 40746, 18985040 ], "anchor_spans": [ [ 10, 38 ], [ 69, 86 ], [ 91, 99 ], [ 196, 210 ], [ 227, 235 ], [ 267, 275 ], [ 364, 376 ], [ 388, 393 ], [ 421, 435 ], [ 499, 527 ], [ 540, 544 ] ] }, { "plaintext": "In information security, automated information systems security is a synonym for computer security.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 15036, 7398 ], "anchor_spans": [ [ 3, 23 ], [ 81, 98 ] ] }, { "plaintext": "Federal Standard 1037C", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 37310 ], "anchor_spans": [ [ 0, 22 ] ] } ]

[ "Computer_security_procedures", "Privacy_of_telecommunications" ]

[]

[ { "plaintext": "In telecommunication, an automatic callback is a computer telephony calling feature that permits a user, when encountering a busy condition or other condition where the called individual is unavailable, to instruct the system to retain the called number and to establish the call when there is an available line or when the called number is no longer busy. Automatic callback may be implemented in the terminal, in the telephone exchange, or shared between them. Automatic callback is not the same as camp-on.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 162190, 417914, 2052479, 460792, 26668156, 711372 ], "anchor_spans": [ [ 3, 20 ], [ 49, 67 ], [ 68, 83 ], [ 99, 103 ], [ 402, 410 ], [ 419, 437 ], [ 501, 508 ] ] }, { "plaintext": "Comdial Digitech, DSU, Impact ", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [ 2241700 ], "anchor_spans": [ [ 0, 7 ] ] }, { "plaintext": "Place an intercom call and press CAMP. Your phone will disconnect from the attempted call. When the phone you rang is available, your phone will ring with five ring bursts. Press intercom to ring the other phone. ", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "To use with calls made in the voice-announce mode, press intercom before the camp button.", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "To cancel, press intercom and dial \"#6\".", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Comdial ExecuTech System 2000", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [ 2241700 ], "anchor_spans": [ [ 0, 7 ] ] }, { "plaintext": "Make an intercom call. At the busy signal, dial \"*6\". Hang up. When the desired extension becomes idle, the calling telephone receives five tone bursts. To answer callback rings, lift the handset. The called telephone will ring.", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [ 349973 ], "anchor_spans": [ [ 31, 42 ] ] }, { "plaintext": "To cancel auto call back before it rings, press \"ITCM\", dial \"#6\" and hang up. ", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Comdial Digital Impression", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [ 2241700 ], "anchor_spans": [ [ 0, 7 ] ] }, { "plaintext": "When you reach a station that is busy or does not answer, press CAMP. When the phone you wish to reach becomes idle, your phone will ring with five short tones. Press ITCM to cause the other phone to ring. ", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "To cancel the callback, press ITCM and dial \"#6\".", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "If the extension you call in voice announce mode is not answered, press ITCM before pressing CAMP.", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Database Systems Corp. PACER Phone System", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Custom callback is integrated into the CRM application that signals the phone system to redial a number on a particular date and time. Call is automatically assigned to the original agent or assigned to a hunt group associated with a particular campaign.", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Executone Encore CX", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Press CALLBK when you hear the busy tone. Answer the callback by lifting the handset or pressing MON. ", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Inter-Tel Eclipse IDS Integrated Operator Terminal", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Press the Call Back key at the busy signal. Press the RLS key. When your line is free and the extension you called is idle, your extension will ring. When the calls rings back to you, press the RLS key.", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Inter-Tel Eclipse2", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Associate Display and Basic Digital Phone", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Press \"6\" at the busy signal and hang up. Your phone will ring when the extension if available. Press \"6\" again to cancel before you get your callback.", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Isoetec Digital Systems", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Display/Data Phone", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Press \"Cb.\" Soft key at the busy signal. Replace the handset or press \"HF\". Wait for the double tone. When the extension is no longer busy, it will automatically call you back.", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Isoetec IDS M Series Telephones", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "When you hear the busy signal, press the \"CALL BACK\" key. Hang up. When you are signaled, lift the handset or press the \"HF\" key. Press the blinking \"CALL BACK\" key. ", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "PCS Digital Telephone ", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Press \"cbck\" at the busy signal. When a station is available, pick up the handset.", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "To cancel, press \"del\".", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Vodavi StarPlus Phone System", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Press the pre-programmed CALL BACK button. Hang up. When the busy station becomes available, you will be signaled. ", "section_idx": 1, "section_name": "Using callback on popular business telephone systems", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " redial", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 40755 ], "anchor_spans": [ [ 1, 7 ] ] }, { "plaintext": " Vertical service code", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 417914 ], "anchor_spans": [ [ 1, 22 ] ] } ]

[ "Calling_features" ]

[]

[ { "plaintext": "An automated call distribution system, commonly known as automatic call distributor (ACD), is a telephony device that answers and distributes incoming calls to a specific group of terminals or agents within an organization. ACDs often use a voice menu to direct callers based on the customer's selection, telephone number, selected incoming line to the system or time of day the call was processed. Computer telephony integration (CTI) and computer-supported telecommunications applications (CSTA) are intermediate software that can produce advanced ACD systems. ACD systems often use information gathered in an IVR as input to improve routing efficiency. Experts claim that \"the invention of ACD technology made the concept of a call centre possible.\"", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 41831, 655822, 162190, 1184037, 162186, 7243 ], "anchor_spans": [ [ 96, 105 ], [ 106, 112 ], [ 399, 429 ], [ 440, 490 ], [ 612, 615 ], [ 730, 741 ] ] }, { "plaintext": "Private Branch Exchange (PBX) was a telephone exchange device that acted as a mini-switchboard to route phone calls. The closed nature of PBXs limited flexibility, and a system was designed to enable common computing devices to make routing decisions. The automated form of this technology developed into the automated call distribution system, where issued information about incoming calls would direct a response.", "section_idx": 1, "section_name": "Background", "target_page_ids": [ 1017561, 26668156 ], "anchor_spans": [ [ 0, 23 ], [ 36, 54 ] ] }, { "plaintext": "Although ACDs appeared in the 1950s, one of the first large and separate ACDs was a modified 5XB switch used by the New York Telephone Company in the early 1970s to distribute calls among hundreds of 4-1-1 information operators. Robert Hirvela developed and received a patent for technology that was used to create the Rockwell Galaxy Automatic Call Distributor, which was used by Continental Airlines for more than 20 years. Since then, ACDs have integrated incoming call management and voice messaging software into its capabilities.", "section_idx": 1, "section_name": "Background", "target_page_ids": [ 8222445, 2324412, 296753, 113558 ], "anchor_spans": [ [ 93, 103 ], [ 116, 142 ], [ 200, 205 ], [ 381, 401 ] ] }, { "plaintext": "ACDs route incoming calls to the most qualified employee or employees within a company that can address a caller's needs. The technology can also use rule-based instructions such as caller ID, automatic number identification, interactive voice response or dialed number identification services to determine how calls are handled. ACD systems are often found in offices that handle large volumes of incoming phone calls from callers who have no need to talk to a specific person, but require assistance from any of multiple persons (e.g., customer service representatives or emergency services dispatch centers) at the earliest opportunity. ", "section_idx": 2, "section_name": "Application", "target_page_ids": [ 162281, 250906, 162186, 2439028, 406703 ], "anchor_spans": [ [ 182, 191 ], [ 193, 224 ], [ 226, 252 ], [ 256, 293 ], [ 407, 417 ] ] }, { "plaintext": "There are several contact routing strategies that can be set up within an algorithm based on a company's needs. Skills-based routing is determined by an operator's knowledge to handle a caller's inquiry. Virtual contact centers can also be used to aggregate the skill sets of agents to help multiple vendors, where all real-time and statistical information can be shared amongst the contact center sites. An additional function for these external routing applications is to enable Computer telephony integration (CTI), which improves efficiency for call center agents by matching incoming phone calls with relevant data via screen pop.", "section_idx": 2, "section_name": "Application", "target_page_ids": [ 7573262, 7243, 162190, 3100556 ], "anchor_spans": [ [ 112, 132 ], [ 204, 227 ], [ 481, 511 ], [ 624, 634 ] ] }, { "plaintext": "The system has been met with criticism for making small improvements based on customer feedback. In Florida, ACD technology was installed in several counties for 9-1-1 operators to aid in unanswered phone calls. However, call-takers are not familiar with the geography of the entire county due to the automated system sending calls to the first available responder.", "section_idx": 3, "section_name": "Criticism", "target_page_ids": [ 18933066, 146296 ], "anchor_spans": [ [ 100, 107 ], [ 162, 167 ] ] }, { "plaintext": "There are multiple choices for distributing incoming calls from a queue", "section_idx": 4, "section_name": "Distribution methods", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Linear Call Distribution – Calls are distributed in order, starting at the beginning each time", "section_idx": 4, "section_name": "Distribution methods", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Circular/Rotary Call Distribution – Calls are distributed in order, starting with the next in order", "section_idx": 4, "section_name": "Distribution methods", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Uniform Call Distribution – Calls are distributed uniformly, starting with the person who has handled the fewest calls", "section_idx": 4, "section_name": "Distribution methods", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Simultaneous Call Distribution – Calls are presented to all available extensions simultaneously", "section_idx": 4, "section_name": "Distribution methods", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Weighted Call Distribution – Calls are distributed according to a configurable weighting, such as differing skill sets within customer service representatives", "section_idx": 4, "section_name": "Distribution methods", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Number Five Crossbar Switching System", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 8222445 ], "anchor_spans": [ [ 0, 37 ] ] }, { "plaintext": "Communications system", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 40925 ], "anchor_spans": [ [ 0, 21 ] ] }, { "plaintext": "Vector directory number", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 15855590 ], "anchor_spans": [ [ 0, 23 ] ] }, { "plaintext": "Zip tone", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 2659980 ], "anchor_spans": [ [ 0, 8 ] ] } ]

[ "Telephone_exchanges", "Computer_telephony_integration", "Telephony_equipment" ]

[ "automatic call distribution system", "ACD" ]

[ { "plaintext": "Automatic data processing (ADP) may refer to:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Automatic Data Processing, a computing services company.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 1212868 ], "anchor_spans": [ [ 1, 26 ] ] }, { "plaintext": " Data processing using mechanical or electronic equipment, Electronic data processing", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 41961, 462545 ], "anchor_spans": [ [ 1, 16 ], [ 59, 85 ] ] } ]

[]

[]

[ { "plaintext": "Automatic Link Establishment, commonly known as ALE, is the worldwide de facto standard for digitally initiating and sustaining HF radio communications. ALE is a feature in an HF communications radio transceiver system that enables the radio station to make contact, or initiate a circuit, between itself and another HF radio station or network of stations. The purpose is to provide a reliable rapid method of calling and connecting during constantly changing HF ionospheric propagation, reception interference, and shared spectrum use of busy or congested HF channels.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 172734, 178937, 346001 ], "anchor_spans": [ [ 70, 87 ], [ 128, 130 ], [ 281, 288 ] ] }, { "plaintext": "A standalone ALE radio combines an HF SSB radio transceiver with an internal microprocessor and MFSK modem. It is programmed with a unique ALE address, similar to a phone number (or on newer generations, a username). When not actively in contact with another station, the HF SSB transceiver constantly scans through a list of HF frequencies called channels, listening for any ALE signals transmitted by other radio stations. It decodes calls and soundings sent by other stations and uses the bit error rate to store a quality score for that frequency and sender-address.", "section_idx": 1, "section_name": "Mechanism", "target_page_ids": [ 178937, 29048, 5218, 2371591, 20647197, 2048145, 40756, 40794 ], "anchor_spans": [ [ 35, 37 ], [ 38, 41 ], [ 77, 91 ], [ 96, 100 ], [ 101, 106 ], [ 143, 150 ], [ 446, 455 ], [ 492, 506 ] ] }, { "plaintext": "To reach a specific station, the caller enters the ALE Address. On many ALE radios this is similar to dialing a phone number. The ALE controller selects the best available idle channel for that destination address. After confirming the channel is indeed idle, it then sends a brief selective calling signal identifying the intended recipient. When the distant scanning station detects ALE activity, it stops scanning and stays on that channel until it can confirm whether or not the call is for it. The two stations' ALE controllers automatically handshake to confirm that a link of sufficient quality has been established, then notify the operators that the link is up. If the callee fails to respond or the handshaking fails, the originating ALE node usually selects another frequency either at random or by making a guess of varying sophistication.", "section_idx": 1, "section_name": "Mechanism", "target_page_ids": [ 7342571, 41229 ], "anchor_spans": [ [ 282, 299 ], [ 547, 556 ] ] }, { "plaintext": "Upon successful linking, the receiving station generally emits an audible alarm and shows a visual alert to the operator, thus indicating the incoming call. It also indicates the callsign or other identifying information of the linked station, similar to Caller ID. The operator then un-mutes the radio and answers the call then can talk in a regular conversation or negotiates a data link using voice or the ALE built-in short text message format. Alternatively, digital data can be exchanged via a built-in or external modem (such as a STANAG 5066 or MIL-STD-188-110B serial tone modem) depending on needs and availability. The ALE built-in text messaging facility can be used to transfer short text messages as an \"orderwire\" to allow operators to coordinate external equipment such as phone patches or non-embedded digital links, or for short tactical messages. ", "section_idx": 1, "section_name": "Mechanism", "target_page_ids": [ 162281, 141283, 41882 ], "anchor_spans": [ [ 255, 264 ], [ 538, 549 ], [ 553, 569 ] ] }, { "plaintext": "Due to the vagaries of ionospheric communications, HF radio as used by large governmental organizations in the mid-20th century was traditionally the domain of highly skilled and trained radio operators. One of the new characteristics that embedded microprocessors and computers brought to HF radio via ALE, was alleviation of the need for the radio operator to constantly monitor and change the radio frequency manually to compensate for ionospheric conditions or interference. For the average user of ALE, after learning how to work the basic functions of the HF transceiver, it became similar to operating a cellular mobile phone. For more advanced functions and programming of ALE controllers and networks, it became similar to the use of menu-enabled consumer equipment or the optional features typically encountered in software. In a professional or military organization, this does not eliminate the need for skilled and trained communicators to coordinate the per-unit authorized frequency lists and node addresses it merely allows the deployment of relatively unskilled technicians as \"field communicators\" and end-users of the existing coordinated architecture.", "section_idx": 2, "section_name": "Operator skill", "target_page_ids": [ 406283, 189768, 5309 ], "anchor_spans": [ [ 743, 755 ], [ 756, 774 ], [ 825, 833 ] ] }, { "plaintext": "An ALE radio system enables connection for voice conversation, alerting, data exchange, texting, instant messaging, email, file transfer, image, geo-position tracking, or telemetry. With a radio operator initiating a call, the process normally takes a few minutes for the ALE to pick an HF frequency that is optimum for both sides of the communication link. It signals the operators audibly and visually on both ends, so they can begin communicating with each other immediately. In this respect, the longstanding need in HF radio for repetitive calling on pre-determined time schedules or tedious monitoring static is eliminated. It is useful as a tool for finding optimum channels to communicate between stations in real-time. In modern HF communications, ALE has largely replaced HF prediction charts, propagation beacons, chirp sounders, propagation prediction software, and traditional radio operator educated guesswork. ALE is most commonly used for hooking up operators for voice contacts on SSB (single-sideband modulation), HF internet connectivity for email, SMS phone texting or text messaging, real-time chat via HF text, Geo Position Reporting, and file transfer. High Frequency Internet Protocol or HFIP may be used with ALE for internet access via HF.", "section_idx": 3, "section_name": "Common applications", "target_page_ids": [ 11866, 29048, 28207, 305854, 11296576 ], "anchor_spans": [ [ 145, 157 ], [ 1003, 1029 ], [ 1068, 1071 ], [ 1089, 1103 ], [ 1176, 1208 ] ] }, { "plaintext": "The essence of ALE techniques is the use of automatic channel selection, scanning receivers, selective calling, handshaking, and robust burst modems. An ALE node decodes all received ALE signals heard on the channel(s) it monitors. It uses the fact that all ALE messages use forward error correction (FEC) redundancy. By noting how much error-correction occurred in each received and decoded message, an ALE node can detect the \"quality\" of the path between the sending station and itself. This information is coupled with the ALE address of the sending node and the channel the message was received on, and stored in the node's Link Quality Analysis (LQA) memory. When a call is initiated, the LQA lookup table is searched for matches involving the target ALE address and the best historic channel is used to call the target station. This reduces the likelihood that the call has to be repeated on alternate frequencies. Once the target station has heard the call and responded, a bell or other signalling device will notify both operators that a link has been established. At this point, the operators may coordinate further communication via orderwire text messages, voice, or other means. If further digital communication is desired, it may take place via external data modems or via optional modems built into the ALE terminal.", "section_idx": 4, "section_name": "Techniques", "target_page_ids": [ 7342571, 41229, 4237207, 2048145, 356457 ], "anchor_spans": [ [ 93, 110 ], [ 112, 123 ], [ 275, 299 ], [ 527, 538 ], [ 699, 711 ] ] }, { "plaintext": "This unusual usage of FEC redundancy is the primary innovation that differentiates ALE from previous selective calling systems which either decoded a call or failed to decode due to noise or interference. A binary outcome of \"Good enough\" or not gave no way of automatically choosing between two channels, both of which are currently good enough for minimum communications. The redundancy-based scoring inherent in ALE thus allows for selecting the \"best\" available channel and (in more advanced ALE nodes) using all decoded traffic over some time window to sort channels into a list of decreasing probability-to-contact, significantly reducing co-channel interference to other users as well as dramatically decreasing the time needed to successfully link with the target node.", "section_idx": 4, "section_name": "Techniques", "target_page_ids": [ 7342571 ], "anchor_spans": [ [ 101, 118 ] ] }, { "plaintext": "Techniques used in the ALE standard include automatic signaling, automatic station identification (sounding), polling, message store-and-forward, linking protection and anti-spoofing to prevent hostile denial of service by ending the channel scanning process. Optional ALE functions include polling and the exchange of orderwire commands and messages. The orderwire message, known as AMD (Automatic Message Display), is the most commonly used text transfer method of ALE, and the only universal method that all ALE controllers have in common for displaying text. It is common for vendors to offer extensions to AMD for various non-standard features, although dependency on these extensions undermines interoperability. As in all interoperability scenarios, care should be taken to determine if this is acceptable before using such extensions.", "section_idx": 4, "section_name": "Techniques", "target_page_ids": [ 41703, 40756, 4516638, 41367, 604831, 503209, 2621372 ], "anchor_spans": [ [ 54, 63 ], [ 99, 107 ], [ 110, 117 ], [ 119, 126 ], [ 127, 144 ], [ 174, 182 ], [ 319, 328 ] ] }, { "plaintext": "ALE evolved from older HF radio selective calling technology. It combined existing channel-scanning selective calling concepts with microprocessors (enabling FEC decoding and quality scoring decisions), burst transmissions (minimizing co-channel interference), and transponding (allowing unattended operation and incoming-call signalling). Early ALE systems were developed in the late 1970s and early 1980s by several radio manufacturers. The first ALE-family controller units were external rack mounted controllers connected to control military radios, and were rarely interoperable across vendors.", "section_idx": 5, "section_name": "History and precedents", "target_page_ids": [ 7342571 ], "anchor_spans": [ [ 32, 49 ] ] }, { "plaintext": "Various methods and proprietary digital signaling protocols were used by different manufacturers in first generation ALE, leading to incompatibility. Later, a cooperative effort among manufacturers and the US government resulted in a second generation of ALE that included the features of first generation systems, while improving performance. The second generation 2G ALE system standard in 1986, MIL-STD-188-141A, was adopted in FED-STD-1045 for US federal entities. In the 1980s, military and other entities of the US government began installing early ALE units, using ALE controller products built primarily by US companies. The primary application during the first 10 years of ALE use was government and military radio systems, and the limited customer base combined with the necessity to adhere to MILSPEC standards kept prices extremely high. Over time, demand for ALE capabilities spread and by the late 1990s, most new government HF radios purchased were designed to meet at least the minimum ALE interoperability standard, making them eligible for use with standard ALE node gear. Radios implementing at least minimum ALE node functionality as an option internal to the radio became more common and significantly more affordable. As the standards were adopted by other governments worldwide, more manufacturers produced competitively priced HF radios to meet this demand. The need to interoperate with government organizations prompted many non-government organizations (NGOs) to at least partially adopt ALE standards for communication. As non-military experience spread and prices came down, other civilian entities started using 2G ALE. By the year 2000, there were enough civilian and government organizations worldwide using ALE that it became a de facto HF interoperability standard for situations where a priori channel and address coordination is possible.", "section_idx": 5, "section_name": "History and precedents", "target_page_ids": [ 2336660, 41285, 46539, 41285 ], "anchor_spans": [ [ 805, 812 ], [ 1007, 1023 ], [ 1453, 1480 ], [ 1775, 1791 ] ] }, { "plaintext": "In the late 1990s, a third generation 3G ALE with significantly improved capability and performance was included in MIL-STD-188-141B, retaining backward compatibility with 2G ALE, and was adopted in NATO STANAG 4538. Civilian and non-government adoption rates are much lower than 2G ALE due to the extreme cost as compared to surplus or entry-level 2G gear as well as the significantly increased system and planning complexity necessary to realize the benefits inherent in the 3G specification. For many militaries, whose needs for maximized intra-organizational capability and capacity always strain existing systems, the additional cost and complexity of 3G are less problematic.", "section_idx": 5, "section_name": "History and precedents", "target_page_ids": [ 21133 ], "anchor_spans": [ [ 199, 203 ] ] }, { "plaintext": "ALE enables rapid unscheduled communication and message passing without requiring complex message centers, multiple radios and antennas, or highly trained operators. With the removal of these potential sources of failure, the tactical communication process becomes much more robust and reliable. The effects extend beyond mere force multiplication of existing communications methods; units such as helicopters, when outfitted with ALE radios, can now reliably communicate in situations where the crew are too busy to operate a traditional non-line of sight radio. This ability to enable tactical communication in conditions where dedicated trained operators and hardware are inappropriate is often considered to be the true improvement offered by ALE.", "section_idx": 5, "section_name": "History and precedents", "target_page_ids": [ 2264109, 60455 ], "anchor_spans": [ [ 327, 347 ], [ 543, 556 ] ] }, { "plaintext": "ALE is a critical path toward increased interoperability between organizations. By enabling a station to participate nearly simultaneously in many different HF networks, ALE allows for convenient cross-organization message passing and monitoring without requiring dedicated separate equipment and operators for each partner organization. This dramatically reduces staffing and equipment considerations, while enabling small mobile or portable stations to participate in multiple networks and subnetworks. The result is increased resilience, decreased fragility, increased ability to communicate information effectively, and the ability to rapidly add to or replace communication points as the situation demands.", "section_idx": 5, "section_name": "History and precedents", "target_page_ids": [ 41285 ], "anchor_spans": [ [ 40, 56 ] ] }, { "plaintext": "When combined with Near Vertical Incidence Skywave (NVIS) techniques and sufficient channels spread across the spectrum, an ALE node can provide greater than 95% success linking on the first call, nearly on par with SATCOM systems. This is significantly more reliable than cellphone infrastructure during disasters or wars yet is mostly immune to such considerations itself.", "section_idx": 5, "section_name": "History and precedents", "target_page_ids": [ 2860618, 45207 ], "anchor_spans": [ [ 19, 50 ], [ 216, 222 ] ] }, { "plaintext": "Global standards for ALE are based on the original US MIL-STD 188-141A and FED-1045, known as 2nd Generation (2G) ALE. 2G ALE uses non-synchronised scanning of channels, and it takes several seconds to half a minute to repeatedly scan through an entire list of channels looking for calls. Thus it requires sufficient duration of transmission time for calls to connect or link with another station that is unsynchronised with its calling signal. The vast majority of ALE systems in use in the world at the present time are 2G ALE.", "section_idx": 6, "section_name": "Standards and protocols", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The more common 2G ALE signal waveform is designed to be compatible with standard 3kHz SSB narrowband voice channel transceivers. The modulation method is 8ary Frequency Shift Keying or 8FSK, also sometimes called Multi Frequency Shift Keying MFSK, with eight orthogonal tones between 750 and 2500Hz. Each tone is 8 ms long, resulting in a transmitted over-the-air symbol rate of 125 baud or 125 symbols per second, with a raw data rate of 375 bits per second. The ALE data is formatted in 24-bit frames, which consist of a 3-bit preamble followed by three ASCII characters, each seven bits long. The received signal is usually decoded using digital signal processing techniques that are capable of recovering the 8FSK signal at a negative decibel signal-to-noise ratio (i.e., the signal may be recovered even when it is below the noise level). The over-the-air layers of the protocol involve the use of forward error correction, redundancy, and handshaking transponding similar to those used in ARQ techniques.", "section_idx": 6, "section_name": "Standards and protocols", "target_page_ids": [ 2371591, 8525, 4237207, 1953582, 41229, 40726 ], "anchor_spans": [ [ 243, 247 ], [ 642, 667 ], [ 904, 928 ], [ 930, 940 ], [ 946, 957 ], [ 996, 999 ] ] }, { "plaintext": "Newer standards of ALE, called 3rd Generation or 3G ALE, use accurate time synchronization (via a defined time-synch protocol as well as the option of GPS-locked clocks) to achieve faster and more dependable linking. Through synchronization, the calling time to achieve a link may be reduced to less than 10 seconds. The 3G ALE modem signal also provides better robustness and can work in channel conditions that are less favorable than 2G ALE. Dwell groups, limited callsigns, and shorter burst transmissions enable more rapid intervals of scanning. All stations in the same group scan and receive each channel at precisely the same time window. Although 3G ALE is more reliable and has significantly enhanced channel-time efficiency, the existence of a large installed base of 2G ALE radio systems and the wide availability of moderately priced (often military surplus) equipment, has made 2G the baseline standard for global interoperability.", "section_idx": 6, "section_name": "Standards and protocols", "target_page_ids": [ 11866, 27206541, 2916649 ], "anchor_spans": [ [ 151, 154 ], [ 362, 372 ], [ 761, 775 ] ] }, { "plaintext": "Interoperability is a critical issue for the disparate entities which use radiocommunications to fulfill the needs of organizations. Largely due to the ubiquity of 2G ALE, it became the primary method for providing interoperability on HF between governmental and non-governmental disaster relief and emergency communications entities, and amateur radio volunteers. With digital techniques increasingly employed in communications equipment, a universal digital calling standard was needed, and ALE filled the gap. Nearly every major HF radio manufacturer in the world builds ALE radios to the 2G standard to meet the high demand that new installations of HF radio systems conform to this standard protocol. Disparate entities that historically used incompatible radio methods were then able to call and converse with each other using the common 2G ALE platform. Some manufacturers and organizations have used the AMD feature of ALE to expand the performance and connectivity. In some cases, this has been successful, and in other cases, the use of proprietary preamble or embedded commands has led to interoperability problems.", "section_idx": 7, "section_name": "Basis for HF interoperability communications", "target_page_ids": [ 41285, 46539, 81196 ], "anchor_spans": [ [ 0, 16 ], [ 263, 279 ], [ 851, 859 ] ] }, { "plaintext": "ALE serves as a convenient method of beyond line of sight communication. Originally developed to support military requirements, ALE is useful to many organizations who find themselves managing widely located units. United States Immigration and Customs Enforcement and United States Coast Guard are two members of the Customs Over the Horizon Enforcement Network (COTHEN), a MIL-STD 188-141A ALE network. All U.S. armed forces operate multiple similar networks. Similarly, shortwave utility listeners have documented frequency and callsign lists for many nations' military and guard units, as well as networks operated by oil exploration and production companies and public utilities in many countries.", "section_idx": 7, "section_name": "Basis for HF interoperability communications", "target_page_ids": [ 216537, 32223 ], "anchor_spans": [ [ 215, 264 ], [ 269, 294 ] ] }, { "plaintext": "ALE radio communication systems for both HF regional area networks and HF interoperability communications are in service among emergency and disaster relief agencies as well as military and guard forces. Extraordinary response agencies and organizations use ALE to respond to situations in the world where conventional communications may have been temporarily overloaded or damaged. In many cases, it is in place as alternative back-channel for organizations that may have to respond to situations or scenarios involving the loss of conventional communications. Earthquakes, storms, volcanic eruptions, and power or communication infrastructure failures are typical situations in which organizations may deem ALE necessary to operations. ALE networks are common among organizations engaged in extraordinary situation response such as: natural and man-made disasters, transportation, power, or telecommunication network failures, war, peacekeeping, or stability operations. Organizations known to use ALE for Emergency management, disaster relief, ordinary communication or extraordinary situation response include: Red Cross, FEMA, Disaster Medical Assistance Teams, NATO, Federal Bureau of Investigation, United Nations, AT&T, Civil Air Patrol, SHARES, State of California Emergency Management Agency (CalEMA), other US States' Offices of Emergency Services or Emergency Management Agencies, and Amateur Radio Emergency Service (ARES).", "section_idx": 7, "section_name": "Basis for HF interoperability communications", "target_page_ids": [ 1455589, 4345474, 73797, 3274996, 21133, 11127, 31769, 17555269, 14298059, 5407, 414182 ], "anchor_spans": [ [ 1008, 1028 ], [ 1115, 1124 ], [ 1126, 1130 ], [ 1132, 1164 ], [ 1167, 1171 ], [ 1173, 1204 ], [ 1206, 1220 ], [ 1222, 1226 ], [ 1228, 1244 ], [ 1263, 1273 ], [ 1397, 1428 ] ] }, { "plaintext": "The International Telecommunication Union (ITU), in response to the need for interoperation in international disaster response spurred largely by humanitarian relief, included ALE in its Telecommunications for Disaster Relief recommendations. The increasing need for instant connectivity for logistical and tactical disaster relief response communications, such as the 2004 Indian Ocean earthquake tsunami led to ITU actions of encouragement to countries around the world toward loosening restrictions on such communications and equipment border transit during catastrophic disasters. The IARU Global Amateur Radio Emergency Communications Conferences (GAREC) and IARU Global Simulated Emergency Tests have included ALE.", "section_idx": 7, "section_name": "Basis for HF interoperability communications", "target_page_ids": [ 14836, 2455369, 1328236, 31161, 12751711 ], "anchor_spans": [ [ 4, 41 ], [ 187, 225 ], [ 369, 397 ], [ 398, 405 ], [ 594, 650 ] ] }, { "plaintext": "Amateur radio operators began sporadic ALE operation on a limited basis in the early to mid-1990s, with commercial ALE radios and ALE controllers. In 2000, the first widely available software ALE controller for the Personal Computer, PCALE, became available, and hams started to set up stations based on it. In 2001, the first organized and coordinated global ALE nets for International Amateur Radio began. In August 2005, ham radio operators supporting communications for emergency Red Cross shelters used ALE for Disaster Relief operations during the Hurricane Katrina disaster. After the event, hams developed more permanent ALE emergency/disaster relief networks, including internet connectivity, with a focus on interoperation between organizations. The amateur radio HFLink Automatic Link Establishment system uses an open net protocol to enable all amateur radio operators and amateur radio nets worldwide to participate in ALE and share the same ALE channels legally and interoperably. Amateur radio operators may use it to call each other for voice or data communications.", "section_idx": 8, "section_name": "Use in amateur radio", "target_page_ids": [ 23275402, 4345474, 2569378 ], "anchor_spans": [ [ 0, 13 ], [ 484, 493 ], [ 554, 571 ] ] }, { "plaintext": "Amateur radio operators commonly provide local, regional, national, and international emergency / disaster relief communications. The need for interoperability on HF led to the adoption of Automatic Link Establishment ALE open networks by hams. Amateur radio adapted 2G ALE techniques, by using the common denominators of the 2G ALE protocol, with a limited subset of features found in the majority of all ALE radios and controllers. Each amateur radio ALE station uses the operator's call sign as the address, also known as the ALE Address, in the ALE radio controller. The lowest common denominator technique enables any manufacturer's ALE radios or software to be used for HF interoperability communications and networking. Known as Ham-Friendly ALE, the amateur radio ALE standard is used to establish radio communications, through a combination of active ALE on internationally recognized automatic data frequencies, and passive ALE scanning on voice channels. In this technique, active ALE frequencies include pseudorandom periodic polite station identification, while passive ALE frequencies are silently scanned for selective calling. ALE systems include Listen Before Transmit as a standard function, and in most cases this feature provides better busy channel detection of voice and data signals than the human ear. Ham-Friendly ALE technique is also known as 2.5G ALE, because it maintains 2G ALE compatibility while employing some of the adaptive channel management features of 3G ALE, but without the accurate GPS time synchronization of 3G ALE.", "section_idx": 8, "section_name": "Use in amateur radio", "target_page_ids": [ 2797722, 2048145, 378200, 804074, 23210, 11866 ], "anchor_spans": [ [ 485, 494 ], [ 502, 509 ], [ 575, 600 ], [ 806, 811 ], [ 1016, 1028 ], [ 1523, 1526 ] ] }, { "plaintext": "Hot standby ALE nets are in constant operation 24/7/365 for International Emergency and Disaster Relief communications. The Ham Radio Global ALE High Frequency Network, which began service in June 2007, is the world's largest intentionally open ALE network. It is a free open network staffed by volunteers, and used by amateur radio operators supporting disaster relief organizations.", "section_idx": 8, "section_name": "Use in amateur radio", "target_page_ids": [ 3218818, 422855, 1455589, 46545 ], "anchor_spans": [ [ 0, 11 ], [ 47, 55 ], [ 88, 103 ], [ 249, 256 ] ] }, { "plaintext": "International amateur radio ALE High Frequency channels are frequency coordinated with all Regions of the International Amateur Radio Union (IARU entity of ITU), for international, regional, national, and local use in the Amateur Radio Service. All Amateur Radio ALE channels use \"USB\" Upper Sideband standard. Different rules, regulations, and bandplans of the region and local country of operation apply to use of various channels. Some channels may not be available in every country. Primary or global channels are in common with most countries and regions.", "section_idx": 8, "section_name": "Use in amateur radio", "target_page_ids": [ 178937, 41701 ], "anchor_spans": [ [ 32, 46 ], [ 292, 300 ] ] }, { "plaintext": "This listing is current as of February 2020. See HFLINK for more information about Amateur Radio Service ALE Automatic Link Establishment.", "section_idx": 8, "section_name": "Use in amateur radio", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Frequency table notes: ", "section_idx": 8, "section_name": "Use in amateur radio", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Automatic Link Establishment ALE channel frequencies in the Amateur Radio Service are internationally coordinated with selective calling Selcall channels for interoperability purposes. ", "section_idx": 8, "section_name": "Use in amateur radio", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Net is the ALE net address or Selcall net name.", "section_idx": 8, "section_name": "Use in amateur radio", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Multiple frequency-shift keying", "section_idx": 9, "section_name": "See also", "target_page_ids": [ 2371591 ], "anchor_spans": [ [ 1, 32 ] ] }, { "plaintext": " Selective calling", "section_idx": 9, "section_name": "See also", "target_page_ids": [ 7342571 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Amateur radio", "section_idx": 9, "section_name": "See also", "target_page_ids": [ 23275402 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " Amateur radio emergency communications", "section_idx": 9, "section_name": "See also", "target_page_ids": [ 3687749 ], "anchor_spans": [ [ 1, 39 ] ] }, { "plaintext": " ARES", "section_idx": 9, "section_name": "See also", "target_page_ids": [ 414182 ], "anchor_spans": [ [ 1, 5 ] ] } ]

[ "Military_communications", "Telecommunications_engineering", "Signal_processing", "Quantized_radio_modulation_modes", "Amateur_radio" ]

[]

[ { "plaintext": "Automatic message exchange (AME): In an adaptive high-frequency (HF) radio network, an automated process allowing the transfer of a message from message injection to addressee reception, without human intervention. Through the use of machine-addressable transport guidance information, i.e., the message header, the message is automatically routed through an on-line direct connection through single or multiple transmission media.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 178937, 224694, 1915393, 41367, 18985062, 472401, 346001, 609152 ], "anchor_spans": [ [ 50, 64 ], [ 70, 83 ], [ 119, 127 ], [ 133, 140 ], [ 275, 286 ], [ 306, 312 ], [ 376, 386 ], [ 414, 426 ] ] }, { "plaintext": "Source: from Federal Standard 1037C", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 37310 ], "anchor_spans": [ [ 13, 35 ] ] } ]

[ "Radio_technology" ]

[]

[ { "plaintext": "In telecommunication, an automatic redial is a service feature that allows the user to dial, by depressing a single key or a few keys, the most recent telephone number dialed at that instrument.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 417914, 2052479, 18790468 ], "anchor_spans": [ [ 3, 20 ], [ 47, 62 ], [ 79, 83 ], [ 151, 167 ] ] }, { "plaintext": "Note: Automatic redial is often associated with the telephone instrument, but may be provided by a PBX, or by the central office. Synonym last number redial. Contrast with automatic calling unit.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 30003, 1017561, 26668156, 33564739 ], "anchor_spans": [ [ 52, 61 ], [ 99, 102 ], [ 114, 128 ], [ 172, 194 ] ] }, { "plaintext": "Often one must subscribe to a caller ID for use of this function on a landline.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] } ]

[ "Calling_features", "Telecommunications" ]

[]

[ { "plaintext": "In telecommunication, automatic sounding is the testing of selected channels for quality by providing a very brief identifying transmission that may be used by other stations to evaluate connectivity, and availability, and to identify known working channels for immediate or later use for communications or calling. They are often used to maintain connectivity in digital communications high frequency radio networks.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 40760, 33094374, 346001, 57980 ], "anchor_spans": [ [ 3, 20 ], [ 205, 217 ], [ 289, 303 ], [ 348, 360 ], [ 387, 407 ] ] }, { "plaintext": "Automatic soundings are primarily intended to increase the efficiency of the automatic link establishment (ALE) function, thereby increasing system throughput. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 40753, 30932 ], "anchor_spans": [ [ 77, 105 ], [ 148, 158 ] ] }, { "plaintext": "In ALE, the sounding information consists of a heavily error-corrected short message identifying the sender. Recipients decode it and use the bit error rate to calculate and store a (channel, node, quality) tuple. As ionospheric conditions and mobile-node locations change, these quality tuples will shift. The stored data can be used to maximize the chance that the best channel to link with a given partner will be chosen first.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 4237207, 40794, 1041142 ], "anchor_spans": [ [ 55, 70 ], [ 142, 156 ], [ 207, 212 ] ] } ]

[ "Communication_circuits", "Radio_frequency_propagation_fading" ]

[]

[ { "plaintext": "In data communications, an automatic switching system is a switching system in which all the operations required to execute the three phases of Information transfer transactions are automatically executed in response to signals from a user end-instrument. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 18985040, 33094374, 41101, 47867, 2052479 ], "anchor_spans": [ [ 3, 7 ], [ 8, 22 ], [ 59, 75 ], [ 144, 164 ], [ 235, 239 ] ] }, { "plaintext": "In an automatic switching system, the information-transfer transaction is performed without human intervention, except for initiation of the access phase and the disengagement phase by a user. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 41262 ], "anchor_spans": [ [ 38, 70 ] ] }, { "plaintext": "In telephony, it refers to a telephone exchange in which all the operations required to set up, supervise, and release connections required for telephone calls are automatically performed in response to signals from a calling device. This distinction lost importance as manual switching declined during the 20th century.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 41831, 26668156, 2950225, 406703, 28427 ], "anchor_spans": [ [ 3, 12 ], [ 29, 47 ], [ 96, 105 ], [ 144, 158 ], [ 271, 287 ] ] } ]

[ "Telephone_exchange_equipment" ]

[]

[ { "plaintext": "Auxiliary power is electric power that is provided by an alternate source and that serves as backup for the primary power source at the station main bus or prescribed sub-bus.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 3270043, 1029195 ], "anchor_spans": [ [ 19, 33 ], [ 149, 152 ] ] }, { "plaintext": "An offline unit provides electrical isolation between the primary power source and the critical technical load whereas an online unit does not.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "A Class A power source is a primary power source, i.e., a source that assures an essentially continuous supply of power.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Types of auxiliary power services include Class B, a standby power plant to cover extended outages of the order of days; Class C, a 10-to-60-second quick-start unit to cover short-term outages of the order of hours; and Class D, an uninterruptible non-break unit using stored energy to provide continuous power within specified voltage and frequency tolerances.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 212141, 10779 ], "anchor_spans": [ [ 67, 72 ], [ 340, 349 ] ] }, { "plaintext": "Many uses and implementations of auxiliary power are experimented with to increase its efficiency. One such experimentation was to find a better way to operate a diesel engine with fuel cell based auxiliary power units.  The method of which is to separate hydrogen-rich gas from the diesel fuel to generate electricity separately in an auxiliary power unit.  With this process, an effective reduction in emissions can be achieved by lowering the consumed volume of gas per hour. However, upon  power demands reaching 60% a sharp decrease in performance occurs, which can be solved by using a diesel or kerosine fuel with a maximum CO concentration of 1.5%.", "section_idx": 2, "section_name": "Uses/Implementations", "target_page_ids": [ 8540, 11729, 13255, 81761, 9550 ], "anchor_spans": [ [ 162, 175 ], [ 181, 190 ], [ 256, 264 ], [ 283, 294 ], [ 307, 318 ] ] }, { "plaintext": "There are a variety of other implementations of auxiliary power units in energy systems. This explains for how a significant portion of emissions come from commercial vehicles.  Diesel engines operating within densely populated areas, running within an ineffective range in order to power their auxiliary systems, such as refrigeration, are contributors to a large portion of the emissions from automobiles.  Using a model with a diesel powered four-stroke engine on a truck with 100% load capacity driving a combination of typical urban and city road cycles, emissions and auxiliary power demand were recorded. Then by using the calculated auxiliary power demand, a source was developed to support the demand for the auxiliary systems in the form of a PEM fuel cell.  The end product of the PEM fuel cell was able to support the auxiliary systems of the truck using a maximum of 5kW of power. This input was able to sustain the cooling chamber, cabin air-conditioning, radio unit, etc. The introduction of this fuel cell also contributed to a 9% reduction in diesel fuel consumption and 9.6% reduction in emissions.", "section_idx": 2, "section_name": "Uses/Implementations", "target_page_ids": [ 46238, 7221088 ], "anchor_spans": [ [ 322, 335 ], [ 954, 970 ] ] }, { "plaintext": "The United States Environmental Protection Agency has set out rules and guidelines for how auxiliary and supplemental power sources (ASPS) that provide secondary power to wastewater treatment plants in case of a blackout.  ASPS should be able to supply enough power to run the plant effectively, and be available for start-up in a short period of time in case of emergency. Types of ASPS necessary for adequate power generation include: internal combustion engines, microturbines, solar cells, fuel cells, and wind turbines.  ASPS technology is required to be reliable enough to start up quickly, and run for extended periods of time, (i.e. 48 hours or more) with sufficient fuel.", "section_idx": 3, "section_name": "Legal Requirements for Industries", "target_page_ids": [ 58664, 2352910, 11729, 20541773 ], "anchor_spans": [ [ 467, 480 ], [ 482, 492 ], [ 495, 504 ], [ 511, 523 ] ] }, { "plaintext": "As previously affirmed, auxiliary power units are commonly used to improve the efficiency of electrical system. The use of auxiliary power units for range extended electric automobiles has been shown to improve the control of energy flow and distribution throughout the system, improving its overall efficiency.", "section_idx": 4, "section_name": "Efficiency", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "For closed systems with extreme power consumption such as tankers and other vessels at sea, the use and quality of auxiliary power systems have a great impact on the efficiency of the overall system.  The different uses of auxiliary power for an array of ships and ship activities and how these different power schemes change the overall efficiency and/emissions of the ship's system. Studies have indicated that while ships travel between ports within the same bay, total ship exhaust emissions are due to primarily their auxiliary boiler and auxiliary engine power systems, due to the time and speed required to transit the port waters with the large berth of the vessel.  Findings also lead to the conclusion that the power output capabilities of auxiliary engines at a certain point do not increase with the size of the vessel, or the vessel's installed main engine power. There are a great many factors such as machinery variables, power schemes, and size and power of vessels, that there are too many factors to take into account in order to portray an accurate representation of the ratio between main power and auxiliary power output. More surveys and studies should be done in order to achieve this more accurate result.", "section_idx": 4, "section_name": "Efficiency", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "distributed generation", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 245963 ], "anchor_spans": [ [ 0, 22 ] ] }, { "plaintext": "Federal Standard 1037C and MIL-STD-180f.", "section_idx": 6, "section_name": "References", "target_page_ids": [ 37310 ], "anchor_spans": [ [ 0, 22 ] ] } ]

[ "Electric_power" ]

[]

[ { "plaintext": "In reliability engineering, the term availability has the following meanings:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 1724836 ], "anchor_spans": [ [ 3, 26 ] ] }, { "plaintext": " The degree to which a system, subsystem or equipment is in a specified operable and committable state at the start of a mission, when the mission is called for at an unknown, i.e. a random, time.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 8286675, 8286675 ], "anchor_spans": [ [ 23, 29 ], [ 31, 40 ] ] }, { "plaintext": " The probability that an item will operate satisfactorily at a given point in time when used under stated conditions in an ideal support environment.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Normally high availability systems might be specified as 99.98%, 99.999% or 99.9996%.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The simplest representation of availability (A) is a ratio of the expected value of the uptime of a system to the aggregate of the expected values of up and down time (that results in the \"total amont of time\" C of the observation window)", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Another equation for availability (A) is a ratio of the Mean Time To Failure (MTTF) and Mean Time To Repair (MTTR), or", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "If we define the status function as", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "therefore, the availability A(t) at time t>0 is represented by", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Average availability must be defined on an interval of the real line. If we consider an arbitrary constant , then average availability is represented as", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Limiting (or steady-state) availability is represented by", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Limiting average availability is also defined on an interval as,", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Availability is the probability that an item will be in an operable and committable state at the start of a mission when the mission is called for at a random time, and is generally defined as uptime divided by total time (uptime plus downtime).", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Reliability Block Diagrams or Fault Tree Analysis are developed to calculate availability of a system or a functional failure condition within a system including many factors like:", "section_idx": 1, "section_name": "Representation", "target_page_ids": [ 26255087, 70526 ], "anchor_spans": [ [ 0, 26 ], [ 30, 49 ] ] }, { "plaintext": " Reliability models", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Maintainability models", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Maintenance concepts", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Redundancy", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Common cause failure", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Diagnostics", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Level of repair", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Repair status", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Dormant failures", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Test coverage", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Active operational times / missions / sub system states", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Logistical aspects like; spare part (stocking) levels at different depots, transport times, repair times at different repair lines, manpower availability and more.", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Uncertainty in parameters", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Furthermore, these methods are capable to identify the most critical items and failure modes or events that impact availability.", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Availability, inherent (Ai) ", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The probability that an item will operate satisfactorily at a given point in time when used under stated conditions in an ideal support environment. It excludes logistics time, waiting or administrative downtime, and preventive maintenance downtime. It includes corrective maintenance downtime. ", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Inherent availability is generally derived from analysis of an engineering design:", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " The impact of a repairable-element (refurbishing/remanufacture isn't repair, but rather replacement) on the availability of the system, in which it operates, equals mean time between failures MTBF/(MTBF+ mean time to repair MTTR).", "section_idx": 1, "section_name": "Representation", "target_page_ids": [ 63397, 2503691 ], "anchor_spans": [ [ 166, 192 ], [ 205, 224 ] ] }, { "plaintext": " The impact of a one-off/non-repairable element (could be refurbished/remanufactured) on the availability of the system, in which it operates, equals the mean time to failure (MTTF)/(MTTF + the mean time to repair MTTR).", "section_idx": 1, "section_name": "Representation", "target_page_ids": [ 63397, 2503691 ], "anchor_spans": [ [ 154, 174 ], [ 194, 213 ] ] }, { "plaintext": "It is based on quantities under control of the designer.", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Availability, achieved (Aa) ", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The probability that an item will operate satisfactorily at a given ", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "point in time when used under stated conditions in an ideal support environment (i.e., that personnel, tools, spares, etc. are instantaneously available). It excludes logistics time and waiting or administrative downtime. ", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "It includes active preventive and corrective maintenance downtime.", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Availability, operational (Ao) ", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The probability that an item will operate satisfactorily at a given point in time when used in an actual or realistic operating and support environment. It includes logistics time, ready time, and waiting or administrative downtime, and both preventive and corrective maintenance downtime. This value is equal to the mean time between failure (MTBF) divided by the mean time between failure plus the mean downtime (MDT). This measure extends the definition of availability to elements controlled by the logisticians and mission planners such as quantity and proximity of spares, tools and manpower to the hardware item.", "section_idx": 1, "section_name": "Representation", "target_page_ids": [ 63397 ], "anchor_spans": [ [ 344, 348 ] ] }, { "plaintext": "Refer to Systems engineering for more details", "section_idx": 1, "section_name": "Representation", "target_page_ids": [ 27764 ], "anchor_spans": [ [ 9, 28 ] ] }, { "plaintext": "If we are using equipment which has a mean time to failure (MTTF) of 81.5 years and mean time to repair (MTTR) of 1 hour:", "section_idx": 1, "section_name": "Representation", "target_page_ids": [ 63397, 2503691 ], "anchor_spans": [ [ 38, 58 ], [ 84, 103 ] ] }, { "plaintext": " MTTF in hours = (This is a reliability parameter and often has a high level of uncertainty!)", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Inherent availability (Ai) ", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Inherent unavailability ", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Outage due to equipment in hours per year = 1/rate = 1/MTTF = 0.01235 hours per year.", "section_idx": 1, "section_name": "Representation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Availability is well established in the literature of stochastic modeling and optimal maintenance. Barlow and Proschan [1975] define availability of a repairable system as \"the probability that the system is operating at a specified time t.\" Blanchard [1998] gives a qualitative definition of availability as \"a measure of the degree of a system which is in the operable and committable state at the start of mission when the mission is called for at an unknown random point in time.\" This definition comes from the MIL-STD-721. Lie, Hwang, and Tillman [1977] developed a complete survey along with a systematic classification of availability.", "section_idx": 2, "section_name": "Literature", "target_page_ids": [ 4074422, 2777780 ], "anchor_spans": [ [ 54, 73 ], [ 78, 97 ] ] }, { "plaintext": "Availability measures are classified by either the time interval of interest or the mechanisms for the system downtime. If the time interval of interest is the primary concern, we consider instantaneous, limiting, average, and limiting average availability. The aforementioned definitions are developed in Barlow and Proschan [1975], Lie, Hwang, and Tillman [1977], and Nachlas [1998]. The second primary classification for availability is contingent on the various mechanisms for downtime such as the inherent availability, achieved availability, and operational availability. (Blanchard [1998], Lie, Hwang, and Tillman [1977]). Mi [1998] gives some comparison results of availability considering inherent availability.", "section_idx": 2, "section_name": "Literature", "target_page_ids": [ 8008410 ], "anchor_spans": [ [ 110, 118 ] ] }, { "plaintext": "Availability considered in maintenance modeling can be found in Barlow and Proschan [1975] for replacement models, Fawzi and Hawkes [1991] for an R-out-of-N system with spares and repairs, Fawzi and Hawkes [1990] for a series system with replacement and repair, Iyer [1992] for imperfect repair models, Murdock [1995] for age replacement preventive maintenance models, Nachlas [1998, 1989] for preventive maintenance models, and Wang and Pham [1996] for imperfect maintenance models. A very comprehensive recent book is by Trivedi and Bobbio [2017].", "section_idx": 2, "section_name": "Literature", "target_page_ids": [ 28385525 ], "anchor_spans": [ [ 169, 174 ] ] }, { "plaintext": "Availability is used extensively in power plant engineering. For example, the North American Electric Reliability Corporation implemented the Generating Availability Data System in 1982.", "section_idx": 3, "section_name": "Applications", "target_page_ids": [ 212141, 56995, 21347660 ], "anchor_spans": [ [ 36, 59 ], [ 78, 125 ], [ 142, 177 ] ] }, { "plaintext": " Reliability engineering", "section_idx": 4, "section_name": "See also", "target_page_ids": [ 1724836 ], "anchor_spans": [ [ 1, 24 ] ] }, { "plaintext": " Safety engineering", "section_idx": 4, "section_name": "See also", "target_page_ids": [ 29278 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": " List of system quality attributes", "section_idx": 4, "section_name": "See also", "target_page_ids": [ 1081685 ], "anchor_spans": [ [ 1, 34 ] ] }, { "plaintext": " Spurious trip level", "section_idx": 4, "section_name": "See also", "target_page_ids": [ 18580071 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " Condition-based maintenance", "section_idx": 4, "section_name": "See also", "target_page_ids": [ 91191 ], "anchor_spans": [ [ 1, 28 ] ] }, { "plaintext": " Fault reporting", "section_idx": 4, "section_name": "See also", "target_page_ids": [ 36726699 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " High availability", "section_idx": 4, "section_name": "See also", "target_page_ids": [ 3824661 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " RAMS", "section_idx": 4, "section_name": "See also", "target_page_ids": [ 26789010 ], "anchor_spans": [ [ 1, 5 ] ] }, { "plaintext": " K. Trivedi and A. Bobbio, Reliability and Availability Engineering: Modeling, Analysis and Applications, Cambridge University Press, 2017.", "section_idx": 6, "section_name": "Sources", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Reliability and Availability Basics", "section_idx": 7, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " System Reliability and Availability", "section_idx": 7, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Availability and the Different Ways to Calculate It", "section_idx": 7, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " How to track and improve Technical Availability?", "section_idx": 7, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] } ]

[ "Telecommunication_theory" ]

[]

[ { "plaintext": "The backbone is the vertebral column of a vertebrate.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33607453 ], "anchor_spans": [ [ 20, 36 ] ] }, { "plaintext": " Backbone (1923 film), a 1923 lost silent film starring Alfred Lunt", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 41170298 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Backbone (1975 film), a 1975 Yugoslavian drama directed by Vlatko Gilić", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 22753349 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Backbones (album), a 2004 Wishbone Ash compilation album", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 20152966 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Backbone (Backbone album), 1998", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 25829223 ], "anchor_spans": [ [ 1, 26 ] ] }, { "plaintext": " Backbone (Boney James album), 1993", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 30030695 ], "anchor_spans": [ [ 1, 29 ] ] }, { "plaintext": " Backbone (Roam album), 2016", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 49193746 ], "anchor_spans": [ [ 1, 22 ] ] }, { "plaintext": " Backbone (Anthony Callea album), 2016", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 51330424 ], "anchor_spans": [ [ 1, 32 ] ] }, { "plaintext": " Backbone (Status Quo album), 2019", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 61305188 ], "anchor_spans": [ [ 1, 28 ] ] }, { "plaintext": " \"At the End of the Day / Backbone\", 1993 song by Baby Animals", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 51501087 ], "anchor_spans": [ [ 2, 34 ] ] }, { "plaintext": " \"Backbone\", 2005 song by Gojira from the album From Mars to Sirius", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 4540556 ], "anchor_spans": [ [ 48, 67 ] ] }, { "plaintext": " \"Backbone\" (Daughtry song), 2018 song by American rock band Daughtry", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 57614408 ], "anchor_spans": [ [ 1, 27 ] ] }, { "plaintext": " Backbone, a rock band led by former Grateful Dead drummer Bill Kreutzmann", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 390939 ], "anchor_spans": [ [ 59, 74 ] ] }, { "plaintext": " Backbone (solitaire), a solitaire game", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 40890886 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Backbone (magazine), a Canadian business magazine", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 23804516 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " Backbone One (gaming device), a hardware and software platform", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 67401016 ], "anchor_spans": [ [ 1, 29 ] ] }, { "plaintext": " Backbone (video game), a 2021 indie video game", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 68635148 ], "anchor_spans": [ [ 2, 23 ] ] }, { "plaintext": " Backbone Entertainment, a video game development company", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 3128849 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": " Backbone, Virginia, US", "section_idx": 2, "section_name": "Places", "target_page_ids": [ 18395712 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": " European backbone, or \"Blue Banana\", a geographic corridor of urbanisation in Western Europe ", "section_idx": 2, "section_name": "Places", "target_page_ids": [ 7183276 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Backbone State Park, oldest state park in Iowa, US", "section_idx": 2, "section_name": "Places", "target_page_ids": [ 11678315 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " Backbone chain, in polymer chemistry, the framework of the molecule", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 308865 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Backbone network, the top level of a hierarchical computer network", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 2853516 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Internet backbone, principal data routes between interconnected networks and core routers in the Internet", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 48402 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Backbone.js, a JavaScript library used to build applications", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 33678253 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Backbone (British radio communications network)", "section_idx": 4, "section_name": "Other uses", "target_page_ids": [ 8627711 ], "anchor_spans": [ [ 1, 48 ] ] } ]

[]

[]

[ { "plaintext": "A back-to-back connection is the direct connection of the output of one device to the input of a similar or related device.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 152654 ], "anchor_spans": [ [ 40, 50 ] ] }, { "plaintext": "In telecommunications, a back-to-back connection can be formed by connecting a transmitter directly to a receiver without a transmission line in between. This is used for equipment measurements and testing purposes. The back-to-back connection eliminates the effects of the transmission medium.", "section_idx": 1, "section_name": "Telecommunications", "target_page_ids": [ 33094374, 61164, 41811, 41812 ], "anchor_spans": [ [ 3, 20 ], [ 79, 90 ], [ 124, 141 ], [ 274, 293 ] ] }, { "plaintext": "In some cases, the output of a receiving device is instead connected to the input of a transmitting device.", "section_idx": 1, "section_name": "Telecommunications", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "A back-to-back connection for electric power transmission is a high-voltage direct-current (HVDC) system with both ends in the same switchyard. This is used to couple asynchronously operated power grids or for connecting power grids of different frequencies where no DC transmission line is necessary.", "section_idx": 2, "section_name": "Power transmission", "target_page_ids": [ 38824, 47716, 320217, 20344155, 10779 ], "anchor_spans": [ [ 30, 57 ], [ 63, 90 ], [ 132, 142 ], [ 191, 201 ], [ 246, 257 ] ] }, { "plaintext": "In electronics, a back-to-back connection is the connection of two identical or similar components in series with the opposite polarity. This is used to convert polarised components to non-polar use. Common examples include:", "section_idx": 3, "section_name": "Electronics", "target_page_ids": [ 9663, 270770 ], "anchor_spans": [ [ 3, 14 ], [ 102, 108 ] ] }, { "plaintext": " electrolytic capacitors", "section_idx": 3, "section_name": "Electronics", "target_page_ids": [ 343492 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": " zener diodes", "section_idx": 3, "section_name": "Electronics", "target_page_ids": [ 97835 ], "anchor_spans": [ [ 1, 12 ] ] } ]

[ "Telecommunications_techniques", "High-voltage_direct_current", "Capacitors", "Diodes" ]

[]

[ { "plaintext": "In a data transmission circuit a backward channel is the channel that passes data in a direction opposite to that of its associated forward channel. The backward channel is usually used for transmission of request, supervisory, acknowledgement, or error-control signals. The direction of flow of these signals is opposite to that in which user information is being transferred. The backward-channel bandwidth is usually less than that of the primary channel, that is, the forward (user information) channel. For example, ADSL's upstream channel, considered a backward channel for some types of analysis, typically has a bandwidth less than one-fourth of the downstream channel.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 40999, 156700, 29145018, 41118, 53229, 15612827, 53229, 18934536 ], "anchor_spans": [ [ 5, 30 ], [ 140, 147 ], [ 229, 244 ], [ 249, 254 ], [ 340, 356 ], [ 401, 410 ], [ 483, 499 ], [ 524, 528 ] ] }, { "plaintext": "In data transmission, it is a secondary channel in which the direction of transmission is constrained to be opposite to that of the primary, i.e., the forward (user-information) channel. The direction of transmission in the backward channel is restricted by the control interchange circuit that controls the direction of transmission in the primary channel.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 42168, 41272, 41577 ], "anchor_spans": [ [ 3, 20 ], [ 271, 290 ], [ 342, 357 ] ] }, { "plaintext": " Return channel", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 2621372 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": "Federal Standard 1037C", "section_idx": 2, "section_name": "References", "target_page_ids": [ 37310 ], "anchor_spans": [ [ 0, 22 ] ] }, { "plaintext": "MIL-STD-188", "section_idx": 2, "section_name": "References", "target_page_ids": [ 41882 ], "anchor_spans": [ [ 0, 11 ] ] } ]

[ "Data_transmission" ]

[]

[ { "plaintext": "In telecommunications and professional audio, a balanced line or balanced signal pair is a circuit consisting of two conductors of the same type, both of which have equal impedances along their lengths and equal impedances to ground and to other circuits. The chief advantage of the balanced line format is good rejection of common-mode noise and interference when fed to a differential device such as a transformer or differential amplifier. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 4037385, 41957, 41215, 30906, 326647 ], "anchor_spans": [ [ 3, 20 ], [ 26, 44 ], [ 171, 181 ], [ 226, 232 ], [ 404, 415 ], [ 419, 441 ] ] }, { "plaintext": "As prevalent in sound recording and reproduction, balanced lines are referred to as balanced audio. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 2417230, 258958 ], "anchor_spans": [ [ 16, 31 ], [ 84, 98 ] ] }, { "plaintext": "Common forms of balanced line are twin-lead, used for radio frequency signals and twisted pair, used for lower frequencies. They are to be contrasted to unbalanced lines, such as coaxial cable, which is designed to have its return conductor connected to ground, or circuits whose return conductor actually is ground (see earth-return telegraph). Balanced and unbalanced circuits can be interfaced using a device called a balun.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 321524, 80506, 2803396, 46380, 41215, 63657523, 10956197, 48160061, 296399 ], "anchor_spans": [ [ 34, 43 ], [ 82, 94 ], [ 153, 168 ], [ 179, 192 ], [ 254, 260 ], [ 321, 343 ], [ 346, 354 ], [ 359, 377 ], [ 421, 426 ] ] }, { "plaintext": "Circuits driving balanced lines must themselves be balanced to maintain the benefits of balance. This may be achieved by transformer coupling (repeating coils) or by merely balancing the impedance in each conductor.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 41656 ], "anchor_spans": [ [ 143, 157 ] ] }, { "plaintext": "Lines carrying symmetric signals (those with equal amplitudes but opposite polarities on each leg) are often incorrectly referred to as \"balanced\", but this is actually differential signaling. Balanced lines and differential signaling are often used together, but they are not the same thing. Differential signaling does not make a line balanced, nor does noise rejection in balanced cables require differential signaling.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 1423256 ], "anchor_spans": [ [ 169, 191 ] ] }, { "plaintext": "Transmission of a signal over a balanced line reduces the influence of noise or interference due to external stray electric fields. Any external signal sources tend to induce only a common mode signal on the line, and the balanced impedances to ground minimizes differential pickup due to stray electric fields. The conductors are sometimes twisted together to ensure that each conductor is equally exposed to any external magnetic fields that could induce unwanted noise.", "section_idx": 1, "section_name": "Explanation", "target_page_ids": [ 742288, 15199671, 41957, 80506 ], "anchor_spans": [ [ 168, 174 ], [ 182, 200 ], [ 231, 240 ], [ 341, 357 ] ] }, { "plaintext": "Some balanced lines also have electrostatic shielding to reduce the amount of noise introduced. The cable is often wrapped in foil, copper wire, or a copper braid. This shield provides immunity to RF interference but does not provide immunity to magnetic fields.", "section_idx": 1, "section_name": "Explanation", "target_page_ids": [ 151590 ], "anchor_spans": [ [ 30, 53 ] ] }, { "plaintext": "Some balanced lines use 4-conductor star quad cable to provide immunity to magnetic fields. The geometry of the cable ensures that magnetic fields will cause equal interference of both legs of the balanced circuit. This balanced interference is a common-mode signal that can easily be removed by a transformer or balanced differential receiver.", "section_idx": 1, "section_name": "Explanation", "target_page_ids": [ 49451315 ], "anchor_spans": [ [ 36, 51 ] ] }, { "plaintext": "A balanced line allows a differential receiver to reduce the noise on a connection by rejecting common-mode interference. The lines have the same impedance to ground, so the interfering fields or currents induce the same voltage in both wires. Since the receiver responds only to the difference between the wires, it is not influenced by the induced noise voltage. If a balanced line is used in an unbalanced circuit, with different impedances from each conductor to ground, currents induced in the separate conductors will cause different voltage drops to ground, thus creating a voltage differential, making the line more susceptible to noise. Examples of twisted pairs include category 5 cable.", "section_idx": 1, "section_name": "Explanation", "target_page_ids": [ 1423256, 41415, 15199671, 41957, 51538 ], "anchor_spans": [ [ 25, 46 ], [ 61, 66 ], [ 96, 120 ], [ 146, 155 ], [ 680, 696 ] ] }, { "plaintext": "Compared to unbalanced lines, balanced lines reduce the amount of noise per distance, allowing a longer cable run to be practical. This is because electromagnetic interference will affect both signals the same way. Similarities between the two signals are automatically removed at the end of the transmission path when one signal is subtracted from the other.", "section_idx": 1, "section_name": "Explanation", "target_page_ids": [ 2803396 ], "anchor_spans": [ [ 12, 28 ] ] }, { "plaintext": "The first application for balanced lines was for telephone lines. Interference that was of little consequence on a telegraph system (which is in essence digital) could be very disturbing for a telephone user. The initial format was to take two single-wire unbalanced telegraph lines and use them as a pair. This proved insufficient, however, with the growth of electric power transmission which tended to use the same routes. A telephone line running alongside a power line for many miles will inevitably have more interference induced in one leg than the other since one of them will be nearer to the power line. This issue was addressed by swapping the positions of the two legs every few hundred yards with a cross-over, thus ensuring that both legs had equal interference induced and allowing common-mode rejection to do its work. As the telephone system grew, it became preferable to use cable rather than open wires to save space, and also to avoid poor performance during bad weather. The cable construction used for balanced telephone cables was twisted pair; however, this did not become widespread until repeater amplifiers became available. For an unamplified telephone line, a twisted pair cable could only manage a maximum distance of 30km. Open wires, on the other hand, with their lower capacitance, had been used for enormous distances—the longest was the 1500km from New York to Chicago built in 1893. Loading coils were used to improve the distance achievable with cable but the problem was not finally overcome until amplifiers started to be installed in 1912. Twisted pair balanced lines are still widely used for local loops, the lines that connect each subscriber's premises to their respective exchange.", "section_idx": 2, "section_name": "Telephone systems", "target_page_ids": [ 80506, 41326, 59602, 26668156 ], "anchor_spans": [ [ 1054, 1066 ], [ 1419, 1432 ], [ 1634, 1644 ], [ 1717, 1725 ] ] }, { "plaintext": "Telephone trunk lines, and especially frequency division multiplexing carrier systems, are usually 4-wire circuits rather than 2-wire circuits (or at least they were before fibre-optic became widespread) and require a different kind of cable. This format requires the conductors to be arranged in two pairs, one pair for the sending (go) signal and the other for the return signal. The greatest source of interference on this kind of transmission is usually the crosstalk between the go and return circuits themselves. The most common cable format is star quad, where the diagonally opposite conductors form the pairs. This geometry gives maximum common mode rejection between the two pairs. An alternative format is DM (Dieselhorst-Martin) quad which consists of two twisted pairs with the twisting at different pitches.", "section_idx": 2, "section_name": "Telephone systems", "target_page_ids": [ 593233, 86376, 3372377, 41811 ], "anchor_spans": [ [ 10, 20 ], [ 38, 69 ], [ 173, 184 ], [ 551, 560 ] ] }, { "plaintext": "An example of balanced lines is the connection of microphones to a mixer in professional systems. Classically, both dynamic and condenser microphones used transformers to provide a differential-mode signal. While transformers are still used in the large majority of modern dynamic microphones, more recent condenser microphones are more likely to use electronic drive circuitry. Each leg, irrespective of any signal, should have an identical impedance to ground. Pair cable (or a pair-derivative such as star quad) is used to maintain the balanced impedances and close twisting of the cores ensures that any interference is common to both conductors. Providing that the receiving end (usually a mixing console) does not disturb the line balance, and is able to ignore common-mode (noise) signals, and can extract differential ones, then the system will have excellent immunity to induced interference.", "section_idx": 3, "section_name": "Audio systems", "target_page_ids": [ 65886, 30906, 49451315, 193299 ], "anchor_spans": [ [ 50, 60 ], [ 155, 166 ], [ 504, 513 ], [ 695, 709 ] ] }, { "plaintext": "Typical professional audio sources, such as microphones, have three-pin XLR connectors. One connects to the shield or chassis ground, while the other two are for the signal conductors. The signal wires can carry two copies of the same signal with opposite polarity (differential signalling) but need not do so. They are often termed \"hot\" and \"cold,\" and the AES14-1992(r2004) Standard [and EIA Standard RS-297-A] suggest that the pin that carries the positive signal that results from a positive air pressure on a transducer will be deemed 'hot'. Pin 2 has been designated as the 'hot' pin, and that designation serves useful for keeping a consistent polarity in the rest of the system. Since these conductors travel the same path from source to destination, the assumption is that any interference is induced upon both conductors equally. The appliance receiving the signals compares the difference between the two signals (often with disregard to electrical ground) allowing the appliance to ignore any induced electrical noise. Any induced noise would be present in equal amounts and in identical polarity on each of the balanced signal conductors, so the two signals’ difference from each other would be unchanged. The successful rejection of induced noise from the desired signal depends in part on the balanced signal conductors receiving the same amount and type of interference. This typically leads to twisted, braided, or co-jacketed cables for use in balanced signal transmission.", "section_idx": 3, "section_name": "Audio systems", "target_page_ids": [ 320466, 1423256 ], "anchor_spans": [ [ 72, 85 ], [ 266, 289 ] ] }, { "plaintext": "Many explanations of balanced lines assume symmetric signals (i.e. signals equal in magnitude but of opposite polarity) but this can lead to confusion of the two concepts—signal symmetry and balanced lines are quite independent of each other. Essential in a balanced line is identical impedances in the two conductors in the driver, line and receiver (impedance balancing). These conditions ensure that external noise affects each leg of the line equally and thus appears as a common mode signal that is rejected by the receiver. There are balanced drive circuits that have excellent common-mode impedance balancing between the legs but do not provide symmetric signals. Symmetric differential signals concern headroom and are not necessary for interference rejection.", "section_idx": 4, "section_name": "Balanced and differential", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Interfacing balanced and unbalanced lines requires a balun. For example, baluns can be used to send line level audio or E-carrier level 1 signals over coaxial cable (which is unbalanced) through of balanced category 5 cable by using a pair of baluns at each end of the CAT5 run. As the signal travels through the balanced line, noise is induced and added to the signal. As the CAT5 line is carefully impedance balanced, the noise induces equal (common-mode) voltages in both conductors. At the receiving end, the balun responds only to the difference in voltage between the two conductors, thus rejecting the noise picked up along the way and leaving the original signal intact.", "section_idx": 5, "section_name": "Baluns", "target_page_ids": [ 296399, 839321, 46728, 51538 ], "anchor_spans": [ [ 53, 58 ], [ 100, 110 ], [ 120, 137 ], [ 208, 224 ] ] }, { "plaintext": "A once common application of a radio frequency balun was found at the antenna terminals of a television receiver. Typically a 300-ohm balanced twin lead antenna input could only be connected to a coaxial cable from a cable TV system through a balun.", "section_idx": 5, "section_name": "Baluns", "target_page_ids": [ 42852, 29831, 321524 ], "anchor_spans": [ [ 31, 46 ], [ 93, 103 ], [ 143, 152 ] ] }, { "plaintext": "The characteristic impedance of a transmission line is an important parameter at higher frequencies of operation. For a parallel 2-wire transmission line,", "section_idx": 6, "section_name": "Characteristic impedance", "target_page_ids": [ 40866 ], "anchor_spans": [ [ 4, 28 ] ] }, { "plaintext": "where is half the distance between the wire centres, is the wire radius and , are respectively the permeability and permittivity of the surrounding medium. A commonly used approximation that is valid when the wire separation is much larger than the wire radius and in the absence of magnetic materials is", "section_idx": 6, "section_name": "Characteristic impedance", "target_page_ids": [ 754487, 53933 ], "anchor_spans": [ [ 102, 114 ], [ 119, 131 ] ] }, { "plaintext": "where is the relative permittivity of the surrounding medium.", "section_idx": 6, "section_name": "Characteristic impedance", "target_page_ids": [ 53781 ], "anchor_spans": [ [ 14, 35 ] ] }, { "plaintext": "In electric power transmission, the three conductors used for three-phase power transmission are referred to as a balanced line since the instantaneous sum of the three line voltages is nominally zero. However, balance in this field is referring to the symmetry of the source and load: it has nothing to do with the impedance balance of the line itself, the sense of the meaning in telecommunications.", "section_idx": 7, "section_name": "Electric power lines", "target_page_ids": [ 38824, 38829 ], "anchor_spans": [ [ 3, 30 ], [ 62, 79 ] ] }, { "plaintext": "For the transmission of single-phase electric power as used for railway electrification systems, two conductors are used to carry in-phase and out-of-phase voltages such that the line is balanced.", "section_idx": 7, "section_name": "Electric power lines", "target_page_ids": [ 227049, 558959 ], "anchor_spans": [ [ 24, 51 ], [ 64, 94 ] ] }, { "plaintext": "Bipolar HVDC lines at which each pole is operated with the same voltage toward ground are also balanced lines.", "section_idx": 7, "section_name": "Electric power lines", "target_page_ids": [ 47716 ], "anchor_spans": [ [ 0, 12 ] ] }, { "plaintext": " Differential pair", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 8937480 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Twinaxial cabling", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 6526134 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Twisted-pair cable", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 80506 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": " Ethernet over twisted pair", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 35203 ], "anchor_spans": [ [ 1, 27 ] ] }, { "plaintext": " RS-422", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 335376 ], "anchor_spans": [ [ 1, 7 ] ] }, { "plaintext": " RS-485", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 1179248 ], "anchor_spans": [ [ 1, 7 ] ] }, { "plaintext": " Low-voltage differential signalling (LVDS)", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 153998 ], "anchor_spans": [ [ 1, 36 ] ] }, { "plaintext": " Balanced Lines, Phantom Powering, Grounding, and Other Arcane Mysteries from Mackie;", "section_idx": 10, "section_name": "External links", "target_page_ids": [ 1283825 ], "anchor_spans": [ [ 79, 85 ] ] } ]

[ "Communication_circuits" ]

[]

[ { "plaintext": "In telecommunications, balance return loss is one of two things:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374 ], "anchor_spans": [ [ 3, 20 ] ] }, { "plaintext": " A measure of the degree of balance between two impedances connected to two conjugate sides of a hybrid set, coil, network, or junction.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 46545 ], "anchor_spans": [ [ 115, 122 ] ] }, { "plaintext": " A measure of the effectiveness with which a balancing network simulates the impedance of a two-wire circuit at a hybrid coil.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 40769, 41957, 2139185, 41246 ], "anchor_spans": [ [ 45, 62 ], [ 77, 86 ], [ 92, 108 ], [ 114, 125 ] ] } ]

[ "Telecommunication_theory" ]

[]

[ { "plaintext": "In a hybrid set, hybrid coil, or resistance hybrid, balancing network is a circuit used to match, i.e., to balance, the impedance of a uniform transmission line, (e.g., a twisted metallic pair, coaxial cable, etc.) over a selected range of frequencies. A balancing network is required to ensure isolation between the two ports of the four-wire side of the hybrid.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 2437593, 41246, 8707643, 41957 ], "anchor_spans": [ [ 5, 11 ], [ 17, 28 ], [ 75, 82 ], [ 120, 129 ] ] }, { "plaintext": "A balancing network can also be a device used between a balanced device or line and an unbalanced device or line for the purpose of transforming from balanced to unbalanced or from unbalanced to balanced.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Source: from Federal Standard 1037C and from MIL-STD-188", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 37310, 41882 ], "anchor_spans": [ [ 13, 35 ], [ 45, 56 ] ] }, { "plaintext": "balun", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 296399 ], "anchor_spans": [ [ 0, 5 ] ] } ]

[ "Analog_circuits" ]

[]

[ { "plaintext": "In telecommunication, the term bandwidth compression has the following meanings: ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374 ], "anchor_spans": [ [ 3, 20 ] ] }, { "plaintext": "The reduction of the bandwidth needed to transmit a given amount of data in a given time.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 15612827, 18985040, 30012 ], "anchor_spans": [ [ 21, 30 ], [ 68, 72 ], [ 84, 88 ] ] }, { "plaintext": "The reduction of the time needed to transmit a given amount of data in a given bandwidth.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Bandwidth compression implies a reduction in normal bandwidth of an information-carrying signal without reducing the information content of the signal. This can be accomplished with lossless data compression techniques. For more information read the Increasing speeds section in the Modem article. Bandwidth Compression is a core feature of WAN Optimization appliances to improve bandwidth efficiency.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 18985062, 275871, 8013, 20647197, 20647197, 5658266 ], "anchor_spans": [ [ 68, 79 ], [ 89, 95 ], [ 191, 207 ], [ 250, 267 ], [ 283, 288 ], [ 341, 357 ] ] }, { "plaintext": " Federal Standard 1037C ", "section_idx": 1, "section_name": "References", "target_page_ids": [ 37310 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": " MIL-STD-188", "section_idx": 1, "section_name": "References", "target_page_ids": [ 41882 ], "anchor_spans": [ [ 1, 12 ] ] } ]

[ "Telecommunication_theory" ]

[]

[ { "plaintext": "Barrage jamming is an electronic warfare technique that attempts to blind (\"jam\") radar systems by filling the display with noise, rendering the broadcaster's blip invisible on the display, and often those in the nearby area as well. \"Barrage\" refers to systems that send signals in many bands of frequencies compared to the bandwidth of any single radar. This allows the jammer to jam multiple radars at once, and reduces or eliminates the need for adjustments to respond to any single radar.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 82272, 1838237, 25676, 634183, 3967 ], "anchor_spans": [ [ 23, 41 ], [ 77, 80 ], [ 83, 88 ], [ 289, 293 ], [ 326, 335 ] ] }, { "plaintext": "Early radar systems typically operated on a single frequency, and could only change that frequency by changing internal electronics. Against these radars, it was possible to use conventional radio sets to send out signals on the same band, causing the radar display to be filled with noise whenever the antenna was pointed in the general direction of the jammer. However, given that each individual radar would be operating on different frequencies, this \"spot jamming\" technique required multiple radio sets in order to jam more than one radar at a time, and true wide-band barrage jamming was very difficult.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Early barrage jammers in World War II used photomultiplier tubes to amplify a wideband noise source, But the technique became practical with the introduction of the carcinotron in the early 1950s, a vacuum tube that generates microwaves whose frequency can be adjusted across a very wide band simply by changing the input voltage. A single carcinotron could be swept through the entire bandwidth of any potential radar network, jamming all of the radars in such rapid sequence that it appeared to be constant noise on all frequencies at all times. A downside to this approach is that the signal only spends a brief period of time at any one radar's frequency; depending on the scanning rate, the radar may only be jammed during certain periods, but if the rate is increased to offset this, the amount of noise in any one pulse period is reduced. More complex jammers can scan only the bands it sees being used, improving its effectiveness.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 32927, 60088733, 3057518, 32496, 20097 ], "anchor_spans": [ [ 25, 37 ], [ 43, 58 ], [ 165, 176 ], [ 199, 210 ], [ 226, 235 ] ] }, { "plaintext": "Barrage jamming was extremely effective against 1950s radars, to the point where there was some belief that the carcinotron might render ground-based radars useless, especially in the early warning radar role. By the 1960s a number of techniques had been introduced to combat barrage jamming. Frequency agile radars, which change their frequency from pulse to pulse, force the jammer spread its signal across the entire bandwidth, ensuring the signal is diluted. Combining this with extremely powerful signals and highly focused antennas allowed new radars to overpower the jammers, \"burning through\" the jamming. Simple techniques, like turning off the receivers when the antenna was pointed close to the jammer, allowed the radar to continue tracking other targets. The use of phased array antennas and signal processing techniques that reduced sidelobes also improved performance.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 4242881, 22984933, 41509 ], "anchor_spans": [ [ 184, 203 ], [ 293, 308 ], [ 779, 791 ] ] }, { "plaintext": "Barrage jammers also have the disadvantage that they are very easy to detect using a wideband receiver. This can be used to track the jammer using a variety of techniques. A well developed instance of this was deployed by the RAF in their RX12874 network, which could track jammer-carrying aircraft with accuracy equal to a radar. More generally, a barrage jammer's signal is so easy to receive that it makes an excellent early warning signal on its own.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 25679, 58167523 ], "anchor_spans": [ [ 226, 229 ], [ 239, 246 ] ] }, { "plaintext": "Radio jamming", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 1838227 ], "anchor_spans": [ [ 0, 13 ] ] } ]

[ "Electronic_countermeasures" ]

[]

[ { "plaintext": "In telecommunications and signal processing, baseband is the range of frequencies occupied by a signal that has not been modulated to higher frequencies. Baseband signals typically originate from transducers, converting some other variable into an electrical signal. For example, the output of a microphone is a baseband signal that is an analog of the applied voice audio. In conventional analog radio broadcasting the baseband audio signal is used to modulate an RF carrier signal at a much higher frequency.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 29324, 275871, 20637, 242666, 993, 173088, 20637, 42852 ], "anchor_spans": [ [ 3, 20 ], [ 26, 43 ], [ 96, 102 ], [ 121, 130 ], [ 196, 206 ], [ 340, 346 ], [ 398, 416 ], [ 454, 462 ], [ 466, 483 ] ] }, { "plaintext": "A baseband signal may have frequency components going all the way down to DC, or at least it will have a high ratio bandwidth. A modulated baseband signal is called a passband signal. This occupies a higher range of frequencies and has a lower ratio and fractional bandwidth.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 3967, 41488, 3967 ], "anchor_spans": [ [ 110, 125 ], [ 168, 183 ], [ 256, 276 ] ] }, { "plaintext": "A baseband signal or lowpass signal is a signal that can include frequencies that are very near zero, by comparison with its highest frequency (for example, a sound waveform can be considered as a baseband signal, whereas a radio signal or any other modulated signal is not).", "section_idx": 1, "section_name": "Various uses", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "A baseband bandwidth is equal to the highest frequency of a signal or system, or an upper bound on such frequencies, for example the upper cut-off frequency of a low-pass filter. By contrast, passband bandwidth is the difference between a highest frequency and a nonzero lowest frequency.", "section_idx": 1, "section_name": "Various uses", "target_page_ids": [ 3967, 40986, 56484 ], "anchor_spans": [ [ 11, 20 ], [ 139, 156 ], [ 162, 177 ] ] }, { "plaintext": "A baseband channel or lowpass channel (or system, or network) is a communication channel that can transfer frequencies that are very near zero. Examples are serial cables and local area networks (LANs), as opposed to passband channels such as radio frequency channels and passband filtered wires of the analog telephone network. Frequency division multiplexing (FDM) allows an analog telephone wire to carry a baseband telephone call, concurrently as one or several carrier-modulated telephone calls.", "section_idx": 1, "section_name": "Various uses", "target_page_ids": [ 156700, 17739, 41488, 86376 ], "anchor_spans": [ [ 67, 88 ], [ 175, 193 ], [ 217, 225 ], [ 329, 360 ] ] }, { "plaintext": "Digital baseband transmission, also known as line coding, aims at transferring a digital bit stream over baseband channel, typically an unfiltered wire, contrary to passband transmission, also known as carrier-modulated transmission. Passband transmission makes communication possible over a bandpass filtered channel, such as the telephone network local-loop or a band-limited wireless channel.", "section_idx": 1, "section_name": "Various uses", "target_page_ids": [ 41317, 41488 ], "anchor_spans": [ [ 45, 56 ], [ 165, 173 ] ] }, { "plaintext": "The word \"BASE\" in Ethernet physical layer standards, for example 10BASE5, 100BASE-TX and 1000BASE-SX, implies baseband digital transmission (i.e. that a line code and an unfiltered wire are used).", "section_idx": 1, "section_name": "Various uses", "target_page_ids": [ 5559175, 35201, 64506, 64636, 41317 ], "anchor_spans": [ [ 19, 42 ], [ 66, 73 ], [ 75, 85 ], [ 90, 101 ], [ 154, 163 ] ] }, { "plaintext": "A baseband processor also known as BP or BBP is used to process the down-converted digital signal to retrieve essential data for a wireless digital system. The baseband processing block in GNSS receivers is responsible for providing observable data: that is, code pseudo-ranges and carrier phase measurements, as well as navigation data. ", "section_idx": 1, "section_name": "Various uses", "target_page_ids": [ 31609595, 1515653 ], "anchor_spans": [ [ 2, 20 ], [ 189, 193 ] ] }, { "plaintext": "An equivalent baseband signal or equivalent lowpass signal is—in analog and digital modulation methods for (passband) signals with constant or varying carrier frequency (for example ASK, PSK QAM, and FSK)—a complex valued representation of the modulated physical signal (the so-called passband signal or RF signal). The equivalent baseband signal is where is the inphase signal, the quadrature phase signal, and the imaginary unit. In a digital modulation method, the and signals of each modulation symbol are evident from the constellation diagram. The frequency spectrum of this signal includes negative as well as positive frequencies. The physical passband signal corresponds to ", "section_idx": 1, "section_name": "Various uses", "target_page_ids": [ 153217, 946426, 41551, 25316, 41193, 41488, 42852, 2033635 ], "anchor_spans": [ [ 151, 168 ], [ 182, 185 ], [ 187, 190 ], [ 191, 194 ], [ 200, 203 ], [ 285, 293 ], [ 304, 306 ], [ 533, 554 ] ] }, { "plaintext": "where is the carrier angular frequency in rad/s.", "section_idx": 1, "section_name": "Various uses", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "A signal at baseband is often used to modulate a higher frequency carrier signal in order that it may be transmitted via radio. Modulation results in shifting the signal up to much higher frequencies (radio frequencies, or RF) than it originally spanned. A key consequence of the usual double-sideband amplitude modulation (AM) is that the range of frequencies the signal spans (its spectral bandwidth) is doubled. Thus, the RF bandwidth of a signal (measured from the lowest frequency as opposed to 0Hz) is twice its baseband bandwidth. Steps may be taken to reduce this effect, such as single-sideband modulation. Conversely, some transmission schemes such as frequency modulation use even more bandwidth.", "section_idx": 2, "section_name": "Modulation", "target_page_ids": [ 20637, 153217, 41701, 1140, 3967, 29048, 10835 ], "anchor_spans": [ [ 38, 46 ], [ 66, 80 ], [ 286, 301 ], [ 302, 322 ], [ 392, 401 ], [ 588, 614 ], [ 662, 682 ] ] }, { "plaintext": "The figure below shows AM modulation:", "section_idx": 2, "section_name": "Modulation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Complex envelope", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 950777 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Broadband", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 147184 ], "anchor_spans": [ [ 1, 10 ] ] }, { "plaintext": " In-phase and quadrature components", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 3440178 ], "anchor_spans": [ [ 1, 35 ] ] }, { "plaintext": " Narrowband", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 274798 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " Wideband", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 863794 ], "anchor_spans": [ [ 1, 9 ] ] } ]

[ "Signal_processing" ]

[ "lowpass", "unmodulated", "non-modulated" ]

[ { "plaintext": "In telecommunication, a basic exchange telecommunications radio service (BETRS) is a commercial service that can extend telephone service to rural areas by replacing the local loop with radio communications. In the BETRS, non-government ultra high frequency (UHF) and very high frequency (VHF) common carrier and the private radio service frequencies are shared.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 30003, 160478, 15368428, 33094374, 160501, 69480, 40910 ], "anchor_spans": [ [ 3, 20 ], [ 120, 129 ], [ 176, 180 ], [ 186, 191 ], [ 192, 206 ], [ 237, 257 ], [ 268, 287 ], [ 294, 308 ] ] }, { "plaintext": "Further details by FCC", "section_idx": 1, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] } ]

[ "Telecommunications_standards" ]

[]

[ { "plaintext": "In telecommunication, a basic service element (BSE) is: ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374 ], "anchor_spans": [ [ 3, 20 ] ] }, { "plaintext": " An optional unbundled feature, generally associated with the basic serving arrangement (BSA), that an enhanced-service provider (ESP) may require or find useful in configuring an enhanced service.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 40778, 41112 ], "anchor_spans": [ [ 62, 87 ], [ 180, 196 ] ] }, { "plaintext": " A fundamental (basic) communication network service; an optional network capability associated with a BSA.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 46545 ], "anchor_spans": [ [ 37, 44 ] ] }, { "plaintext": "BSEs constitute optional capabilities to which the customer may subscribe or decline to subscribe.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Basic service element at Telecommunications Industry Association's glossary", "section_idx": 1, "section_name": "References", "target_page_ids": [ 4094802 ], "anchor_spans": [ [ 26, 65 ] ] } ]

[ "Telecommunication_services" ]

[]

[ { "plaintext": "In telecommunication, the term basic serving arrangement (BSA) has the following meanings: ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374 ], "anchor_spans": [ [ 3, 20 ] ] }, { "plaintext": " The fundamental tariffed switching and transmission (and other) services that an operating company must provide to an enhanced service provider (ESP) to connect with its customers through the company network.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 26668156, 609152, 41112, 46545 ], "anchor_spans": [ [ 27, 36 ], [ 41, 53 ], [ 120, 136 ], [ 202, 209 ] ] }, { "plaintext": " In an open-network-architecture context, the fundamental underlying connection of an enhanced service provider (ESP) to and through the operating company's network including an ESP access link, the features and functions associated with that access link at the central office serving the ESP and/or other offices, and the transport (dedicated or switched) within the network that completes the connection from the ESP to the central office serving its customers or to capabilities associated with the customer's complementary network services. Each component may have a number of categories of network characteristics. Within these categories of network characteristics are alternatives from among which the customer must choose. Examples of BSA components are ESP access link, transport and/or usage.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 346001, 810183, 40996, 26668156, 1886820, 46545 ], "anchor_spans": [ [ 69, 79 ], [ 182, 188 ], [ 189, 193 ], [ 262, 276 ], [ 550, 559 ], [ 595, 602 ] ] }, { "plaintext": " Federal Standard 1037C", "section_idx": 1, "section_name": "References", "target_page_ids": [ 37310 ], "anchor_spans": [ [ 1, 23 ] ] } ]

[ "Telecommunications_standards" ]

[]

[ { "plaintext": "In coding theory, the BoseChaudhuriHocquenghem codes (BCH codes) form a class of cyclic error-correcting codes that are constructed using polynomials over a finite field (also called Galois field). BCH codes were invented in 1959 by French mathematician Alexis Hocquenghem, and independently in 1960 by Raj Chandra Bose and D.K. Ray-Chaudhuri. The name BoseChaudhuriHocquenghem (and the acronym BCH) arises from the initials of the inventors' surnames (mistakenly, in the case of Ray-Chaudhuri).", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 321869, 4706825, 4237207, 23000, 11615, 11615, 23349325, 1162266, 18064578 ], "anchor_spans": [ [ 3, 16 ], [ 81, 87 ], [ 88, 110 ], [ 138, 148 ], [ 157, 169 ], [ 183, 195 ], [ 254, 272 ], [ 303, 319 ], [ 324, 342 ] ] }, { "plaintext": "One of the key features of BCH codes is that during code design, there is a precise control over the number of symbol errors correctable by the code. In particular, it is possible to design binary BCH codes that can correct multiple bit errors. Another advantage of BCH codes is the ease with which they can be decoded, namely, via an algebraic method known as syndrome decoding. This simplifies the design of the decoder for these codes, using small low-power electronic hardware.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 19616384, 1940782 ], "anchor_spans": [ [ 335, 344 ], [ 361, 378 ] ] }, { "plaintext": "BCH codes are used in applications such as satellite communications, compact disc players, DVDs, disk drives, USB flash drives, solid-state drives, quantum-resistant cryptography and two-dimensional bar codes.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 6429, 11014498, 8472, 400414, 7366298, 26605226, 60600 ], "anchor_spans": [ [ 69, 81 ], [ 91, 94 ], [ 97, 108 ], [ 110, 125 ], [ 128, 145 ], [ 148, 178 ], [ 183, 208 ] ] }, { "plaintext": "Given a prime number and prime power with positive integers and such that , a primitive narrow-sense BCH code over the finite field (or Galois field) with code length and distance at least is constructed by the following method.", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [ 23666, 1630483, 11615, 1134659 ], "anchor_spans": [ [ 8, 20 ], [ 26, 37 ], [ 123, 135 ], [ 177, 185 ] ] }, { "plaintext": "Let be a primitive element of .", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [ 4771726 ], "anchor_spans": [ [ 10, 27 ] ] }, { "plaintext": "For any positive integer , let be the minimal polynomial with coefficients in of .", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [ 9667106 ], "anchor_spans": [ [ 39, 57 ] ] }, { "plaintext": "The generator polynomial of the BCH code is defined as the least common multiple .", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [ 16259862, 17961 ], "anchor_spans": [ [ 4, 24 ], [ 59, 80 ] ] }, { "plaintext": "It can be seen that is a polynomial with coefficients in and divides .", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Therefore, the polynomial code defined by is a cyclic code.", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Let and (therefore ). We will consider different values of for based on the reducing polynomial , using primitive element . There are fourteen minimum polynomials with coefficients in satisfying", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The minimal polynomials are", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The BCH code with has generator polynomial", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "It has minimal Hamming distance at least 3 and corrects up to one error. Since the generator polynomial is of degree 4, this code has 11 data bits and 4 checksum bits.", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [ 41227 ], "anchor_spans": [ [ 15, 31 ] ] }, { "plaintext": "The BCH code with has generator polynomial", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "It has minimal Hamming distance at least 5 and corrects up to two errors. Since the generator polynomial is of degree 8, this code has 7 data bits and 8 checksum bits.", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The BCH code with has generator polynomial", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "It has minimal Hamming distance at least 7 and corrects up to three errors. Since the generator polynomial is of degree 10, this code has 5 data bits and 10 checksum bits. (This particular generator polynomial has a real-world application, in the format patterns of the QR code.)", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [ 828436 ], "anchor_spans": [ [ 270, 277 ] ] }, { "plaintext": "The BCH code with and higher has generator polynomial", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "This code has minimal Hamming distance 15 and corrects 7 errors. It has 1 data bit and 14 checksum bits. In fact, this code has only two codewords: 000000000000000 and 111111111111111.", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "General BCH codes differ from primitive narrow-sense BCH codes in two respects.", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "First, the requirement that be a primitive element of can be relaxed. By relaxing this requirement, the code length changes from to the order of the element ", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [ 493527 ], "anchor_spans": [ [ 140, 145 ] ] }, { "plaintext": "Second, the consecutive roots of the generator polynomial may run from instead of ", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Definition. Fix a finite field where is a prime power. Choose positive integers such that and is the multiplicative order of modulo ", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [ 344542 ], "anchor_spans": [ [ 108, 128 ] ] }, { "plaintext": "As before, let be a primitive th root of unity in and let be the minimal polynomial over of for all ", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [ 171950, 9667106 ], "anchor_spans": [ [ 21, 47 ], [ 68, 86 ] ] }, { "plaintext": "The generator polynomial of the BCH code is defined as the least common multiple ", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [ 17961 ], "anchor_spans": [ [ 59, 80 ] ] }, { "plaintext": "Note: if as in the simplified definition, then is 1, and the order of modulo is ", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Therefore, the simplified definition is indeed a special case of the general one.", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " A BCH code with is called a narrow-sense BCH code.", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " A BCH code with is called primitive.", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The generator polynomial of a BCH code has coefficients from ", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "In general, a cyclic code over with as the generator polynomial is called a BCH code over ", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The BCH code over and generator polynomial with successive powers of as roots is one type of Reed–Solomon code where the decoder (syndromes) alphabet is the same as the channel (data and generator polynomial) alphabet, all elements of . The other type of Reed Solomon code is an original view Reed Solomon code which is not a BCH code.", "section_idx": 1, "section_name": "Definition and illustration", "target_page_ids": [ 45600, 45600 ], "anchor_spans": [ [ 96, 113 ], [ 283, 314 ] ] }, { "plaintext": "The generator polynomial of a BCH code has degree at most . Moreover, if and , the generator polynomial has degree at most .", "section_idx": 2, "section_name": "Properties", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Each minimal polynomial has degree at most . Therefore, the least common multiple of of them has degree at most . Moreover, if then for all . Therefore, is the least common multiple of at most minimal polynomials for odd indices each of degree at most .", "section_idx": 2, "section_name": "Properties", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "A BCH code has minimal Hamming distance at least .", "section_idx": 2, "section_name": "Properties", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Suppose that is a code word with fewer than non-zero terms. Then", "section_idx": 2, "section_name": "Properties", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Recall that are roots of hence of . This implies that satisfy the following equations, for each :", "section_idx": 2, "section_name": "Properties", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "In matrix form, we have", "section_idx": 2, "section_name": "Properties", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The determinant of this matrix equals", "section_idx": 2, "section_name": "Properties", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The matrix is seen to be a Vandermonde matrix, and its determinant is", "section_idx": 2, "section_name": "Properties", "target_page_ids": [ 348641 ], "anchor_spans": [ [ 28, 46 ] ] }, { "plaintext": "which is non-zero. It therefore follows that hence ", "section_idx": 2, "section_name": "Properties", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "A BCH code is cyclic.", "section_idx": 2, "section_name": "Properties", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "A polynomial code of length is cyclic if and only if its generator polynomial divides Since is the minimal polynomial with roots it suffices to check that each of is a root of This follows immediately from the fact that is, by definition, an th root of unity.", "section_idx": 2, "section_name": "Properties", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Because any polynomial that is a multiple of the generator polynomial is a valid BCH codeword, BCH encoding is merely the process of finding some polynomial that has the generator as a factor.", "section_idx": 3, "section_name": "Encoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The BCH code itself is not prescriptive about the meaning of the coefficients of the polynomial; conceptually, a BCH decoding algorithm's sole concern is to find the valid codeword with the minimal Hamming distance to the received codeword. Therefore, the BCH code may be implemented either as a systematic code or not, depending on how the implementor chooses to embed the message in the encoded polynomial.", "section_idx": 3, "section_name": "Encoding", "target_page_ids": [ 8722775 ], "anchor_spans": [ [ 296, 311 ] ] }, { "plaintext": "The most straightforward way to find a polynomial that is a multiple of the generator is to compute the product of some arbitrary polynomial and the generator. In this case, the arbitrary polynomial can be chosen using the symbols of the message as coefficients.", "section_idx": 3, "section_name": "Encoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "As an example, consider the generator polynomial , chosen for use in the (31, 21) binary BCH code used by POCSAG and others. To encode the 21-bit message {101101110111101111101}, we first represent it as a polynomial over :", "section_idx": 3, "section_name": "Encoding", "target_page_ids": [ 1746894 ], "anchor_spans": [ [ 106, 112 ] ] }, { "plaintext": "Then, compute (also over ):", "section_idx": 3, "section_name": "Encoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Thus, the transmitted codeword is {1100111010010111101011101110101}.", "section_idx": 3, "section_name": "Encoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The receiver can use these bits as coefficients in and, after error-correction to ensure a valid codeword, can recompute ", "section_idx": 3, "section_name": "Encoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "A systematic code is one in which the message appears verbatim somewhere within the codeword. Therefore, systematic BCH encoding involves first embedding the message polynomial within the codeword polynomial, and then adjusting the coefficients of the remaining (non-message) terms to ensure that is divisible by .", "section_idx": 3, "section_name": "Encoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "This encoding method leverages the fact that subtracting the remainder from a dividend results in a multiple of the divisor. Hence, if we take our message polynomial as before and multiply it by (to \"shift\" the message out of the way of the remainder), we can then use Euclidean division of polynomials to yield:", "section_idx": 3, "section_name": "Encoding", "target_page_ids": [ 679987 ], "anchor_spans": [ [ 271, 289 ] ] }, { "plaintext": "Here, we see that is a valid codeword. As is always of degree less than (which is the degree of ), we can safely subtract it from without altering any of the message coefficients, hence we have our as", "section_idx": 3, "section_name": "Encoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Over (i.e. with binary BCH codes), this process is indistinguishable from appending a cyclic redundancy check, and if a systematic binary BCH code is used only for error-detection purposes, we see that BCH codes are just a generalization of the mathematics of cyclic redundancy checks.", "section_idx": 3, "section_name": "Encoding", "target_page_ids": [ 38838, 10972761 ], "anchor_spans": [ [ 87, 110 ], [ 246, 285 ] ] }, { "plaintext": "The advantage to the systematic coding is that the receiver can recover the original message by discarding everything after the first coefficients, after performing error correction.", "section_idx": 3, "section_name": "Encoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "There are many algorithms for decoding BCH codes. The most common ones follow this general outline:", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Calculate the syndromes sj for the received vector ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Determine the number of errors t and the error locator polynomial Λ(x) from the syndromes ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Calculate the roots of the error location polynomial to find the error locations Xi", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Calculate the error values Yi at those error locations ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Correct the errors", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "During some of these steps, the decoding algorithm may determine that the received vector has too many errors and cannot be corrected. For example, if an appropriate value of t is not found, then the correction would fail. In a truncated (not primitive) code, an error location may be out of range. If the received vector has more errors than the code can correct, the decoder may unknowingly produce an apparently valid message that is not the one that was sent.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The received vector is the sum of the correct codeword and an unknown error vector The syndrome values are formed by considering as a polynomial and evaluating it at Thus the syndromes are", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "for to ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Since are the zeros of of which is a multiple, Examining the syndrome values thus isolates the error vector so one can begin to solve for it.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "If there is no error, for all If the syndromes are all zero, then the decoding is done.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "If there are nonzero syndromes, then there are errors. The decoder needs to figure out how many errors and the location of those errors.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "If there is a single error, write this as where is the location of the error and is its magnitude. Then the first two syndromes are", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "so together they allow us to calculate and provide some information about (completely determining it in the case of Reed–Solomon codes).", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "If there are two or more errors,", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "It is not immediately obvious how to begin solving the resulting syndromes for the unknowns and ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The first step is finding, compatible with computed syndromes and with minimal possible locator polynomial:", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Three popular algorithms for this task are:", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Peterson–Gorenstein–Zierler algorithm", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Berlekamp–Massey algorithm", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [ 514832 ], "anchor_spans": [ [ 1, 27 ] ] }, { "plaintext": " Sugiyama Euclidean algorithm", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [ 45600 ], "anchor_spans": [ [ 1, 29 ] ] }, { "plaintext": "Peterson's algorithm is the step 2 of the generalized BCH decoding procedure. Peterson's algorithm is used to calculate the error locator polynomial coefficients of a polynomial", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Now the procedure of the Peterson–Gorenstein–Zierler algorithm. Expect we have at least 2t syndromes sc, …, sc+2t−1. Let v=t.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Now that you have the polynomial, its roots can be found in the form by brute force for example using the Chien search algorithm. The exponential", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [ 3375856 ], "anchor_spans": [ [ 108, 120 ] ] }, { "plaintext": "powers of the primitive element will yield the positions where errors occur in the received word; hence the name 'error locator' polynomial.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The zeros of Λ(x) are α−i1, …, α−iv.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Once the error locations are known, the next step is to determine the error values at those locations. The error values are then used to correct the received values at those locations to recover the original codeword.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "For the case of binary BCH, (with all characters readable) this is trivial; just flip the bits for the received word at these positions, and we have the corrected code word. In the more general case, the error weights can be determined by solving the linear system", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "However, there is a more efficient method known as the Forney algorithm.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [ 32969421 ], "anchor_spans": [ [ 55, 71 ] ] }, { "plaintext": "Let", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "And the error evaluator polynomial", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Finally:", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "where", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Than if syndromes could be explained by an error word, which could be nonzero only on positions , then error values are", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "For narrow-sense BCH codes, c = 1, so the expression simplifies to:", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "It is based on Lagrange interpolation and techniques of generating functions.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [ 217523, 160993 ], "anchor_spans": [ [ 15, 37 ], [ 56, 75 ] ] }, { "plaintext": "Consider and for the sake of simplicity suppose for and for Then", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "We want to compute unknowns and we could simplify the context by removing the terms. This leads to the error evaluator polynomial", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Thanks to we have", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Thanks to (the Lagrange interpolation trick) the sum degenerates to only one summand for ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "To get we just should get rid of the product. We could compute the product directly from already computed roots of but we could use simpler form.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "As formal derivative", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [ 3832917 ], "anchor_spans": [ [ 3, 20 ] ] }, { "plaintext": "we get again only one summand in", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "So finally", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "This formula is advantageous when one computes the formal derivative of form", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "yielding:", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "where", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "An alternate process of finding both the polynomial Λ and the error locator polynomial is based on Yasuo Sugiyama's adaptation of the Extended Euclidean algorithm. Correction of unreadable characters could be incorporated to the algorithm easily as well.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [ 99438 ], "anchor_spans": [ [ 134, 162 ] ] }, { "plaintext": "Let be positions of unreadable characters. One creates polynomial localising these positions ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Set values on unreadable positions to 0 and compute the syndromes.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "As we have already defined for the Forney formula let ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Let us run extended Euclidean algorithm for locating least common divisor of polynomials and ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The goal is not to find the least common divisor, but a polynomial of degree at most and polynomials such that ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Low degree of guarantees, that would satisfy extended (by ) defining conditions for ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Defining and using on the place of in the Fourney formula will give us error values.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The main advantage of the algorithm is that it meanwhile computes required in the Forney formula.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The goal is to find a codeword which differs from the received word minimally as possible on readable positions. When expressing the received word as a sum of nearest codeword and error word, we are trying to find error word with minimal number of non-zeros on readable positions. Syndrom restricts error word by condition", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "We could write these conditions separately or we could create polynomial", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "and compare coefficients near powers to ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Suppose there is unreadable letter on position we could replace set of syndromes by set of syndromes defined by equation Suppose for an error word all restrictions by original set of syndromes hold,", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "than", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "New set of syndromes restricts error vector", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "the same way the original set of syndromes restricted the error vector Except the coordinate where we have an is zero, if For the goal of locating error positions we could change the set of syndromes in the similar way to reflect all unreadable characters. This shortens the set of syndromes by ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "In polynomial formulation, the replacement of syndromes set by syndromes set leads to", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Therefore,", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "After replacement of by , one would require equation for coefficients near powers ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "One could consider looking for error positions from the point of view of eliminating influence of given positions similarly as for unreadable characters. If we found positions such that eliminating their influence leads to obtaining set of syndromes consisting of all zeros, than there exists error vector with errors only on these coordinates.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "If denotes the polynomial eliminating the influence of these coordinates, we obtain", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "In Euclidean algorithm, we try to correct at most errors (on readable positions), because with bigger error count there could be more codewords in the same distance from the received word. Therefore, for we are looking for, the equation must hold for coefficients near powers starting from", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "In Forney formula, could be multiplied by a scalar giving the same result.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "It could happen that the Euclidean algorithm finds of degree higher than having number of different roots equal to its degree, where the Fourney formula would be able to correct errors in all its roots, anyway correcting such many errors could be risky (especially with no other restrictions on received word). Usually after getting of higher degree, we decide not to correct the errors. Correction could fail in the case has roots with higher multiplicity or the number of roots is smaller than its degree. Fail could be detected as well by Forney formula returning error outside the transmitted alphabet.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Using the error values and error location, correct the errors and form a corrected code vector by subtracting error values at error locations.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Consider a BCH code in GF(24) with and . (This is used in QR codes.) Let the message to be transmitted be , or in polynomial notation, ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [ 828436 ], "anchor_spans": [ [ 59, 66 ] ] }, { "plaintext": "The \"checksum\" symbols are calculated by dividing by and taking the remainder, resulting in or . These are appended to the message, so the transmitted codeword is .", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Now, imagine that there are two bit-errors in the transmission, so the received codeword is [ 1 0 1 1 1 0 0 0 1 0 1 0 0 ]. In polynomial notation:", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "In order to correct the errors, first calculate the syndromes. Taking we have and ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Next, apply the Peterson procedure by row-reducing the following augmented matrix.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Due to the zero row, is singular, which is no surprise since only two errors were introduced into the codeword.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "However, the upper-left corner of the matrix is identical to , which gives rise to the solution ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The resulting error locator polynomial is which has zeros at and ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The exponents of correspond to the error locations.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "There is no need to calculate the error values in this example, as the only possible value is 1.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Suppose the same scenario, but the received word has two unreadable characters [ 1 0 ? 1 1 ? 0 0 1 0 1 0 0 ]. We replace the unreadable characters by zeros while creating the polynomial reflecting their positions We compute the syndromes and (Using log notation which is independent on GF(24) isomorphisms. For computation checking we can use the same representation for addition as was used in previous example. Hexadecimal description of the powers of are consecutively 1,2,4,8,3,6,C,B,5,A,7,E,F,D,9 with the addition based on bitwise xor.)", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Let us make syndrome polynomial", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "compute", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Run the extended Euclidean algorithm:", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "We have reached polynomial of degree at most 3, and as", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "we get", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Therefore,", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Let Don't worry that Find by brute force a root of The roots are and (after finding for example we can divide by corresponding monom and the root of resulting monom could be found easily).", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Let", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Let us look for error values using formula", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "where are roots of We get", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Fact, that should not be surprising.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Corrected code is therefore [ 1 0 1 1 0 0 1 0 1 0 0].", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Let us show the algorithm behaviour for the case with small number of errors. Let the received word is [ 1 0 ? 1 1 ? 0 0 0 1 0 1 0 0 ].", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Again, replace the unreadable characters by zeros while creating the polynomial reflecting their positions ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Compute the syndromes and ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Create syndrome polynomial", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Let us run the extended Euclidean algorithm:", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "We have reached polynomial of degree at most 3, and as", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "we get", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Therefore,", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Let Don't worry that The root of is ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Let ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Let us look for error values using formula where are roots of polynomial ", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "We get", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The fact that should not be surprising.", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Corrected code is therefore [ 1 0 1 1 0 0 0 1 0 1 0 0].", "section_idx": 4, "section_name": "Decoding", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Course notes are apparently being redone for 2012: ", "section_idx": 6, "section_name": "References", "target_page_ids": [], "anchor_spans": [] } ]

[ "Error_detection_and_correction", "Finite_fields", "Coding_theory" ]

[ "Bose–Chaudhuri–Hocquenghem codes", "Bose-Chaudhuri-Hocquenghem codes" ]

[ { "plaintext": "The beam diameter or beam width of an electromagnetic beam is the diameter along any specified line that is perpendicular to the beam axis and intersects it. Since beams typically do not have sharp edges, the diameter can be defined in many different ways. Five definitions of the beam width are in common use: D4σ or second-moment width, 10/90 or 20/80 Knife-edge width, 1/e2 width, Full width at half maximum, and D86 width. The beam width can be measured in units of length at a particular plane perpendicular to the beam axis, but it can also refer to the angular width, which is the angle subtended by the beam at the source. The angular width is also called the beam divergence.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 1612888, 40781 ], "anchor_spans": [ [ 38, 58 ], [ 669, 684 ] ] }, { "plaintext": "Beam diameter is usually used to characterize electromagnetic beams in the optical regime, and occasionally in the microwave regime, that is, cases in which the aperture from which the beam emerges is very large with respect to the wavelength.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 20097, 1470583, 33125 ], "anchor_spans": [ [ 115, 124 ], [ 161, 169 ], [ 232, 242 ] ] }, { "plaintext": "Beam diameter usually refers to a beam of circular cross section, but not necessarily so. A beam may, for example, have an elliptical cross section, in which case the orientation of the beam diameter must be specified, for example with respect to the major or minor axis of the elliptical cross section. The term \"beam width\" may be preferred in applications where the beam does not have circular symmetry.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The angle between the maximum peak of radiated power and the first null (no power radiated in this direction) is called the Rayleigh beamwidth.", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The simplest way to define the width of a beam is to choose two diametrically opposite points at which the irradiance is a specified fraction of the beam's peak irradiance, and take the distance between them as a measure of the beam's width. An obvious choice for this fraction is ½ (−3 dB), in which case the diameter obtained is the full width of the beam at half its maximum intensity (FWHM). This is also called the half-power beam width (HPBW).", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [ 556970, 8410 ], "anchor_spans": [ [ 107, 117 ], [ 287, 289 ] ] }, { "plaintext": "The 1/e2 width is equal to the distance between the two points on the marginal distribution that are 1/e2 = 0.135 times the maximum value. In many cases, it makes more sense to take the distance between points where the intensity falls to 1/e2 = 0.135 times the maximum value. If there are more than two points that are 1/e2 times the maximum value, then the two points closest to the maximum are chosen. The 1/e2 width is important in the mathematics of Gaussian beams, in which the intensity profile is described by .", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [ 41206 ], "anchor_spans": [ [ 458, 471 ] ] }, { "plaintext": "The American National Standard Z136.1-2007 for Safe Use of Lasers (p.6) defines the beam diameter as the distance between diametrically opposed points in that cross-section of a beam where the power per unit area is 1/e (0.368) times that of the peak power per unit area. This is the beam diameter definition that is used for computing the maximum permissible exposure to a laser beam. In addition, the Federal Aviation Administration also uses the 1/e definition for laser safety calculations in FAA Order JO 7400.2, Para. 29-1-5d.", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Measurements of the 1/e2 width only depend on three points on the marginal distribution, unlike D4σ and knife-edge widths that depend on the integral of the marginal distribution. 1/e2 width measurements are noisier than D4σ width measurements. For multimodal marginal distributions (a beam profile with multiple peaks), the 1/e2 width usually does not yield a meaningful value and can grossly underestimate the inherent width of the beam. For multimodal distributions, the D4σ width is a better choice. For an ideal single-mode Gaussian beam, the D4σ, D86 and 1/e2 width measurements would give the same value.", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [ 516150 ], "anchor_spans": [ [ 251, 261 ] ] }, { "plaintext": "For a Gaussian beam, the relationship between the 1/e2 width and the full width at half maximum is , where is the full width of the beam at 1/e2.", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The D4σ width of a beam in the horizontal or vertical direction is 4 times σ, where σ is the standard deviation of the horizontal or vertical marginal distribution respectively. Mathematically, the D4σ beam width in the x dimension for the beam profile is expressed as", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [ 27590 ], "anchor_spans": [ [ 93, 111 ] ] }, { "plaintext": "where", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "is the centroid of the beam profile in the x direction.", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [ 187926 ], "anchor_spans": [ [ 7, 15 ] ] }, { "plaintext": "When a beam is measured with a laser beam profiler, the wings of the beam profile influence the D4σ value more than the center of the profile, since the wings are weighted by the square of its distance, x2, from the center of the beam. If the beam does not fill more than a third of the beam profiler's sensor area, then there will be a significant number of pixels at the edges of the sensor that register a small baseline value (the background value). If the baseline value is large or if it is not subtracted out of the image, then the computed D4σ value will be larger than the actual value because the baseline value near the edges of the sensor are weighted in the D4σ integral by x2. Therefore, baseline subtraction is necessary for accurate D4σ measurements. The baseline is easily measured by recording the average value for each pixel when the sensor is not illuminated. The D4σ width, unlike the FWHM and 1/e2 widths, is meaningful for multimodal marginal distributions — that is, beam profiles with multiple peaks — but requires careful subtraction of the baseline for accurate results. The D4σ is the ISO international standard definition for beam width.", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [ 15267398 ], "anchor_spans": [ [ 31, 50 ] ] }, { "plaintext": "Before the advent of the CCD beam profiler, the beam width was estimated using the knife-edge technique: slice a laser beam with a razor and measure the power of the clipped beam as a function of the razor position. The measured curve is the integral of the marginal distribution, and starts at the total beam power and decreases monotonically to zero power. The width of the beam is defined as the distance between the points of the measured curve that are 10% and 90% (or 20% and 80%) of the maximum value. If the baseline value is small or subtracted out, the knife-edge beam width always corresponds to 60%, in the case of 20/80, or 80%, in the case of 10/90, of the total beam power no matter what the beam profile. On the other hand, the D4σ, 1/e2, and FWHM widths encompass fractions of power that are beam-shape dependent. Therefore, the 10/90 or 20/80 knife-edge width is a useful metric when the user wishes to be sure that the width encompasses a fixed fraction of total beam power. Most CCD beam profiler's software can compute the knife-edge width numerically.", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [ 6804 ], "anchor_spans": [ [ 25, 28 ] ] }, { "plaintext": "The main drawback of the knife-edge technique is that the measured value is displayed only on the scanning direction, minimizing the amount of relevant beam information. To overcome this drawback, an innovative technology offered commercially allows multiple directions beam scanning to create an image like beam representation.", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "By mechanically moving the knife edge across the beam, the amount of energy impinging the detector area is determined by the obstruction. The profile is then measured from the knife-edge velocity and its relation to the detector's energy reading. Unlike other systems, a unique scanning technique uses several different oriented knife-edges to sweep across the beam. By using tomographic reconstruction, mathematical processes reconstruct the laser beam size in different orientations to an image similar to the one produced by CCD cameras. The main advantage of this scanning method is that it is free from pixel size limitations (as in CCD cameras) and allows beam reconstructions with wavelengths not usable with existing CCD technology. Reconstruction is possible for beams in deep UV to far IR.", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [ 995908 ], "anchor_spans": [ [ 377, 403 ] ] }, { "plaintext": "The D86 width is defined as the diameter of the circle that is centered at the centroid of the beam profile and contains 86% of the beam power. The solution for D86 is found by computing the area of increasingly larger circles around the centroid until the area contains 0.86 of the total power. Unlike the previous beam width definitions, the D86 width is not derived from marginal distributions. The percentage of 86, rather than 50, 80, or 90, is chosen because a circular Gaussian beam profile integrated down to 1/e2 of its peak value contains 86% of its total power. The D86 width is often used in applications that are concerned with knowing exactly how much power is in a given area. For example, applications of high-energy laser weapons and lidars require precise knowledge of how much transmitted power actually illuminates the target.", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [ 4714516, 41958 ], "anchor_spans": [ [ 737, 749 ], [ 755, 760 ] ] }, { "plaintext": "The definition given before holds for stigmatic (circular symmetric) beams only. For astigmatic beams, however, a more rigorous definition of the beam width has to be used:", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "and", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "This definition also incorporates information about x–y correlation , but for circular symmetric beams, both definitions are the same.", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Some new symbols appeared within the formulas, which are the first- and second-order moments:", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "the beam power ", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "and ", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Using this general definition, also the beam azimuthal angle can be expressed. It is the angle between the beam directions of minimal and maximal elongations, known as principal axes, and the laboratory system, being the and axes of the detector and given by ", "section_idx": 1, "section_name": "Definitions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "International standard ISO 11146-1:2005 specifies methods for measuring beam widths (diameters), divergence angles and beam propagation ratios of laser beams (if the beam is stigmatic) and for general astigmatic beams ISO 11146-2 is applicable. The D4σ beam width is the ISO standard definition and the measurement of the M² beam quality parameter requires the measurement of the D4σ widths.", "section_idx": 2, "section_name": "Measurement", "target_page_ids": [ 40781, 4443719 ], "anchor_spans": [ [ 97, 114 ], [ 322, 347 ] ] }, { "plaintext": "The other definitions provide complementary information to the D4σ. The D4σ and knife-edge widths are sensitive to the baseline value, whereas the 1/e2 and FWHM widths are not. The fraction of total beam power encompassed by the beam width depends on which definition is used.", "section_idx": 2, "section_name": "Measurement", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The width of laser beams can be measured by capturing an image on a camera, or by using a laser beam profiler.", "section_idx": 2, "section_name": "Measurement", "target_page_ids": [ 52648, 15267398 ], "anchor_spans": [ [ 68, 74 ], [ 90, 109 ] ] }, { "plaintext": "Beam waist", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 41206 ], "anchor_spans": [ [ 0, 10 ] ] }, { "plaintext": "Fresnel zone", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 41196 ], "anchor_spans": [ [ 0, 12 ] ] } ]

[ "Antennas_(radio)", "Optics" ]

[]

[ { "plaintext": "In electromagnetics, especially in optics, beam divergence is an angular measure of the increase in beam diameter or radius with distance from the optical aperture or antenna aperture from which the beam emerges. The term is relevant only in the \"far field\", away from any focus of the beam. Practically speaking, however, the far field can commence physically close to the radiating aperture, depending on aperture diameter and the operating wavelength.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 9532, 22483, 40780, 1780815, 47474, 1470583, 271708, 1032610 ], "anchor_spans": [ [ 3, 19 ], [ 35, 41 ], [ 100, 113 ], [ 117, 123 ], [ 147, 163 ], [ 167, 183 ], [ 247, 256 ], [ 273, 278 ] ] }, { "plaintext": "Beam divergence is often used to characterize electromagnetic beams in the optical regime, for cases in which the aperture from which the beam emerges is very large with respect to the wavelength. However, it is also used in the radio frequency (RF) band for cases in which the antenna is very large relative to a wavelength.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33125, 42852, 10134 ], "anchor_spans": [ [ 185, 195 ], [ 229, 244 ], [ 250, 254 ] ] }, { "plaintext": "Beam divergence usually refers to a beam of circular cross section, but not necessarily so. A beam may, for example, have an elliptical cross section, in which case the orientation of the beam divergence must be specified, for example with respect to the major or minor axis of the elliptical cross section.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The divergence of a beam can be calculated if one knows the beam diameter at two separate points far from any focus (Di, Df), and the distance (l) between these points. The beam divergence, , is given by ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "If a collimated beam is focused with a lens, the diameter of the beam in the rear focal plane of the lens is related to the divergence of the initial beam by ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 234654, 18320 ], "anchor_spans": [ [ 5, 20 ], [ 39, 43 ] ] }, { "plaintext": "where f is the focal length of the lens. Note that this measurement is valid only when the beam size is measured at the rear focal plane of the lens, i.e. where the focus would lie for a truly collimated beam, and not at the actual focus of the beam, which would occur behind the rear focal plane for a divergent beam.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Like all electromagnetic beams, lasers are subject to divergence, which is measured in milliradians (mrad) or degrees. For many applications, a lower-divergence beam is preferable. Neglecting divergence due to poor beam quality, the divergence of a laser beam is proportional to its wavelength and inversely proportional to the diameter of the beam at its narrowest point. For example, an ultraviolet laser that emits at a wavelength of 308nm will have a lower divergence than an infrared laser at 808nm, if both have the same minimum beam diameter. The divergence of good-quality laser beams is modeled using the mathematics of Gaussian beams.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 17556, 1730553, 1195294, 41206 ], "anchor_spans": [ [ 32, 37 ], [ 87, 98 ], [ 110, 116 ], [ 629, 642 ] ] }, { "plaintext": "Gaussian laser beams are said to be diffraction limited when their radial beam divergence is close to the minimum possible value, which is given by ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 376885 ], "anchor_spans": [ [ 36, 55 ] ] }, { "plaintext": "where is the laser wavelength and is the radius of the beam at its narrowest point, which is called the \"beam waist\". This type of beam divergence is observed from optimized laser cavities. Information on the diffraction-limited divergence of a coherent beam is inherently given by the N-slit interferometric equation.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 25474577 ], "anchor_spans": [ [ 290, 321 ] ] }, { "plaintext": "Laser beam profiler", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 15267398 ], "anchor_spans": [ [ 0, 19 ] ] }, { "plaintext": "Laser linewidth", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 30121934 ], "anchor_spans": [ [ 0, 15 ] ] }, { "plaintext": "Laser divergence calculator", "section_idx": 3, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Interactive beam divergence graph", "section_idx": 3, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] } ]

[ "Optics", "Antennas_(radio)" ]

[]

[ { "plaintext": "Beam steering is a technique for changing the direction of the main lobe of a radiation pattern.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 41345, 41620 ], "anchor_spans": [ [ 63, 72 ], [ 78, 95 ] ] }, { "plaintext": "In radio and radar systems, beam steering may be accomplished by switching the antenna elements or by changing the relative phases of the RF signals driving the elements. In recent days the beam steering is playing significant role in 5G communication because of quasi-optic nature of 5G frequencies.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 15368428, 25676, 1956288, 187317, 17604369, 42852, 23475353 ], "anchor_spans": [ [ 3, 8 ], [ 13, 18 ], [ 65, 74 ], [ 79, 86 ], [ 124, 130 ], [ 138, 147 ], [ 235, 237 ] ] }, { "plaintext": "In acoustics, beam steering is used to direct the audio from loudspeakers to a specific location in the listening area. This is done by changing the magnitude and phase of two or more loudspeakers installed in a column where the combined sound is added and cancelled at the required position. Commercially, this type of loudspeaker arrangement is known as a line array. This technique has been around for many years but since the emergence of modern Digital Signal Processing technology there are now many commercially available products on the market. Beam steering and directivity Control using DSP was pioneered in the early 1990s by Duran Audio who launched a technology called DDC (Digital Directivity Control).", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 1198, 45871, 15112, 9773128 ], "anchor_spans": [ [ 3, 12 ], [ 61, 72 ], [ 229, 243 ], [ 358, 368 ] ] }, { "plaintext": "In optical systems, beam steering may be accomplished by changing the refractive index of the medium through which the beam is transmitted or by the use of mirrors, prisms, lenses, or rotating diffraction gratings. Examples of optical beam steering approaches include mechanical mirror-based gimbals or beam-director units, galvanometer mechanisms that rotate mirrors, Risley prisms, phased-array optics, and microelectromechanical systems (MEMS) using micro-mirrors.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 22483, 25880, 41812, 20545, 282998, 18320, 41031, 342078, 40365, 282998, 9536761, 19638 ], "anchor_spans": [ [ 3, 17 ], [ 70, 86 ], [ 94, 100 ], [ 156, 162 ], [ 165, 170 ], [ 173, 177 ], [ 193, 212 ], [ 293, 299 ], [ 325, 337 ], [ 370, 383 ], [ 385, 404 ], [ 410, 439 ] ] }, { "plaintext": "Source: from Federal Standard 1037C", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 37310 ], "anchor_spans": [ [ 13, 35 ] ] }, { "plaintext": " Beamforming", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 1326932 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Electron optics", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 2220957 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": "Animation of beam steering using phased arrays on YouTube", "section_idx": 3, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Duran Audio's Digital Directivity Control Technology", "section_idx": 3, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Design of Cost-Effective Beam Steered Phased Array Antenna with Enhanced Gain using Metamaterial Lens", "section_idx": 3, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] } ]

[ "Antennas" ]

[ "beamsteering", "beam-steering" ]

[ { "plaintext": "__NOTOC__", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Bel can mean:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Belenus or Bel, a Celtic deity", "section_idx": 1, "section_name": "Mythology", "target_page_ids": [ 86089 ], "anchor_spans": [ [ 1, 8 ] ] }, { "plaintext": " Bel (mythology), a title (meaning \"lord\" or \"master\") for various gods in Babylonian religion", "section_idx": 1, "section_name": "Mythology", "target_page_ids": [ 93805 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Bel (name)", "section_idx": 2, "section_name": "People", "target_page_ids": [ 38541485 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " Annabel Linquist, known as Bel, American artist, musician, and entrepreneur", "section_idx": 2, "section_name": "People", "target_page_ids": [ 40493036 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Bél, the Hungarian name for Beliu Commune, Arad County, Romania", "section_idx": 3, "section_name": "Places", "target_page_ids": [ 5263258 ], "anchor_spans": [ [ 29, 34 ] ] }, { "plaintext": " Bel Mountain, in the Zagros Mountains of western and southwestern Iran", "section_idx": 3, "section_name": "Places", "target_page_ids": [ 499291 ], "anchor_spans": [ [ 22, 38 ] ] }, { "plaintext": " Bel, Iran (disambiguation)", "section_idx": 3, "section_name": "Places", "target_page_ids": [ 41915268 ], "anchor_spans": [ [ 1, 27 ] ] }, { "plaintext": " Bel, Osh, village in Osh Region, Kyrgyzstan", "section_idx": 3, "section_name": "Places", "target_page_ids": [ 16167516 ], "anchor_spans": [ [ 1, 9 ] ] }, { "plaintext": " Bel, Syria, village in Aleppo Governorate", "section_idx": 3, "section_name": "Places", "target_page_ids": [ 51540761 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " Temple of Bel in Palmyra, Syria", "section_idx": 3, "section_name": "Places", "target_page_ids": [ 9038287 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " Bel languages, spoken in northern Papua New Guinea", "section_idx": 4, "section_name": "Languages", "target_page_ids": [ 1995167 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " ISO 639 code for the Belarusian language", "section_idx": 4, "section_name": "Languages", "target_page_ids": [ 45213 ], "anchor_spans": [ [ 22, 41 ] ] }, { "plaintext": " Groupe Bel, a France-based multinational cheese distributor", "section_idx": 5, "section_name": "Other uses", "target_page_ids": [ 14116611 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " Bel (unit), an acoustic unit of measure equal to 10 decibels", "section_idx": 5, "section_name": "Other uses", "target_page_ids": [ 8410 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " BEL (disambiguation)", "section_idx": 6, "section_name": "See also", "target_page_ids": [ 1472027 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Bell (disambiguation)", "section_idx": 6, "section_name": "See also", "target_page_ids": [ 3711 ], "anchor_spans": [ [ 1, 22 ] ] }, { "plaintext": " Belle (disambiguation)", "section_idx": 6, "section_name": "See also", "target_page_ids": [ 527766 ], "anchor_spans": [ [ 1, 23 ] ] } ]

[]

[]

[ { "plaintext": "Bias is a disproportionate weight in favor of or against an idea or thing, usually in a way that is closed-minded, prejudicial, or unfair. Biases can be innate or learned. People may develop biases for or against an individual, a group, or a belief. In science and engineering, a bias is a systematic error. Statistical bias results from an unfair sampling of a population, or from an estimation process that does not give accurate results on average.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 36400847, 77182, 22346, 184099, 160361, 36687154 ], "anchor_spans": [ [ 100, 113 ], [ 115, 126 ], [ 290, 306 ], [ 308, 324 ], [ 348, 356 ], [ 385, 395 ] ] }, { "plaintext": "The word appears to derive from Old Provençal into Old French biais, \"sideways, askance, against the grain\". Whence comes French biais, \"a slant, a slope, an oblique\".", "section_idx": 1, "section_name": "Etymology", "target_page_ids": [ 99258, 22563904, 320082, 10597 ], "anchor_spans": [ [ 20, 26 ], [ 32, 45 ], [ 52, 62 ], [ 123, 129 ] ] }, { "plaintext": "It seems to have entered English via the game of bowls, where it referred to balls made with a greater weight on one side. Which expanded to the figurative use, \"a one-sided tendency of the mind\", and, at first especially in law, \"undue propensity or prejudice\".", "section_idx": 1, "section_name": "Etymology", "target_page_ids": [ 8569916, 4248 ], "anchor_spans": [ [ 25, 32 ], [ 49, 54 ] ] }, { "plaintext": "A cognitive bias is a repeating or basic misstep in thinking, assessing, recollecting, or other cognitive processes. That is, a pattern of deviation from standards in judgment, whereby inferences may be created unreasonably. People create their own \"subjective social reality\" from their own perceptions, their view of the world may dictate their behaviour. Thus, cognitive biases may sometimes lead to perceptual distortion, inaccurate judgment, illogical interpretation, or what is broadly called irrationality. However some cognitive biases are taken to be adaptive, and thus may lead to success in the appropriate situation. Furthermore, cognitive biases may allow speedier choices when speed is more valuable than precision. Other cognitive biases are a \"by-product\" of human processing limitations, coming about because of an absence of appropriate mental mechanisms, or just from human limitations in information processing.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 168622, 691626, 1686342, 70400, 315578 ], "anchor_spans": [ [ 261, 275 ], [ 499, 512 ], [ 560, 568 ], [ 832, 872 ], [ 908, 930 ] ] }, { "plaintext": "Anchoring is a psychological heuristic that describes the propensity to rely on the first piece of information encountered when making decisions. According to this heuristic, individuals begin with an implicitly suggested reference point (the \"anchor\") and make adjustments to it to reach their estimate. For example, the initial price offered for a used car sets the standard for the rest of the negotiations, so that prices lower than the initial price seem more reasonable even if they are still higher than what the car is worth.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 27988760, 18985062, 265752, 63452, 5146762, 22083, 211295 ], "anchor_spans": [ [ 15, 38 ], [ 99, 110 ], [ 128, 144 ], [ 164, 173 ], [ 350, 358 ], [ 397, 408 ], [ 419, 424 ] ] }, { "plaintext": "Apophenia, also known as patternicity, or agenticity, is the human tendency to perceive meaningful patterns within random data. Apophenia is well documented as a rationalization for gambling. Gamblers may imagine that they see patterns in the numbers which appear in lotteries, card games, or roulette wheels. One manifestation of this is known as the \"gambler's fallacy\".", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 19196523, 1706965, 228592, 5360, 26487, 12970 ], "anchor_spans": [ [ 115, 121 ], [ 162, 177 ], [ 267, 276 ], [ 278, 287 ], [ 293, 307 ], [ 353, 370 ] ] }, { "plaintext": "Pareidolia is the visual or auditory form of apophenia. It has been suggested that pareidolia combined with hierophany may have helped ancient societies organize chaos and make the world intelligible.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 8999824 ], "anchor_spans": [ [ 108, 118 ] ] }, { "plaintext": "An attribution bias can happen when individuals assess or attempt to discover explanations behind their own and others' behaviors. People make attributions about the causes of their own and others' behaviors; but these attributions don't necessarily precisely reflect reality. Rather than operating as objective perceivers, individuals are inclined to perceptual slips that prompt biased understandings of their social world. When judging others we tend to assume their actions are the result of internal factors such as personality, whereas we tend to assume our own actions arise because of the necessity of external circumstances. There are a wide range of sorts of attribution biases, such as the ultimate attribution error, fundamental attribution error, actor-observer bias, and self-serving bias.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 8087746, 177648, 511014, 19678111, 221319, 510995, 511068 ], "anchor_spans": [ [ 143, 155 ], [ 521, 532 ], [ 660, 665 ], [ 701, 727 ], [ 729, 758 ], [ 760, 779 ], [ 785, 802 ] ] }, { "plaintext": "Examples of attribution bias:", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Confirmation bias is the tendency to search for, interpret, favor, and recall information in a way that confirms one's beliefs or hypotheses while giving disproportionately less attention to information that contradicts it. The effect is stronger for emotionally charged issues and for deeply entrenched beliefs. People also tend to interpret ambiguous evidence as supporting their existing position. Biased search, interpretation and memory have been invoked to explain attitude polarization (when a disagreement becomes more extreme even though the different parties are exposed to the same evidence), belief perseverance (when beliefs persist after the evidence for them is shown to be false), the irrational primacy effect (a greater reliance on information encountered early in a series) and illusory correlation (when people falsely perceive an association between two events or situations). Confirmation biases contribute to overconfidence in personal beliefs and can maintain or strengthen beliefs in the face of contrary evidence. Poor decisions due to these biases have been found in political and organizational contexts.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 25524, 62433, 236809, 102883, 21073209, 10406, 511676, 59160, 1415118, 3080323, 265752 ], "anchor_spans": [ [ 37, 47 ], [ 49, 58 ], [ 71, 77 ], [ 119, 125 ], [ 130, 140 ], [ 251, 258 ], [ 471, 492 ], [ 604, 623 ], [ 797, 817 ], [ 932, 946 ], [ 1045, 1054 ] ] }, { "plaintext": "Framing involves the social construction of social phenomena by mass media sources, political or social movements, political leaders, and so on. It is an influence over how people organize, perceive, and communicate about reality. It can be positive or negative, depending on the audience and what kind of information is being presented. For political purposes, framing often presents facts in such a way that implicates a problem that is in need of a solution. Members of political parties attempt to frame issues in a way that makes a solution favoring their own political leaning appear as the most appropriate course of action for the situation at hand. As understood in social theory, framing is a schema of interpretation, a collection of anecdotes and stereotypes, that individuals rely on to understand and respond to events. People use filters to make sense of the world, the choices they then make are influenced by their creation of a frame.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 203510, 3452822, 19641, 75469, 55959, 43854, 317633, 1058555, 14511671, 481925, 18956166 ], "anchor_spans": [ [ 21, 40 ], [ 44, 60 ], [ 64, 74 ], [ 84, 113 ], [ 115, 132 ], [ 222, 229 ], [ 675, 688 ], [ 703, 709 ], [ 713, 727 ], [ 745, 754 ], [ 759, 769 ] ] }, { "plaintext": "Cultural bias is the related phenomenon of interpreting and judging phenomena by standards inherent to one's own culture. Numerous such biases exist, concerning cultural norms for color, location of body parts, mate selection, concepts of justice, linguistic and logical validity, acceptability of evidence, and taboos. Ordinary people may tend to imagine other people as basically the same, not significantly more or less valuable, probably attached emotionally to different groups and different land.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 7971785, 16369, 22760983, 46426065, 20550772, 61117 ], "anchor_spans": [ [ 211, 225 ], [ 239, 246 ], [ 248, 258 ], [ 263, 268 ], [ 298, 306 ], [ 312, 317 ] ] }, { "plaintext": "The halo effect and the horn effect are when an observer's overall impression of a person, organization, brand, or product influences their feelings about specifics of that entity's character or properties.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 22649, 105070, 18950900, 240410 ], "anchor_spans": [ [ 48, 58 ], [ 91, 103 ], [ 105, 110 ], [ 115, 122 ] ] }, { "plaintext": "The name halo effect is based on the concept of the saint's halo, and is a specific type of confirmation bias, wherein positive sentiments in one area cause questionable or unknown characteristics to be seen positively. If the observer likes one aspect of something, they will have a positive predisposition toward everything about it. A person's appearance has been found to produce a halo effect. The halo effect is also present in the field of brand marketing, affecting perception of companies and non-governmental organizations (NGOs).", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 2455406, 59160, 1053447, 18950900, 4918223, 46539 ], "anchor_spans": [ [ 52, 64 ], [ 92, 109 ], [ 349, 359 ], [ 449, 464 ], [ 490, 499 ], [ 504, 541 ] ] }, { "plaintext": "The opposite of the halo is the horn effect, when \"individuals believe (that negative) traits are inter-connected.\" The term horn effect refers to Devil's horns. It works in a negative direction: if the observer dislikes one aspect of something, they will have a negative predisposition towards other aspects.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 2261087 ], "anchor_spans": [ [ 147, 160 ] ] }, { "plaintext": "Both of these bias effects often clash with phrases such as \"words mean something\" and \"Your words have a history.\"", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Self-serving bias is the tendency for cognitive or perceptual processes to be distorted by the individual's need to maintain and enhance self-esteem. It is the propensity to credit accomplishment to our own capacities and endeavors, yet attribute failure to outside factors, to dismiss the legitimacy of negative criticism, concentrate on positive qualities and accomplishments yet disregard flaws and failures. Studies have demonstrated that this bias can affect behavior in the workplace, in interpersonal relationships, playing sports, and in consumer decisions.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 106238, 25140, 710166, 150497, 563299, 64589385, 161744, 25778403, 754957 ], "anchor_spans": [ [ 38, 47 ], [ 51, 61 ], [ 78, 87 ], [ 137, 148 ], [ 464, 472 ], [ 480, 489 ], [ 494, 521 ], [ 531, 536 ], [ 546, 564 ] ] }, { "plaintext": "Status quo bias is an emotional bias; a preference for the current state of affairs. The current baseline (or status quo) is taken as a reference point, and any change from that baseline is perceived as a loss.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 7175817 ], "anchor_spans": [ [ 22, 36 ] ] }, { "plaintext": "Status quo bias should be distinguished from a rational preference for the status quo ante, as when the current state of affairs is objectively superior to the available alternatives, or when imperfect information is a significant problem. A large body of evidence, however, shows that status quo bias frequently affects human decision-making.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 247315 ], "anchor_spans": [ [ 75, 85 ] ] }, { "plaintext": "A conflict of interest is when a person or association has intersecting interests (financial, personal, etc.) which could potentially corrupt. The potential conflict is autonomous of actual improper actions, it can be found and intentionally defused before corruption, or the appearance of corruption, happens. \"A conflict of interest is a set of circumstances that creates a risk that professional judgement or actions regarding a primary interest will be unduly influenced by a secondary interest.\" It exists if the circumstances are sensibly accepted to present a hazard that choices made may be unduly affected by auxiliary interests.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 219599, 105070, 11162, 20982422, 3608404, 48753248, 3608404 ], "anchor_spans": [ [ 33, 39 ], [ 43, 54 ], [ 83, 92 ], [ 94, 102 ], [ 134, 141 ], [ 190, 206 ], [ 257, 267 ] ] }, { "plaintext": "Bribery is giving of money, goods or other forms of recompense to in order to influence the recipient's behavior. Bribes can include money (including tips), goods, rights in action, property, privilege, emolument, gifts, perks, skimming, return favors, discounts, sweetheart deals, kickbacks, funding, donations, campaign contributions, sponsorships, stock options, secret commissions, or promotions. Expectations of when a monetary transaction is appropriate can differ from place to place. Political campaign contributions in the form of cash are considered criminal acts of bribery in some countries, while in the United States they are legal provided they adhere to election law. Tipping is considered bribery in some societies, but not others.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 8983183, 157901, 580039, 2975713, 23626, 829338, 1650660, 50021, 1633074, 255835, 630570, 256411, 1167063, 35545035, 805953, 367725, 339302, 545607, 9272073, 21636224, 1752418, 339302, 5785, 157901 ], "anchor_spans": [ [ 133, 138 ], [ 150, 154 ], [ 157, 162 ], [ 164, 180 ], [ 182, 190 ], [ 192, 201 ], [ 203, 212 ], [ 214, 218 ], [ 221, 226 ], [ 228, 236 ], [ 238, 251 ], [ 253, 262 ], [ 264, 279 ], [ 282, 291 ], [ 294, 301 ], [ 303, 311 ], [ 314, 335 ], [ 338, 349 ], [ 352, 365 ], [ 367, 384 ], [ 390, 400 ], [ 503, 525 ], [ 561, 574 ], [ 685, 692 ] ] }, { "plaintext": "Favoritism, sometimes known as in-group favoritism, or in-group bias, refers to a pattern of favoring members of one's in-group over out-group members. This can be expressed in evaluation of others, in allocation of resources, and in many other ways. This has been researched by psychologists, especially social psychologists, and linked to group conflict and prejudice. Cronyism is favoritism of long-standing friends, especially by appointing them to positions of authority, regardless of their qualifications. Nepotism is favoritism granted to relatives.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 2533750, 72132, 26990, 8313535, 77182, 356586, 313538, 265570 ], "anchor_spans": [ [ 119, 127 ], [ 279, 291 ], [ 305, 325 ], [ 341, 355 ], [ 360, 369 ], [ 371, 379 ], [ 513, 521 ], [ 547, 556 ] ] }, { "plaintext": "Lobbying is the attempt to influence choices made by administrators, frequently lawmakers or individuals from administrative agencies. Lobbyists may be among a legislator's constituencies, or not; they may engage in lobbying as a business, or not. Lobbying is often spoken of with contempt, the implication is that people with inordinate socioeconomic power are corrupting the law in order to serve their own interests. When people who have a duty to act on behalf of others, such as elected officials with a duty to serve their constituents' interests or more broadly the common good, stand to benefit by shaping the law to serve the interests of some private parties, there is a conflict of interest. This can lead to all sides in a debate looking to sway the issue by means of lobbyists.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 12229, 661622, 2782814, 667057, 39206, 918986, 147885, 3608404, 18949668, 183749, 312085 ], "anchor_spans": [ [ 53, 67 ], [ 80, 89 ], [ 110, 133 ], [ 173, 187 ], [ 230, 238 ], [ 281, 289 ], [ 338, 357 ], [ 362, 372 ], [ 377, 380 ], [ 444, 448 ], [ 574, 585 ] ] }, { "plaintext": "Self-regulation is the process whereby an organization monitors its own adherence to legal, ethical, or safety standards, rather than have an outside, independent agency such as a third party entity monitor and enforce those standards. Self-regulation of any group can create a conflict of interest. If any organization, such as a corporation or government bureaucracy, is asked to eliminate unethical behavior within their own group, it may be in their interest in the short run to eliminate the appearance of unethical behavior, rather than the behavior itself.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Regulatory capture is a form of political corruption that can occur when a regulatory agency, created to act in the public interest, instead advances the commercial or political concerns of special interest groups that dominate the industry or sector it is charged with regulating. Regulatory capture occurs because groups or individuals with a high-stakes interest in the outcome of policy or regulatory decisions can be expected to focus their resources and energies in attempting to gain the policy outcomes they prefer, while members of the public, each with only a tiny individual stake in the outcome, will ignore it altogether. Regulatory capture is a risk to which a regulatory agency is exposed by its very nature.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 66220, 2782814, 340401, 26561880 ], "anchor_spans": [ [ 32, 52 ], [ 75, 92 ], [ 116, 131 ], [ 198, 212 ] ] }, { "plaintext": "Shilling is deliberately giving spectators the feeling that one is an energetic autonomous client of a vendor for whom one is working. The effectiveness of shilling relies on crowd psychology to encourage other onlookers or audience members to purchase the goods or services (or accept the ideas being marketed). Shilling is illegal in some places, but legal in others. An example of shilling is paid reviews that give the impression of being autonomous opinions.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 234206, 155698, 157900, 538779 ], "anchor_spans": [ [ 91, 97 ], [ 103, 109 ], [ 175, 191 ], [ 396, 408 ] ] }, { "plaintext": "Statistical bias is a systematic tendency in the process of data collection, which results in lopsided, misleading results. This can occur in any of a number of ways, in the way the sample is selected, or in the way data are collected. It is a property of a statistical technique or of its results whereby the expected value of the results differs from the true underlying quantitative parameter being estimated.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 26685, 9653, 25065, 1565926 ], "anchor_spans": [ [ 258, 269 ], [ 310, 324 ], [ 386, 395 ], [ 402, 411 ] ] }, { "plaintext": "A forecast bias is when there are consistent differences between results and the forecasts of those quantities; that is: forecasts may have an overall tendency to be too high or too low.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The observer-expectancy effect is when a researcher's expectations cause them to subconsciously influence the people participating in an experiment. It is usually controlled using a double-blind system, and was an important reason for the development of double-blind experiments.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 25524, 1640288, 277248 ], "anchor_spans": [ [ 41, 53 ], [ 163, 173 ], [ 182, 201 ] ] }, { "plaintext": "In epidemiology and empirical research, reporting bias is defined as \"selective revealing or suppression of information\" of undesirable behavior by subjects or researchers.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 66997, 9545 ], "anchor_spans": [ [ 3, 15 ], [ 20, 38 ] ] }, { "plaintext": "It refers to a tendency to under-report unexpected or undesirable experimental results, while being more trusting of expected or desirable results. This can propagate, as each instance reinforces the status quo, and later experimenters justify their own reporting bias by observing that previous experimenters reported different results.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Social desirability bias is a bias within social science research where survey respondents can tend to answer questions in a manner that will be viewed positively by others. It can take the form of over-reporting laudable behavior, or under-reporting undesirable behavior. This bias interferes with the interpretation of average tendencies as well as individual differences. The inclination represents a major issue with self-report questionnaires; of special concern are self-reports of abilities, personalities, sexual behavior, and drug use.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 373212, 272134, 4144627, 177648, 14337, 25949 ], "anchor_spans": [ [ 42, 65 ], [ 72, 78 ], [ 421, 432 ], [ 499, 512 ], [ 514, 529 ], [ 535, 543 ] ] }, { "plaintext": "Selection bias is the conscious or unconscious bias introduced into a study by the way individuals, groups or data are selected for analysis, if such a way means that true randomization is not achieved, thereby ensuring that the sample obtained is not representative of the population intended to be analyzed. This results in a sample that may be significantly different from the overall population.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Bias and prejudice are usually considered to be closely related. Prejudice is prejudgment, or forming an opinion before becoming aware of the relevant facts of a case. The word is often used to refer to preconceived, usually unfavorable, judgments toward people or a person because of gender, political opinion, social class, age, disability, religion, sexuality, race/ethnicity, language, nationality, or other personal characteristics. Prejudice can also refer to unfounded beliefs and may include \"any unreasonable attitude that is unusually resistant to rational influence\".", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 38076, 29174, 16413778, 56285, 25414, 29252, 25614, 105004, 17524, 21583 ], "anchor_spans": [ [ 285, 291 ], [ 312, 324 ], [ 326, 329 ], [ 331, 341 ], [ 343, 351 ], [ 353, 362 ], [ 364, 368 ], [ 369, 378 ], [ 380, 388 ], [ 390, 401 ] ] }, { "plaintext": "Ageism is the stereotyping and/or discrimination against individuals or groups on the basis of their age. It can be used in reference to prejudicial attitudes towards older people, or towards younger people.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Classism is discrimination on the basis of social class. It includes attitudes that benefit the upper class at the expense of the lower class, or vice versa.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 8900, 29174, 454164, 1137466 ], "anchor_spans": [ [ 12, 26 ], [ 43, 55 ], [ 96, 107 ], [ 130, 141 ] ] }, { "plaintext": "Lookism is stereotypes, prejudice, and discrimination on the basis of physical attractiveness, or more generally to people whose appearance matches cultural preferences. Many people make automatic judgments of others based on their physical appearance that influence how they respond to those people.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 18956166, 77182, 8900, 1053447 ], "anchor_spans": [ [ 11, 21 ], [ 24, 33 ], [ 39, 53 ], [ 70, 93 ] ] }, { "plaintext": "Racism consists of ideologies based on a desire to dominate or a belief in the inferiority of another race. It may also hold that members of different races should be treated differently.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Sexism is discrimination based on a person's sex or gender. Sexism can affect any gender, but it is particularly documented as affecting women and girls. It has been linked to stereotypes and gender roles, and may include the belief that one sex or gender is intrinsically superior to another.", "section_idx": 2, "section_name": "Types of bias", "target_page_ids": [ 8900, 6116892, 18956166, 43094 ], "anchor_spans": [ [ 10, 24 ], [ 45, 58 ], [ 176, 186 ], [ 192, 203 ] ] }, { "plaintext": "Academic bias is the bias or perceived bias of scholars allowing their beliefs to shape their research and the scientific community. Claims of bias are often linked to claims by conservatives of pervasive bias against political conservatives and religious Christians. Some have argued that these claims are based upon anecdotal evidence which would not reliably indicate systematic bias, and have suggested that this divide is due to self-selection of conservatives choosing not to pursue academic careers.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [ 149170, 102883, 25524, 338705, 481925, 292154 ], "anchor_spans": [ [ 47, 55 ], [ 71, 77 ], [ 94, 102 ], [ 111, 131 ], [ 318, 336 ], [ 434, 448 ] ] }, { "plaintext": "There is some evidence that perception of classroom bias may be rooted in issues of sexuality, race, class and sex as much or more than in religion.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [ 5097395, 25613, 113664, 27165, 483260 ], "anchor_spans": [ [ 84, 93 ], [ 95, 99 ], [ 101, 106 ], [ 111, 114 ], [ 139, 147 ] ] }, { "plaintext": "In science research, experimenter bias occurs when experimenter expectancies regarding study results bias the research outcome. Examples of experimenter bias include conscious or unconscious influences on subject behavior including creation of demand characteristics that influence subjects, and altered or selective recording of experimental results themselves.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [ 59861, 59861, 26833, 33827415, 5658345, 511115 ], "anchor_spans": [ [ 3, 19 ], [ 87, 92 ], [ 110, 118 ], [ 179, 190 ], [ 244, 266 ], [ 307, 361 ] ] }, { "plaintext": "Funding bias refers to the tendency of a scientific study to support the interests of the study's financial sponsor. This phenomenon is recognized sufficiently that researchers undertake studies to examine bias in past published studies. It can be caused by any or all of: a conscious or subconscious sense of obligation of researchers towards their employers, misconduct or malpractice, publication bias, or reporting bias.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [ 1213355, 29537, 29537, 511115, 7806345 ], "anchor_spans": [ [ 301, 320 ], [ 361, 371 ], [ 375, 386 ], [ 388, 404 ], [ 409, 423 ] ] }, { "plaintext": "Full text on net (or FUTON) bias is a tendency of scholars to cite academic journals with open access—that is, journals that make their full text available on the internet without charge—in their own writing as compared with toll access publications. Scholars can more easily discover and access articles that have their full text on the internet, which increases authors' likelihood of reading, quoting, and citing these articles, this may increase the impact factor of open access journals relative to journals without open access.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [ 772062, 324572, 381219, 14539, 259338, 1036865 ], "anchor_spans": [ [ 50, 58 ], [ 67, 83 ], [ 90, 101 ], [ 163, 171 ], [ 225, 249 ], [ 455, 468 ] ] }, { "plaintext": "The related bias, no abstract available bias (NAA bias) is scholars' tendency to cite journal articles that have an abstract available online more readily than articles that do not.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [ 556400 ], "anchor_spans": [ [ 116, 124 ] ] }, { "plaintext": "Publication bias is a type of bias with regard to what academic research is likely to be published because of a tendency of researchers, and journal editors, to prefer some outcomes rather than others e.g. results showing a significant finding, leads to a problematic bias in the published literature. This can propagate further as literature reviews of claims about support for a hypothesis will themselves be biased if the original literature is contaminated by publication bias. Studies with significant results often do not appear to be superior to studies with a null result with respect to quality of design. However, statistically significant results have been shown to be three times more likely to be published compared to papers with null results.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [ 25524, 25524, 160995, 2644957, 21073209, 59861, 30875775, 9541 ], "anchor_spans": [ [ 64, 72 ], [ 124, 132 ], [ 224, 235 ], [ 332, 349 ], [ 381, 391 ], [ 482, 489 ], [ 568, 579 ], [ 607, 613 ] ] }, { "plaintext": "Driving while black refers to the racial profiling of African American drivers. The phrase implies that a motorist might be pulled over by a police officer, questioned, and searched, because of a racial bias.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [ 26131, 2154, 80750, 23627, 25613 ], "anchor_spans": [ [ 34, 50 ], [ 54, 70 ], [ 71, 78 ], [ 141, 147 ], [ 196, 207 ] ] }, { "plaintext": "Racial profiling, or ethnic profiling, is the act of suspecting or targeting a person of a certain race on the basis of racially observed characteristics or behavior, rather than on individual suspicion. Racial profiling is commonly referred to regarding its use by law enforcement, and its leading to discrimination against minorities.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [ 25614, 18486, 437868 ], "anchor_spans": [ [ 99, 103 ], [ 266, 281 ], [ 325, 335 ] ] }, { "plaintext": "Victim blaming occurs when the victim of a wrongful act is held at fault for the harm that befell them. The study of victimology seeks to mitigate the perception of victims as responsible.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [ 32573 ], "anchor_spans": [ [ 117, 128 ] ] }, { "plaintext": "Media bias is the bias or perceived bias of journalists and news producers within the mass media in the selection of events, the stories that are reported, and how they are covered. The term generally implies a pervasive or widespread bias violating the standards of journalism, rather than the perspective of an individual journalist or article. The level of media bias in different nations is debated. There are also watchdog groups that report on media bias.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [ 50100, 19826021, 19641, 1550016, 2526960 ], "anchor_spans": [ [ 44, 54 ], [ 60, 73 ], [ 86, 96 ], [ 251, 278 ], [ 420, 428 ] ] }, { "plaintext": "Practical limitations to media neutrality include the inability of journalists to report all available stories and facts, the requirement that selected facts be linked into a coherent narrative, government influence including overt and covert censorship, the influence of the owners of the news source, concentration of media ownership, the selection of staff, the preferences of an intended audience, and pressure from advertisers.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [ 12229, 17253537, 213897, 240400, 314993, 28737250, 696946, 2861 ], "anchor_spans": [ [ 195, 205 ], [ 243, 253 ], [ 276, 282 ], [ 303, 335 ], [ 354, 359 ], [ 365, 375 ], [ 392, 400 ], [ 420, 430 ] ] }, { "plaintext": "Bias has been a feature of the mass media since its birth with the invention of the printing press. The expense of early printing equipment restricted media production to a limited number of people. Historians have found that publishers often served the interests of powerful social groups.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [ 23295 ], "anchor_spans": [ [ 84, 98 ] ] }, { "plaintext": "Agenda setting describes the capacity of the media to focus on particular stories, if a news item is covered frequently and prominently, the audience will regard the issue as more important. That is, its salience will increase.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [ 2094955 ], "anchor_spans": [ [ 204, 212 ] ] }, { "plaintext": "Gatekeeping is the way in which information and news are filtered to the public, by each person or corporation along the way. It is the \"process of culling and crafting countless bits of information into the limited number of messages that reach people every day, and it is the center of the media's role in modern public life. [...] This process determines not only which information is selected, but also what the content and nature of the messages, such as news, will be.\"", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Sensationalism is when events and topics in news stories and pieces are overhyped to present skewed impressions of events, which may cause a misrepresentation of the truth of a story. Sensationalism may involve reporting about insignificant matters and events, or the presentation of newsworthy topics in a trivial or tabloid manner contrary to the standards of professional journalism.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [ 20781999, 3215667, 15928 ], "anchor_spans": [ [ 284, 294 ], [ 318, 325 ], [ 362, 385 ] ] }, { "plaintext": "Bias in education refers to real or perceived bias in the educational system. The content of school textbooks is often the issue of debate, as their target audience is young people, and the term \"whitewashing\" is used to refer to selective removal of critical or damaging evidence or comment. Religious bias in textbooks is observed in countries where religion plays a dominant role. There can be many forms of educational bias. Some overlooked aspects, occurring especially with the pedagogical circles of public and private schools—sources that are unrelated to fiduciary or mercantile impoverishment which may be unduly magnified—include teacher bias as well as a general bias against women who are going into STEM research.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Inductive bias occurs within the field of machine learning. In machine learning one seeks to develop algorithms that are able to learn to anticipate a particular output. To accomplish this, the learning algorithm is given training cases that show the expected connection. Then the learner is tested with new examples. Without further assumptions, this problem cannot be solved exactly as unknown situations may not be predictable. The inductive bias of the learning algorithm is the set of assumptions that the learner uses to predict outputs given inputs that it has not encountered. It may bias the learner towards the correct solution, the incorrect, or be correct some of the time. A classical example of an inductive bias is Occam's Razor, which assumes that the simplest consistent hypothesis is the best.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [ 233488, 775, 36797 ], "anchor_spans": [ [ 42, 58 ], [ 101, 110 ], [ 731, 744 ] ] }, { "plaintext": "Insider trading is the trading of a public company's stock or other securities (such as bonds or stock options) by individuals with access to non-public information about the company. In various countries, trading based on insider information is illegal because it is seen as unfair to other investors who do not have access to the information as the investor with insider information could potentially make far larger profits that a typical investor could make.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [ 262293, 19372783, 42162, 60737, 9272073, 2141578, 15368 ], "anchor_spans": [ [ 36, 50 ], [ 53, 58 ], [ 68, 78 ], [ 88, 93 ], [ 97, 110 ], [ 142, 164 ], [ 188, 205 ] ] }, { "plaintext": "In organized sports, match fixing occurs when a match is played to a completely or partially pre-determined result, violating the rules of the game and often the law. There is a variety of reasons for this, but the most common is in exchange for a payoff from gamblers. Players might also intentionally perform poorly to get an advantage in the future (such as a better draft pick, or an easier opponent in a playoff), or to rig a handicap system. Match-fixing generally refers to fixing the final result of the game. Another form of match-fixing, known as spot-fixing, involves fixing small events within a match which can be gambled upon, but which are unlikely to prove decisive in determining the final result of the game.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [ 25778403, 18723138, 472743, 616574, 74678, 1495803, 28627935 ], "anchor_spans": [ [ 13, 19 ], [ 48, 53 ], [ 270, 277 ], [ 370, 380 ], [ 409, 416 ], [ 431, 439 ], [ 557, 568 ] ] }, { "plaintext": "An implicit bias, or implicit stereotype, is the unconscious attribution of particular qualities to a member of a certain social group.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Implicit stereotypes are shaped by experience and based on learned associations between particular qualities and social categories, including race and/or gender. Individuals' perceptions and behaviors can be influenced by the implicit stereotypes they hold, even if they are unaware/unintentionally hold such stereotypes. Implicit bias is an aspect of implicit social cognition: the phenomenon that perceptions, attitudes, and stereotypes operate without conscious intention. The existence of implicit bias is supported by a variety of scientific articles in psychological literature. Implicit stereotype was first defined by psychologists Mahzarin Banaji and Anthony Greenwald in 1995.", "section_idx": 3, "section_name": "Contextual biases", "target_page_ids": [ 464804, 8287102, 17077378 ], "anchor_spans": [ [ 361, 377 ], [ 641, 656 ], [ 661, 678 ] ] }, { "plaintext": " Bias, unbiased, and both; essay on Blogspot", "section_idx": 6, "section_name": "External links", "target_page_ids": [ 304875 ], "anchor_spans": [ [ 36, 44 ] ] } ]

[ "Bias", "Communication_of_falsehoods", "Barriers_to_critical_thinking", "Prejudices" ]

[ "prejudice" ]

[ { "plaintext": "In telecommunication, the term bias distortion has the following meanings: ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374 ], "anchor_spans": [ [ 3, 20 ] ] }, { "plaintext": "Signal distortion resulting from a shift in the bias.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 275871, 41052, 40786 ], "anchor_spans": [ [ 0, 6 ], [ 7, 17 ], [ 48, 52 ] ] }, { "plaintext": "In digital signaling, distortion of the signal in which all the significant intervals have uniformly longer or shorter durations than their theoretical durations.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 8276, 41703 ], "anchor_spans": [ [ 3, 10 ], [ 11, 20 ] ] }, { "plaintext": "Bias distortion is expressed in percent of the system-specified unit interval.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 8286675, 49324 ], "anchor_spans": [ [ 47, 53 ], [ 64, 77 ] ] } ]

[ "Telecommunication_theory" ]

[]

[ { "plaintext": "In telecommunication, bilateral synchronization (or bilateral control) is a synchronization control system between exchanges A and B in which the clock at telephone exchange A controls the data received at exchange B and the clock at exchange B controls the data received at exchange A. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 28738, 275473, 182693, 26668156, 18985040 ], "anchor_spans": [ [ 3, 20 ], [ 76, 91 ], [ 92, 106 ], [ 146, 151 ], [ 155, 173 ], [ 189, 193 ] ] }, { "plaintext": "Bilateral synchronization is usually implemented by deriving the timing from the incoming bitstream.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 50082 ], "anchor_spans": [ [ 90, 99 ] ] }, { "plaintext": "Source: from Federal Standard 1037C in support of MIL-STD-188", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 37310, 41882 ], "anchor_spans": [ [ 13, 35 ], [ 50, 61 ] ] }, { "plaintext": " Plesiochronous digital hierarchy", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 38512 ], "anchor_spans": [ [ 1, 33 ] ] } ]

[ "Synchronization" ]

[]

[ { "plaintext": "In telecommunication, a bipolar signal is a signal that may assume either of two polarities, neither of which is zero. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 41703 ], "anchor_spans": [ [ 3, 20 ], [ 44, 50 ] ] }, { "plaintext": "A bipolar signal may have a two-state non-return-to-zero (NRZ) or a three-state return-to-zero (RZ) binary coding scheme. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 41425, 219202 ], "anchor_spans": [ [ 38, 56 ], [ 100, 113 ] ] }, { "plaintext": "A bipolar signal is usually symmetrical with respect to zero amplitude, i.e., the absolute values of the positive and negative signal states are nominally equal.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] } ]

[ "Telecommunication_theory" ]

[]

[ { "plaintext": "In telecommunication, the term bit-count integrity (BCI) has the following meanings: ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374 ], "anchor_spans": [ [ 3, 20 ] ] }, { "plaintext": "In message communications, the preservation of the exact number of bits that are in the original message.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 41367, 33094374 ], "anchor_spans": [ [ 3, 10 ], [ 11, 25 ] ] }, { "plaintext": "In connection-oriented services, preservation of the number of bits per unit time.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 346001, 30012 ], "anchor_spans": [ [ 3, 13 ], [ 77, 81 ] ] }, { "plaintext": "Note: Bit-count integrity is not the same as bit integrity, which requires that the delivered bits correspond exactly with the original bits.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 3364 ], "anchor_spans": [ [ 7, 10 ] ] }, { "plaintext": "Source: from Federal Standard 1037C and from MIL-STD-188", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 37310, 41882 ], "anchor_spans": [ [ 13, 35 ], [ 45, 56 ] ] } ]

[ "Data_transmission" ]

[]

[ { "plaintext": "In digital transmission, the number of bit errors is the number of received bits of a data stream over a communication channel that have been altered due to noise, interference, distortion or bit synchronization errors.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 42168, 3364, 47868, 156700, 3966982, 2889864, 41052, 41687 ], "anchor_spans": [ [ 3, 23 ], [ 76, 79 ], [ 86, 97 ], [ 105, 126 ], [ 157, 162 ], [ 164, 176 ], [ 178, 188 ], [ 192, 211 ] ] }, { "plaintext": "The bit error rate (BER) is the number of bit errors per unit time. The bit error ratio (also BER) is the number of bit errors divided by the total number of transferred bits during a studied time interval. Bit error ratio is a unitless performance measure, often expressed as a percentage.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 64493 ], "anchor_spans": [ [ 279, 289 ] ] }, { "plaintext": "The bit error probability pe is the expected value of the bit error ratio. The bit error ratio can be considered as an approximate estimate of the bit error probability. This estimate is accurate for a long time interval and a high number of bit errors.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 9653 ], "anchor_spans": [ [ 36, 50 ] ] }, { "plaintext": "As an example, assume this transmitted bit sequence:", "section_idx": 1, "section_name": "Example", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "1 1 0 0 0 1 0 1 1 ", "section_idx": 1, "section_name": "Example", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "and the following received bit sequence:", "section_idx": 1, "section_name": "Example", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "0 1 0 1 0 1 0 0 1,", "section_idx": 1, "section_name": "Example", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The number of bit errors (the underlined bits) is, in this case, 3. The BER is 3 incorrect bits divided by 9 transferred bits, resulting in a BER of 0.333 or 33.3%.", "section_idx": 1, "section_name": "Example", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The packet error ratio (PER) is the number of incorrectly received data packets divided by the total number of received packets. A packet is declared incorrect if at least one bit is erroneous. The expectation value of the PER is denoted packet error probability pp, which for a data packet length of N bits can be expressed as", "section_idx": 2, "section_name": "Packet error ratio", "target_page_ids": [ 43734 ], "anchor_spans": [ [ 67, 78 ] ] }, { "plaintext": ",", "section_idx": 2, "section_name": "Packet error ratio", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "assuming that the bit errors are independent of each other. For small bit error probabilities and large data packets, this is approximately", "section_idx": 2, "section_name": "Packet error ratio", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Similar measurements can be carried out for the transmission of frames, blocks, or symbols.", "section_idx": 2, "section_name": "Packet error ratio", "target_page_ids": [ 41172, 313667, 2518170 ], "anchor_spans": [ [ 64, 69 ], [ 72, 77 ], [ 83, 89 ] ] }, { "plaintext": "The above expression can be rearranged to express the corresponding BER (pe) as a function of the PER (pp) and the data packet length N in bits:", "section_idx": 2, "section_name": "Packet error ratio", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "In a communication system, the receiver side BER may be affected by transmission channel noise, interference, distortion, bit synchronization problems, attenuation, wireless multipath fading, etc.", "section_idx": 3, "section_name": "Factors affecting the BER", "target_page_ids": [ 3966982, 2889864, 41052, 41687, 40735, 41385, 81211 ], "anchor_spans": [ [ 89, 94 ], [ 96, 108 ], [ 110, 120 ], [ 122, 141 ], [ 152, 163 ], [ 174, 183 ], [ 184, 190 ] ] }, { "plaintext": "The BER may be improved by choosing a strong signal strength (unless this causes cross-talk and more bit errors), by choosing a slow and robust modulation scheme or line coding scheme, and by applying channel coding schemes such as redundant forward error correction codes.", "section_idx": 3, "section_name": "Factors affecting the BER", "target_page_ids": [ 20637, 41317, 4237207, 4237207 ], "anchor_spans": [ [ 144, 154 ], [ 165, 176 ], [ 201, 215 ], [ 242, 266 ] ] }, { "plaintext": "The transmission BER is the number of detected bits that are incorrect before error correction, divided by the total number of transferred bits (including redundant error codes). The information BER, approximately equal to the decoding error probability, is the number of decoded bits that remain incorrect after the error correction, divided by the total number of decoded bits (the useful information). Normally the transmission BER is larger than the information BER. The information BER is affected by the strength of the forward error correction code.", "section_idx": 3, "section_name": "Factors affecting the BER", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The BER may be evaluated using stochastic (Monte Carlo) computer simulations. If a simple transmission channel model and data source model is assumed, the BER may also be calculated analytically. An example of such a data source model is the Bernoulli source.", "section_idx": 4, "section_name": "Analysis of the BER", "target_page_ids": [ 56098, 156700, 1441002, 199189 ], "anchor_spans": [ [ 43, 54 ], [ 103, 116 ], [ 121, 132 ], [ 242, 251 ] ] }, { "plaintext": "Examples of simple channel models used in information theory are:", "section_idx": 4, "section_name": "Analysis of the BER", "target_page_ids": [ 14773 ], "anchor_spans": [ [ 42, 60 ] ] }, { "plaintext": " Binary symmetric channel (used in analysis of decoding error probability in case of non-bursty bit errors on the transmission channel)", "section_idx": 4, "section_name": "Analysis of the BER", "target_page_ids": [ 74361, 41119 ], "anchor_spans": [ [ 1, 25 ], [ 85, 106 ] ] }, { "plaintext": " Additive white Gaussian noise (AWGN) channel without fading.", "section_idx": 4, "section_name": "Analysis of the BER", "target_page_ids": [ 202097 ], "anchor_spans": [ [ 1, 30 ] ] }, { "plaintext": "A worst-case scenario is a completely random channel, where noise totally dominates over the useful signal. This results in a transmission BER of 50% (provided that a Bernoulli binary data source and a binary symmetrical channel are assumed, see below).", "section_idx": 4, "section_name": "Analysis of the BER", "target_page_ids": [ 199189 ], "anchor_spans": [ [ 167, 176 ] ] }, { "plaintext": "In a noisy channel, the BER is often expressed as a function of the normalized carrier-to-noise ratio measure denoted Eb/N0, (energy per bit to noise power spectral density ratio), or Es/N0 (energy per modulation symbol to noise spectral density).", "section_idx": 4, "section_name": "Analysis of the BER", "target_page_ids": [ 3994748, 1786306, 1786306 ], "anchor_spans": [ [ 79, 101 ], [ 118, 123 ], [ 184, 189 ] ] }, { "plaintext": "For example, in the case of QPSK modulation and AWGN channel, the BER as function of the Eb/N0 is given by:", "section_idx": 4, "section_name": "Analysis of the BER", "target_page_ids": [ 41551 ], "anchor_spans": [ [ 28, 32 ] ] }, { "plaintext": ".", "section_idx": 4, "section_name": "Analysis of the BER", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "People usually plot the BER curves to describe the performance of a digital communication system. In optical communication, BER(dB) vs. Received Power(dBm) is usually used; while in wireless communication, BER(dB) vs. SNR(dB) is used.", "section_idx": 4, "section_name": "Analysis of the BER", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Measuring the bit error ratio helps people choose the appropriate forward error correction codes. Since most such codes correct only bit-flips, but not bit-insertions or bit-deletions, the Hamming distance metric is the appropriate way to measure the number of bit errors. Many FEC coders also continuously measure the current BER.", "section_idx": 4, "section_name": "Analysis of the BER", "target_page_ids": [ 4237207, 41227 ], "anchor_spans": [ [ 66, 90 ], [ 189, 205 ] ] }, { "plaintext": "A more general way of measuring the number of bit errors is the Levenshtein distance.", "section_idx": 4, "section_name": "Analysis of the BER", "target_page_ids": [ 406418 ], "anchor_spans": [ [ 64, 84 ] ] }, { "plaintext": "The Levenshtein distance measurement is more appropriate for measuring raw channel performance before frame synchronization, and when using error correction codes designed to correct bit-insertions and bit-deletions, such as Marker Codes and Watermark Codes.", "section_idx": 4, "section_name": "Analysis of the BER", "target_page_ids": [ 41176 ], "anchor_spans": [ [ 102, 123 ] ] }, { "plaintext": "The BER is the likelihood of a bit misinterpretation due to electrical noise . Considering a bipolar NRZ transmission, we have", "section_idx": 5, "section_name": "Mathematical draft", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " for a \"1\" and for a \"0\". Each of and has a period of .", "section_idx": 5, "section_name": "Mathematical draft", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Knowing that the noise has a bilateral spectral density ,", "section_idx": 5, "section_name": "Mathematical draft", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " is ", "section_idx": 5, "section_name": "Mathematical draft", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "and is .", "section_idx": 5, "section_name": "Mathematical draft", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Returning to BER, we have the likelihood of a bit misinterpretation .", "section_idx": 5, "section_name": "Mathematical draft", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " and ", "section_idx": 5, "section_name": "Mathematical draft", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "where is the threshold of decision, set to 0 when .", "section_idx": 5, "section_name": "Mathematical draft", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "We can use the average energy of the signal to find the final expression :", "section_idx": 5, "section_name": "Mathematical draft", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "±§", "section_idx": 5, "section_name": "Mathematical draft", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "BERT or bit error rate test is a testing method for digital communication circuits that uses predetermined stress patterns consisting of a sequence of logical ones and zeros generated by a test pattern generator.", "section_idx": 6, "section_name": "Bit error rate test", "target_page_ids": [ 39068 ], "anchor_spans": [ [ 52, 82 ] ] }, { "plaintext": "A BERT typically consists of a test pattern generator and a receiver that can be set to the same pattern. They can be used in pairs, with one at either end of a transmission link, or singularly at one end with a loopback at the remote end. BERTs are typically stand-alone specialised instruments, but can be personal computer–based. In use, the number of errors, if any, are counted and presented as a ratio such as 1 in 1,000,000, or 1 in 1e06.", "section_idx": 6, "section_name": "Bit error rate test", "target_page_ids": [ 160478, 18457137 ], "anchor_spans": [ [ 213, 221 ], [ 310, 327 ] ] }, { "plaintext": "PRBS (pseudorandom binary sequence) – A pseudorandom binary sequencer of N Bits. These pattern sequences are used to measure jitter and eye mask of TX-Data in electrical and optical data links.", "section_idx": 6, "section_name": "Bit error rate test", "target_page_ids": [ 2006896, 41296 ], "anchor_spans": [ [ 6, 34 ], [ 125, 131 ] ] }, { "plaintext": "QRSS (quasi random signal source) – A pseudorandom binary sequencer which generates every combination of a 20-bit word, repeats every 1,048,575 words, and suppresses consecutive zeros to no more than 14. It contains high-density sequences, low-density sequences, and sequences that change from low to high and vice versa. This pattern is also the standard pattern used to measure jitter.", "section_idx": 6, "section_name": "Bit error rate test", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "3 in 24 – Pattern contains the longest string of consecutive zeros (15) with the lowest ones density (12.5%). This pattern simultaneously stresses minimum ones density and the maximum number of consecutive zeros. The D4 frame format of 3 in 24 may cause a D4 yellow alarm for frame circuits depending on the alignment of one bits to a frame.", "section_idx": 6, "section_name": "Bit error rate test", "target_page_ids": [ 962123 ], "anchor_spans": [ [ 218, 220 ] ] }, { "plaintext": "1:7 – Also referred to as 1 in 8. It has only a single one in an eight-bit repeating sequence. This pattern stresses the minimum ones density of 12.5% and should be used when testing facilities set for B8ZS coding as the 3 in 24 pattern increases to 29.5% when converted to B8ZS.", "section_idx": 6, "section_name": "Bit error rate test", "target_page_ids": [ 41378 ], "anchor_spans": [ [ 205, 209 ] ] }, { "plaintext": "Min/max – Pattern rapid sequence changes from low density to high density. Most useful when stressing the repeater's ALBO feature.", "section_idx": 6, "section_name": "Bit error rate test", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "All ones (or mark) – A pattern composed of ones only. This pattern causes the repeater to consume the maximum amount of power. If DC to the repeater is regulated properly, the repeater will have no trouble transmitting the long ones sequence. This pattern should be used when measuring span power regulation. An unframed all ones pattern is used to indicate an AIS (also known as a blue alarm).", "section_idx": 6, "section_name": "Bit error rate test", "target_page_ids": [ 2994865 ], "anchor_spans": [ [ 363, 366 ] ] }, { "plaintext": "All zeros – A pattern composed of zeros only. It is effective in finding equipment misoptioned for AMI, such as fiber/radio multiplex low-speed inputs.", "section_idx": 6, "section_name": "Bit error rate test", "target_page_ids": [ 1431410 ], "anchor_spans": [ [ 100, 103 ] ] }, { "plaintext": "Alternating 0s and 1s - A pattern composed of alternating ones and zeroes.", "section_idx": 6, "section_name": "Bit error rate test", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "2 in 8 – Pattern contains a maximum of four consecutive zeros. It will not invoke a B8ZS sequence because eight consecutive zeros are required to cause a B8ZS substitution. The pattern is effective in finding equipment misoptioned for B8ZS.", "section_idx": 6, "section_name": "Bit error rate test", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Bridgetap - Bridge taps within a span can be detected by employing a number of test patterns with a variety of ones and zeros densities. This test generates 21 test patterns and runs for 15 minutes. If a signal error occurs, the span may have one or more bridge taps. This pattern is only effective for T1 spans that transmit the signal raw. Modulation used in HDSL spans negates the bridgetap patterns' ability to uncover bridge taps.", "section_idx": 6, "section_name": "Bit error rate test", "target_page_ids": [ 2785436, 5649030 ], "anchor_spans": [ [ 12, 22 ], [ 361, 365 ] ] }, { "plaintext": "Multipat - This test generates five commonly used test patterns to allow DS1 span testing without having to select each test pattern individually. Patterns are: all ones, 1:7, 2 in 8, 3 in 24, and QRSS.", "section_idx": 6, "section_name": "Bit error rate test", "target_page_ids": [ 907542 ], "anchor_spans": [ [ 73, 76 ] ] }, { "plaintext": "T1-DALY and 55 OCTET - Each of these patterns contain fifty-five (55), eight bit octets of data in a sequence that changes rapidly between low and high density. These patterns are used primarily to stress the ALBO and equalizer circuitry but they will also stress timing recovery. 55 OCTET has fifteen (15) consecutive zeroes and can only be used unframed without violating one's density requirements. For framed signals, the T1-DALY pattern should be used. Both patterns will force a B8ZS code in circuits optioned for B8ZS.", "section_idx": 6, "section_name": "Bit error rate test", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "A bit error rate tester (BERT), also known as a \"bit error ratio tester\" or bit error rate test solution (BERTs) is electronic test equipment used to test the quality of signal transmission of single components or complete systems.", "section_idx": 7, "section_name": "Bit error rate tester", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The main building blocks of a BERT are:", "section_idx": 7, "section_name": "Bit error rate tester", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Pattern generator, which transmits a defined test pattern to the DUT or test system", "section_idx": 7, "section_name": "Bit error rate tester", "target_page_ids": [ 18567298, 5102157 ], "anchor_spans": [ [ 1, 18 ], [ 66, 69 ] ] }, { "plaintext": " Error detector connected to the DUT or test system, to count the errors generated by the DUT or test system", "section_idx": 7, "section_name": "Bit error rate tester", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Clock signal generator to synchronize the pattern generator and the error detector", "section_idx": 7, "section_name": "Bit error rate tester", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Digital communication analyser is optional to display the transmitted or received signal", "section_idx": 7, "section_name": "Bit error rate tester", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Electrical-optical converter and optical-electrical converter for testing optical communication signals", "section_idx": 7, "section_name": "Bit error rate tester", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Burst error", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 41119 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Error correction code", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 4237207 ], "anchor_spans": [ [ 1, 22 ] ] }, { "plaintext": " Errored second", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 30277300 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Pseudo bit error ratio", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 41496 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": " Viterbi Error Rate", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 27839509 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": "QPSK BER for AWGN channel – online experiment", "section_idx": 10, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "BER", "section_idx": 10, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] } ]

[ "Ratios", "Data_transmission", "Network_performance", "Error_measures" ]

[ "Bit error ratio", "BER" ]

[ { "plaintext": "In telecommunications, bit inversion means the changing of the state of a bit to the opposite state, i.e. the changing of a 0 bit to 1 or of a 1 bit to 0. It also refers to the changing of a state representing a given bit to the opposite state.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 3364 ], "anchor_spans": [ [ 3, 20 ], [ 74, 77 ] ] }, { "plaintext": "Source: Federal Standard 1037C and MIL-STD-188", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 37310, 41882 ], "anchor_spans": [ [ 8, 30 ], [ 35, 46 ] ] }, { "plaintext": " Bit error", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 40794 ], "anchor_spans": [ [ 1, 10 ] ] } ]

[ "Data_transmission" ]

[]

[ { "plaintext": "In telecommunication, bit pairing is the practice of establishing, within a code set, a number of subsets that have an identical bit representation except for the state of a specified bit. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 5295, 3364 ], "anchor_spans": [ [ 3, 20 ], [ 76, 84 ], [ 129, 132 ] ] }, { "plaintext": "Note: An example of bit pairing occurs in the International Alphabet No. 5 and the American Standard Code for Information Interchange (ASCII), where the upper case letters are related to their respective lower case letters by the state of bit six.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 670, 27065, 18985062, 586 ], "anchor_spans": [ [ 61, 69 ], [ 93, 101 ], [ 111, 122 ], [ 136, 141 ] ] } ]

[ "Data_transmission" ]

[]

[ { "plaintext": "In telecommunication, bit-sequence independence is a characteristic of some digital data transmission systems that impose no restrictions on, or modification of, the transmitted bit sequence.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 8276, 42168, 3364, 27838 ], "anchor_spans": [ [ 3, 20 ], [ 76, 83 ], [ 84, 101 ], [ 178, 181 ], [ 182, 190 ] ] }, { "plaintext": "Bit-sequence-independent protocols are in contrast to protocols that reserve certain bit sequences for special meanings, such as the flag sequence, 01111110, for HDLC, SDLC, and ADCCP protocols.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 41157, 78261, 476943, 40700 ], "anchor_spans": [ [ 133, 146 ], [ 162, 166 ], [ 168, 172 ], [ 178, 183 ] ] }, { "plaintext": "Bit-sequence-independence allows only line codes that have the same number of transitions per bit, otherwise, the line code is dependent on the bit sequence and, therefore, bit-sequence dependent.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] } ]

[ "Telecommunication_theory" ]

[]

[ { "plaintext": "In digital transmission, bit slip is the loss or gain of a bit or bits, caused by clock drift – variations in the respective clock rates of the transmitting and receiving devices.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 8276, 3364, 6083924, 182693 ], "anchor_spans": [ [ 3, 10 ], [ 59, 62 ], [ 82, 93 ], [ 125, 130 ] ] }, { "plaintext": "One cause of bit slippage is overflow of a receive buffer that occurs when the transmitter's clock rate exceeds that of the receiver. This causes one or more bits to be dropped for lack of storage capacity.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 4373, 2406183, 228385, 5300 ], "anchor_spans": [ [ 29, 37 ], [ 51, 57 ], [ 93, 103 ], [ 189, 196 ] ] }, { "plaintext": "One way to maintain timing between transmitting and receiving devices is to employ an asynchronous protocol such as start-stop. Alternatively, bit slip can be prevented by using a self-clocking signal (such as a signal modulated using OQPSK) or using a line coding such as Manchester encoding.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 2506, 200992, 291076, 41551, 41317, 41350 ], "anchor_spans": [ [ 86, 107 ], [ 116, 126 ], [ 181, 201 ], [ 236, 241 ], [ 254, 265 ], [ 274, 293 ] ] }, { "plaintext": "Another cause is \"losing count\", as on a hard drive: if a hard drive encounters a long string of 0s, without any 1s (or a string of 1s without 0s), it may lose track of the frame between fields, and suffer bit slip.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "When a pulse of N consecutive zero bits are sent, clock drift may cause the hardware to apparently detect N-1 zero bits or N+1 zero bits—both kinds of errors are called bit slip.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Thus one prevents long strings without change via such devices as run length limited codes.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 449077 ], "anchor_spans": [ [ 66, 84 ] ] }, { "plaintext": "Many communication systems use linear-feedback shift register scrambling to prevent long strings of 0s (or other symbol),", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 58992 ], "anchor_spans": [ [ 31, 72 ] ] }, { "plaintext": "including VSAT, 1000BASE-T, , etc.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 64636 ], "anchor_spans": [ [ 16, 26 ] ] }, { "plaintext": "While a scrambler makes the \"losing count\" type of bit slip error occur far less often,", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 41680 ], "anchor_spans": [ [ 8, 17 ] ] }, { "plaintext": "when bit slip errors do occur (perhaps for other reasons), ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "scramblers have the property of expanding small errors that add or lose a single bit into a much longer burst of errors.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The optimized cipher feedback mode (OCFB), the statistical self-synchronization mode, and the \"one-bit CFB mode\" also expand small bit-slip errors into a longer burst of errors, but eventually recover and produce the correct decrypted plaintext.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "A bit-slip error when using any other block cipher mode of operation generally results in complete corruption of the rest of the message.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 160202 ], "anchor_spans": [ [ 38, 68 ] ] }, { "plaintext": " Clock drift", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 6083924 ], "anchor_spans": [ [ 1, 12 ] ] } ]

[ "Data_synchronization" ]

[]

[ { "plaintext": "In telecommunication, the term bit-stream transmission has the following meanings:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374 ], "anchor_spans": [ [ 3, 20 ] ] }, { "plaintext": "1. In bit-oriented systems, the transmission of bit strings.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 3364, 609152 ], "anchor_spans": [ [ 7, 10 ], [ 33, 45 ] ] }, { "plaintext": "2. In character-oriented systems, the transmission of bit streams that represent characters.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 73443 ], "anchor_spans": [ [ 7, 16 ] ] }, { "plaintext": "In bit-stream transmission, the bits usually occur at fixed time intervals, start and stop signals are not used, and the bit patterns follow each other in sequence without interruption.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 30012, 27838 ], "anchor_spans": [ [ 60, 64 ], [ 155, 163 ] ] } ]

[]

[]

[ { "plaintext": "In data transmission and telecommunication, bit stuffing (also known—uncommonly—as positive justification) is the insertion of non-information bits into data. Stuffed bits should not be confused with overhead bits.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 42168, 33094374, 3364, 18985040, 12109789 ], "anchor_spans": [ [ 3, 20 ], [ 25, 42 ], [ 143, 147 ], [ 153, 157 ], [ 200, 212 ] ] }, { "plaintext": "Bit stuffing is used for various purposes, such as for bringing bit streams that do not necessarily have the same or rationally related bit rates up to a common rate, or to fill buffers or frames. The location of the stuffing bits is communicated to the receiving end of the data link, where these extra bits are removed to return the bit streams to their original bit rates or form. Bit stuffing may be used to synchronize several channels before multiplexing or to rate-match two single channels to each other.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 50082, 272290, 2406183, 41172, 40996, 41389 ], "anchor_spans": [ [ 64, 74 ], [ 136, 144 ], [ 178, 185 ], [ 189, 195 ], [ 275, 284 ], [ 448, 460 ] ] }, { "plaintext": "Another use of bit stuffing is for run length limited coding: to limit the number of consecutive bits of the same value in the data to be transmitted. A bit of the opposite value is inserted after the maximum allowed number of consecutive bits. Since this is a general rule the receiver doesn't need extra information about the location of the stuffing bits in order to do the de-stuffing. This is done to create additional signal transitions to ensure reliable reception or to escape special reserved code words such as frame sync sequences when the data happens to contain them.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 449077, 8207914 ], "anchor_spans": [ [ 35, 53 ], [ 527, 540 ] ] }, { "plaintext": "Bit stuffing does not ensure that the payload is intact (i.e. not corrupted by transmission errors); it is merely a way of attempting to ensure that the transmission starts and ends at the correct places. Error detection and correction techniques are used to check the frame for corruption after its delivery and, if necessary, the frame will be re-sent.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 10375 ], "anchor_spans": [ [ 205, 235 ] ] }, { "plaintext": "The NRZI coding scheme transmits a 0 bit as a signal transition, and a 1 bit as no change. In this case, bit stuffing is most easily described as the insertion of a 0 bit after a long run of 1 bits.", "section_idx": 1, "section_name": "Zero-bit insertion", "target_page_ids": [ 41425 ], "anchor_spans": [ [ 4, 8 ] ] }, { "plaintext": "It was popularized by IBM's SDLC (later renamed HDLC), and is also used in Low- and full-speed USB. ", "section_idx": 1, "section_name": "Zero-bit insertion", "target_page_ids": [ 476943, 78261, 32073 ], "anchor_spans": [ [ 28, 32 ], [ 48, 52 ], [ 95, 98 ] ] }, { "plaintext": "After a long sequence of 1 bits there would be no transitions in the transmitted data, and it would be possible for the transmitter and receiver clocks to lose synchronisation. By inserting a 0 after five (SDLC) or six (USB) consecutive 1 bits the transmitter guarantees a maximum of six (SDLC) or seven (USB) bit times between transitions. The receiver can synchronise its clock against the transitions to ensure proper data recovery.", "section_idx": 1, "section_name": "Zero-bit insertion", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "In SDLC the transmitted bit sequence \"01111110\" containing six adjacent 1 bits is the Flag byte. Bit stuffing ensures that this pattern can never occur in normal data, so it can be used as a marker for the beginning and end of the frame without any possibility of being confused with normal data.", "section_idx": 1, "section_name": "Zero-bit insertion", "target_page_ids": [ 78261 ], "anchor_spans": [ [ 86, 95 ] ] }, { "plaintext": "The main disadvantage of bit-stuffing is that the code rate is unpredictable; it depends on the data being transmitted.", "section_idx": 1, "section_name": "Zero-bit insertion", "target_page_ids": [ 7981806 ], "anchor_spans": [ [ 50, 59 ] ] }, { "plaintext": "Source: from Federal Standard 1037C in support of MIL-STD-188", "section_idx": 1, "section_name": "Zero-bit insertion", "target_page_ids": [ 37310, 41882 ], "anchor_spans": [ [ 13, 35 ], [ 50, 61 ] ] }, { "plaintext": " Consistent Overhead Byte Stuffing", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 29719643 ], "anchor_spans": [ [ 1, 34 ] ] } ]

[ "Line_codes", "Synchronization" ]

[]

[ { "plaintext": "Bit-synchronous operation is a type of digital communication in which the data circuit-terminating equipment (DCE), data terminal equipment (DTE), and transmitting circuits are all operated in bit synchronism with a clock signal.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 18985040, 346001, 41005, 41786, 74041, 3364, 1627129, 182693 ], "anchor_spans": [ [ 74, 78 ], [ 79, 86 ], [ 110, 113 ], [ 121, 139 ], [ 141, 144 ], [ 193, 196 ], [ 197, 208 ], [ 216, 228 ] ] }, { "plaintext": "In bit-synchronous operation, clock timing is usually delivered at twice the modulation rate, and one bit is transmitted or received during each clock cycle.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 1627129, 2518170 ], "anchor_spans": [ [ 7, 18 ], [ 77, 92 ] ] }, { "plaintext": "Bit-synchronous operation is sometimes erroneously referred to as digital synchronization.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] } ]

[ "Line_codes" ]

[]

[ { "plaintext": "A blind transmission, in telecommunications, is a transmission made without obtaining a receipt, or acknowledgment of reception, from the intended receiving station. Blind transmissions may occur or be necessary when security constraints, such as radio silence, are imposed, when technical difficulties with a sender's receiver or receiver's transmitter occur, or when lack of time precludes the delay caused by waiting for receipts.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 3006317, 61164 ], "anchor_spans": [ [ 25, 43 ], [ 319, 327 ], [ 342, 353 ] ] }, { "plaintext": "In aviation it is common to \"transmit in the blind\" when an aircraft is approaching a non-towered airport. The pilot will broadcast his position and intentions over a common frequency. If no other aircraft are in the traffic pattern, the pilot continues to transmit his position in the blind in case another aircraft is in the area but unable to respond.", "section_idx": 1, "section_name": "Examples", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The less common reason would be a ground control station not being able to transmit (due to transmitter failure) or not wanting to transmit any acknowledgment (to avoid giving away further information and putting a military mission at risk).", "section_idx": 1, "section_name": "Examples", "target_page_ids": [ 633350 ], "anchor_spans": [ [ 34, 56 ] ] }, { "plaintext": "Transmission time", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 6426596 ], "anchor_spans": [ [ 0, 17 ] ] } ]

[ "Telecommunications_techniques" ]

[]

[ { "plaintext": "Block or blocked may refer to:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Block programming, the result of a programming strategy in broadcasting", "section_idx": 1, "section_name": "Arts, entertainment and media", "target_page_ids": [ 2836685 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " W242BX, a radio station licensed to Greenville, South Carolina, United States known as 96.3 the Block ", "section_idx": 1, "section_name": "Arts, entertainment and media", "target_page_ids": [ 6083806 ], "anchor_spans": [ [ 1, 7 ] ] }, { "plaintext": " WFNZ-FM, a radio station licensed to Harrisburg, North Carolina, United States, branded as 92.7 The Block", "section_idx": 1, "section_name": "Arts, entertainment and media", "target_page_ids": [ 6776699 ], "anchor_spans": [ [ 1, 8 ] ] }, { "plaintext": " Blocked (The Flash), an episode of the television series The Flash", "section_idx": 1, "section_name": "Arts, entertainment and media", "target_page_ids": [ 57013642 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " Block Entertainment, a record label", "section_idx": 1, "section_name": "Arts, entertainment and media", "target_page_ids": [ 7846162 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " Blocks Recording Club, a record label", "section_idx": 1, "section_name": "Arts, entertainment and media", "target_page_ids": [ 7064202 ], "anchor_spans": [ [ 1, 22 ] ] }, { "plaintext": " Woodblock (instrument), a small piece of slit drum made from one piece of wood and used as a percussion instrument", "section_idx": 1, "section_name": "Arts, entertainment and media", "target_page_ids": [ 306682 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": " \"Blocks\", by C418 from Minecraft - Volume Beta, 2013", "section_idx": 1, "section_name": "Arts, entertainment and media", "target_page_ids": [ 36711106 ], "anchor_spans": [ [ 24, 47 ] ] }, { "plaintext": " Toy block, one of a set of wooden or plastic pieces, of various shapes", "section_idx": 1, "section_name": "Arts, entertainment and media", "target_page_ids": [ 4345964 ], "anchor_spans": [ [ 1, 10 ] ] }, { "plaintext": " Unit block, a type of standardized wooden toy block for children", "section_idx": 1, "section_name": "Arts, entertainment and media", "target_page_ids": [ 15007701 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " Blocked (video game), a puzzle game for the iPhone and iPod Touch", "section_idx": 1, "section_name": "Arts, entertainment and media", "target_page_ids": [ 25375191 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Breeze block, cinder block or cement block, a concrete masonry unit for building", "section_idx": 2, "section_name": "Building and construction", "target_page_ids": [ 1103580 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Compressed earth block, a building block or unit for construction", "section_idx": 2, "section_name": "Building and construction", "target_page_ids": [ 7876225 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": " Tower block, a high-rise building", "section_idx": 2, "section_name": "Building and construction", "target_page_ids": [ 118767 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Block (district subdivision), administrative region in some South Asian countries", "section_idx": 3, "section_name": "Land subdivisions", "target_page_ids": [ 5482879 ], "anchor_spans": [ [ 1, 29 ] ] }, { "plaintext": " Block (rural Australia), a small agricultural landholding", "section_idx": 3, "section_name": "Land subdivisions", "target_page_ids": [ 49123418 ], "anchor_spans": [ [ 1, 24 ] ] }, { "plaintext": " City block, the smallest area that is surrounded by streets", "section_idx": 3, "section_name": "Land subdivisions", "target_page_ids": [ 948686 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " Block, Illinois, an unincorporated community, US", "section_idx": 4, "section_name": "Places", "target_page_ids": [ 24242956 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Block, Kansas, an unincorporated community, US", "section_idx": 4, "section_name": "Places", "target_page_ids": [ 57116681 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " Block, Tennessee, an unincorporated community, US", "section_idx": 4, "section_name": "Places", "target_page_ids": [ 37274151 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Block Island, an island in the state of Rhode Island, US", "section_idx": 4, "section_name": "Places", "target_page_ids": [ 437471 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Block (periodic table), a set of adjacent groups in the periodic table", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 33563967 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": " Block (meteorology), large-scale patterns in the atmospheric pressure field", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 3902153 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " Fault block, a geologic zone or geologic province", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 5470669 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Block, Inc., an American technology company formerly known as Square ", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 27355700 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Block (blockchain), a segment of an open list of data records", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 44065971 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": " Block (data storage), the practice of storing electronic data in equally sized units", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 313667 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Block (Internet), technical measures to restrict users' access to certain internet resources", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 13842515 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Blocking access to certain websites is one form of internet censorship ", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 11056386 ], "anchor_spans": [ [ 52, 71 ] ] }, { "plaintext": " Block (programming), a group of declarations and statements treated as a unit", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 381944 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " Block (telecommunications), a unit of data transmission", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 3608159 ], "anchor_spans": [ [ 1, 27 ] ] }, { "plaintext": " Block artifact, a type of distortion in a compressed image", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 185669 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Block-level element, in the HTML markup language", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 274393 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " Blocks (C language extension), an extension to the C programming language designed to support parallel programming", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 24318293 ], "anchor_spans": [ [ 1, 30 ] ] }, { "plaintext": " Unicode block, a named range of codepoints in Unicode", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 1039191 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " Block Elements, a Unicode block of block-shaped characters", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 5964051 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Engine block and cylinder block, the main part of an internal combustion engine", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 1414527 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Block (sailing), a single or multiple pulley used on sailboats", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 1162721 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Nerve block, or regional nerve blockade, any deliberate interruption of signals traveling along a nerve, often for the purpose of pain relief", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 2684099 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Local anesthetic nerve block (sometimes referred to as simply \"nerve block\"), a short-term block", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 41564423 ], "anchor_spans": [ [ 1, 29 ] ] }, { "plaintext": " Nerve block, the deliberate temporary degeneration of nerve fibers to produce a block that may persist for weeks, months, or indefinitely", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 2684099 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Neurectomy, the cutting through or removal of a nerve or a section of a nerve, which usually produces a permanent block", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 5746486 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " Third-degree atrioventricular block (AV block), a medical condition", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 637763 ], "anchor_spans": [ [ 1, 36 ] ] }, { "plaintext": " Block (permutation group theory)", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 3769397 ], "anchor_spans": [ [ 1, 33 ] ] }, { "plaintext": " Block, in modular representation theory", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 1110685 ], "anchor_spans": [ [ 11, 40 ] ] }, { "plaintext": " Block, in graph theory, is a biconnected component, a maximal biconnected subgraph of a graph", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 4842394 ], "anchor_spans": [ [ 31, 52 ] ] }, { "plaintext": " Aschbacher block of a finite group", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 29649460 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Block design, a kind of set system in combinatorial mathematics", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 1188184 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Block matrix", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 457464 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Block of a ring, a centrally primitive idempotent or the ideal it generates", "section_idx": 5, "section_name": "Science and technology", "target_page_ids": [ 30189901 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Block, a defensive shot in pickleball", "section_idx": 6, "section_name": "Sports", "target_page_ids": [ 70449119 ], "anchor_spans": [ [ 28, 38 ] ] }, { "plaintext": " Block (basketball), when a defensive player legally deflects a shot", "section_idx": 6, "section_name": "Sports", "target_page_ids": [ 1829132 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": " Blocking (martial arts)", "section_idx": 6, "section_name": "Sports", "target_page_ids": [ 509595 ], "anchor_spans": [ [ 1, 24 ] ] }, { "plaintext": " Starting blocks, devices used by sprinters to assist in preventing their feet from slipping as they break into a run", "section_idx": 6, "section_name": "Sports", "target_page_ids": [ 27487639 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Block (cricket), when a batsman deflects the ball to avoid getting out", "section_idx": 6, "section_name": "Sports", "target_page_ids": [ 673526 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " The Block (basketball), a defensive play in game 7 of the 2016 NBA Finals", "section_idx": 6, "section_name": "Sports", "target_page_ids": [ 50888840 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": " Block number, a system to differentiate between groups of aircraft of the same type with minor variants", "section_idx": 7, "section_name": "Transportation", "target_page_ids": [ 1075587 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Signalling block system, a way of controlling train movement", "section_idx": 7, "section_name": "Transportation", "target_page_ids": [ 5875823 ], "anchor_spans": [ [ 1, 24 ] ] }, { "plaintext": " Block (musician) (Jamie Block), an anti-folk musician based in New York, US", "section_idx": 8, "section_name": "People", "target_page_ids": [ 35747516 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Block letters (also known as printscript, manuscript, print writing, or ball and stick in academics), a sans-serif (or \"Gothic\") style of writing", "section_idx": 9, "section_name": "Other uses", "target_page_ids": [ 1155571 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " Block party (also known as street party), a community social event", "section_idx": 9, "section_name": "Other uses", "target_page_ids": [ 624436 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Block scheduling, a type of academic scheduling", "section_idx": 9, "section_name": "Other uses", "target_page_ids": [ 2917415 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Hat block, or block shaper, a wooden block carved into the shape of a hat by a craftsman", "section_idx": 9, "section_name": "Other uses", "target_page_ids": [ 15625711 ], "anchor_spans": [ [ 1, 10 ] ] }, { "plaintext": " Postage stamp block, an attached group of postage stamps", "section_idx": 9, "section_name": "Other uses", "target_page_ids": [ 357236 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " The Block (disambiguation)", "section_idx": 10, "section_name": "See also", "target_page_ids": [ 1695575 ], "anchor_spans": [ [ 1, 27 ] ] }, { "plaintext": " Bloc (disambiguation)", "section_idx": 10, "section_name": "See also", "target_page_ids": [ 605267 ], "anchor_spans": [ [ 1, 22 ] ] }, { "plaintext": " Blockade (disambiguation)", "section_idx": 10, "section_name": "See also", "target_page_ids": [ 14324291 ], "anchor_spans": [ [ 1, 26 ] ] }, { "plaintext": " Blockbuster (disambiguation)", "section_idx": 10, "section_name": "See also", "target_page_ids": [ 1724918 ], "anchor_spans": [ [ 1, 29 ] ] }, { "plaintext": " Blocker (disambiguation)", "section_idx": 10, "section_name": "See also", "target_page_ids": [ 1054625 ], "anchor_spans": [ [ 1, 25 ] ] }, { "plaintext": " Blocking (disambiguation)", "section_idx": 10, "section_name": "See also", "target_page_ids": [ 40810 ], "anchor_spans": [ [ 1, 26 ] ] } ]

[]

[]

[ { "plaintext": "In telecommunications, a block check character (BCC) is a character added to a transmission block to facilitate error detection.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 73443, 41808, 10375 ], "anchor_spans": [ [ 3, 20 ], [ 58, 67 ], [ 79, 97 ], [ 112, 127 ] ] }, { "plaintext": "In longitudinal redundancy checking and cyclic redundancy checking, block check characters are computed for, and added to, each message block transmitted. This block check character is compared with a second block check character computed by the receiver to determine whether the transmission is error free.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 41334, 38838, 41367 ], "anchor_spans": [ [ 3, 32 ], [ 40, 63 ], [ 128, 135 ] ] } ]

[ "Control_characters" ]

[]

[ { "plaintext": "Blocking may refer to:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Blacklist (computing)", "section_idx": 1, "section_name": "Science, technology, and mathematics", "target_page_ids": [ 16988945 ], "anchor_spans": [ [ 0, 21 ] ] }, { "plaintext": "Blocking (computing), holding up a task until an event occurs", "section_idx": 1, "section_name": "Science, technology, and mathematics", "target_page_ids": [ 14806503 ], "anchor_spans": [ [ 0, 20 ] ] }, { "plaintext": "Blocking (radio), interference by an off-frequency signal", "section_idx": 1, "section_name": "Science, technology, and mathematics", "target_page_ids": [ 24837293 ], "anchor_spans": [ [ 0, 16 ] ] }, { "plaintext": "Blocking probability, for calls in a telecommunications system", "section_idx": 1, "section_name": "Science, technology, and mathematics", "target_page_ids": [ 10283 ], "anchor_spans": [ [ 0, 20 ] ] }, { "plaintext": "Head-of-line blocking, in some network switching fabrics", "section_idx": 1, "section_name": "Science, technology, and mathematics", "target_page_ids": [ 5031225 ], "anchor_spans": [ [ 0, 21 ] ] }, { "plaintext": "Internet blocking; see Block (Internet)", "section_idx": 1, "section_name": "Science, technology, and mathematics", "target_page_ids": [ 13842515 ], "anchor_spans": [ [ 23, 39 ] ] }, { "plaintext": "Thought blocking, a type of thought disorder", "section_idx": 1, "section_name": "Science, technology, and mathematics", "target_page_ids": [ 28090107 ], "anchor_spans": [ [ 0, 16 ] ] }, { "plaintext": "Blocking effect, in psychology", "section_idx": 1, "section_name": "Science, technology, and mathematics", "target_page_ids": [ 10302211 ], "anchor_spans": [ [ 0, 15 ] ] }, { "plaintext": "Mental block, a type of suppression or repression", "section_idx": 1, "section_name": "Science, technology, and mathematics", "target_page_ids": [ 1853648 ], "anchor_spans": [ [ 0, 12 ] ] }, { "plaintext": "Blocking (linguistics), where the existence of a competing form blocks the application of a morphological process", "section_idx": 1, "section_name": "Science, technology, and mathematics", "target_page_ids": [ 32068953 ], "anchor_spans": [ [ 0, 22 ] ] }, { "plaintext": "Blocking (statistics), in the design of experiments, the arranging of experimental units in groups (blocks) which are similar to one another", "section_idx": 1, "section_name": "Science, technology, and mathematics", "target_page_ids": [ 1822339 ], "anchor_spans": [ [ 0, 21 ] ] }, { "plaintext": "Atmospheric blocking, a phenomenon in meteorology of large scale stationary pressure cells", "section_idx": 1, "section_name": "Science, technology, and mathematics", "target_page_ids": [ 3902153 ], "anchor_spans": [ [ 0, 20 ] ] }, { "plaintext": "Blocking, in the western blot technique, a process to prevent unwanted binding of antibodies to a membrane", "section_idx": 1, "section_name": "Science, technology, and mathematics", "target_page_ids": [ 174030 ], "anchor_spans": [ [ 17, 29 ] ] }, { "plaintext": "Blocking (construction), short boards used as reinforcement or to provide attachment points in wood-framed and other forms of construction", "section_idx": 1, "section_name": "Science, technology, and mathematics", "target_page_ids": [ 6950605 ], "anchor_spans": [ [ 0, 23 ] ] }, { "plaintext": "Blocking (American football), the legal interference with another player's motion", "section_idx": 2, "section_name": "Sport", "target_page_ids": [ 2719597 ], "anchor_spans": [ [ 0, 28 ] ] }, { "plaintext": "Blocking (martial arts), a defensive technique in martial arts", "section_idx": 2, "section_name": "Sport", "target_page_ids": [ 509595 ], "anchor_spans": [ [ 0, 23 ] ] }, { "plaintext": "Blocking (stage), the movement and positioning of actors on a stage, or within a frame in film", "section_idx": 3, "section_name": "Theatre and film", "target_page_ids": [ 1377755 ], "anchor_spans": [ [ 0, 16 ] ] }, { "plaintext": "Blocking (animation), a technique in which key poses establish timing and placement of items in a scene", "section_idx": 3, "section_name": "Theatre and film", "target_page_ids": [ 7368847 ], "anchor_spans": [ [ 0, 20 ] ] }, { "plaintext": "Blocking (textile arts), the process of stretching a knitted garment into shape while wet or using steam", "section_idx": 4, "section_name": "Other uses", "target_page_ids": [ 5545599 ], "anchor_spans": [ [ 0, 23 ] ] }, { "plaintext": "Blocking (transport), the process of dividing a transit schedule into parts that can be operated by a single vehicle", "section_idx": 4, "section_name": "Other uses", "target_page_ids": [ 46899479 ], "anchor_spans": [ [ 0, 20 ] ] }, { "plaintext": "Blocking troops - military barrier troops positioned to forestall unauthorised retreats", "section_idx": 4, "section_name": "Other uses", "target_page_ids": [ 3115308 ], "anchor_spans": [ [ 27, 41 ] ] }, { "plaintext": "Block (disambiguation)", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 40808 ], "anchor_spans": [ [ 0, 22 ] ] }, { "plaintext": "Non-blocking (disambiguation)", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 5961198 ], "anchor_spans": [ [ 0, 29 ] ] } ]

[]

[]

[ { "plaintext": "Bonding may refer to:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Bonding (TV series), a 2019 Netflix Original TV series", "section_idx": 1, "section_name": "Arts and entertainment", "target_page_ids": [ 60567238 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " \"Bonding\" (Kim Possible), a 2004 episode of the television series Kim Possible", "section_idx": 1, "section_name": "Arts and entertainment", "target_page_ids": [ 2623498 ], "anchor_spans": [ [ 1, 25 ] ] }, { "plaintext": " \"The Bonding\", a 1989 episode of the television series Star Trek: The Next Generation", "section_idx": 1, "section_name": "Arts and entertainment", "target_page_ids": [ 3125912 ], "anchor_spans": [ [ 2, 13 ] ] }, { "plaintext": " The Bonding (album), a 2013 album by Austrian symphonic metal band Edenbridge", "section_idx": 1, "section_name": "Arts and entertainment", "target_page_ids": [ 41494753 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " Bonding (dental), a dental procedure in which a dentist applies a resin material to the tooth", "section_idx": 2, "section_name": "Other uses", "target_page_ids": [ 11525261 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Human bonding", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 3829592 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " Female bonding", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 8837864 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Male bonding", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 1009651 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Channel bonding (or modem bonding), an arrangement in which two or more network interfaces on a host computer are combined", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 1952952 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " NIC bonding, an alternate name for link aggregation", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 1952952 ], "anchor_spans": [ [ 36, 52 ] ] }, { "plaintext": " Electrical bonding, practice of connecting all metal objects in a room to protect from electric shock", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 3581021 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": " Bonding, a method for creating electric interconnects:", "section_idx": 3, "section_name": "See also", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Ball bonding, a method very similar to wire bonding", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 230318 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Chip bonding, a method of wiring some chips (also from different manufactures) together on die an integrated circuit", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 15367982 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Wire bonding, a method of making interconnections between a microchip and the outside world as part of semiconductor device fabrication", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 230283 ], "anchor_spans": [ [ 1, 13 ] ] } ]

[]

[]

[ { "plaintext": "A branch, sometimes called a ramus in botany, is a woody structural member connected to but not part of the central trunk of a tree (or sometimes a shrub). Large branches are known as boughs and small branches are known as twigs. The term twig often refers to a terminus, while bough refers only to branches coming directly from the trunk.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 4183, 593231, 18955875, 61708, 169193 ], "anchor_spans": [ [ 38, 44 ], [ 116, 121 ], [ 127, 131 ], [ 148, 153 ], [ 239, 243 ] ] }, { "plaintext": "Due to a broad range of species of trees, branches and twigs can be found in many different shapes and sizes. While branches can be nearly horizontal, vertical, or diagonal, the majority of trees have upwardly diagonal branches. A number of mathematical properties are associated with tree branchings; they are natural examples of fractal patterns in nature, and, as observed by Leonardo da Vinci, their cross-sectional areas closely follow the da Vinci branching rule.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 38773637, 349251, 10913, 18079, 1337370, 35659147 ], "anchor_spans": [ [ 139, 149 ], [ 164, 172 ], [ 331, 338 ], [ 379, 396 ], [ 404, 425 ], [ 445, 468 ] ] }, { "plaintext": "Because of the enormous quantity of branches in the world, there are a variety of names in English alone for them. In general however, unspecific words for a branch (such as rise) have been replaced by the word branch itself.", "section_idx": 1, "section_name": "Terminology", "target_page_ids": [ 8569916, 233963 ], "anchor_spans": [ [ 91, 98 ], [ 190, 198 ] ] }, { "plaintext": "A bough can also be called a limb or arm, and though these are arguably metaphors, both are widely accepted synonyms for bough.", "section_idx": 1, "section_name": "Terminology", "target_page_ids": [ 20518, 67396 ], "anchor_spans": [ [ 72, 80 ], [ 108, 115 ] ] }, { "plaintext": "A crotch or fork is an area where a trunk splits into two or more boughs.", "section_idx": 1, "section_name": "Terminology", "target_page_ids": [ 41838275 ], "anchor_spans": [ [ 12, 16 ] ] }, { "plaintext": "A twig is frequently referred to as a sprig as well, especially when it has been plucked. Other words for twig include branchlet, spray, and surcle, as well as the technical terms surculus and ramulus.", "section_idx": 1, "section_name": "Terminology", "target_page_ids": [ 169193 ], "anchor_spans": [ [ 2, 6 ] ] }, { "plaintext": "Branches found under larger branches can be called underbranches.", "section_idx": 1, "section_name": "Terminology", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Some branches from specific trees have their own names, such as osiers and withes or withies, which come from willows. Often trees have certain words which, in English, are naturally collocated, such as holly and mistletoe, which usually employ the phrase \"sprig of\" (as in, a \"sprig of mistletoe\"). Similarly, the branch of a cherry tree is generally referred to as a \"cherry branch\", while other such formations (i.e., \"acacia branch\" or \"orange branch\") carry no such alliance. A good example of this versatility is oak, which could be referred to as variously an \"oak branch\", an \"oaken branch\", a \"branch of oak\", or the \"branch of an oak tree\".", "section_idx": 1, "section_name": "Terminology", "target_page_ids": [ 11677633, 91983, 435356, 19119938, 70129, 54773, 2959226, 4984440, 39696 ], "anchor_spans": [ [ 85, 92 ], [ 110, 116 ], [ 183, 193 ], [ 203, 208 ], [ 213, 222 ], [ 327, 338 ], [ 422, 428 ], [ 441, 447 ], [ 519, 522 ] ] }, { "plaintext": "Once a branch has been cut or in any other way removed from its source, it is most commonly referred to as a stick, and a stick employed for some purpose (such as walking, spanking, or beating) is often called a rod. Thin, flexible sticks are called switches, wands, shrags, or vimina (singular vimen).", "section_idx": 1, "section_name": "Terminology", "target_page_ids": [ 33509, 50589, 310234, 582433 ], "anchor_spans": [ [ 163, 170 ], [ 172, 180 ], [ 185, 192 ], [ 250, 256 ] ] }, { "plaintext": "In Old English, there are numerous words for branch, including , , , and . ", "section_idx": 1, "section_name": "Terminology", "target_page_ids": [ 22667 ], "anchor_spans": [ [ 3, 14 ] ] }, { "plaintext": "There are also numerous descriptive words, such as (that is, something that has bled, or \"bloomed\", out), (literally \"little bough\"), (literally \"on growth\"), and (literally \"offspringing\"). Numerous other words for twigs and boughs abound, including , which still survives as the \"-toe\" in mistletoe.", "section_idx": 1, "section_name": "Terminology", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Latin words for branch are ramus or cladus. The second term is an affix found in other modern words such as cladodonts (prehistoric sharks with branched teeth) or cladogram.", "section_idx": 1, "section_name": "Terminology", "target_page_ids": [ 50089877, 48975 ], "anchor_spans": [ [ 108, 118 ], [ 163, 172 ] ] }, { "plaintext": " Basal shoot", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 5552783 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Plant stem", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 18952693 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " Root", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 56333 ], "anchor_spans": [ [ 1, 5 ] ] }, { "plaintext": " Shoot", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 51668 ], "anchor_spans": [ [ 1, 6 ] ] }, { "plaintext": " Stolon", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 1430910 ], "anchor_spans": [ [ 1, 7 ] ] }, { "plaintext": " Switch (corporal punishment)", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 582433 ], "anchor_spans": [ [ 1, 29 ] ] }, { "plaintext": " Trunk (botany)", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 593231 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Turion (botany)", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 1662256 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Twig", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 169193 ], "anchor_spans": [ [ 1, 5 ] ] }, { "plaintext": " Wand", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 349575 ], "anchor_spans": [ [ 1, 5 ] ] }, { "plaintext": "分枝 (生物学)", "section_idx": 3, "section_name": "References", "target_page_ids": [], "anchor_spans": [] } ]

[ "Plant_morphology" ]

[ "branchlet", "sprig" ]

[ { "plaintext": "Brewster's angle (also known as the polarization angle) is an angle of incidence at which light with a particular polarization is perfectly transmitted through a transparent dielectric surface, with no reflection. When unpolarized light is incident at this angle, the light that is reflected from the surface is therefore perfectly polarized. This special angle of incidence is named after the Scottish physicist Sir David Brewster (1781–1868).", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 48934192, 17939, 41564, 41026, 521267, 8487 ], "anchor_spans": [ [ 62, 80 ], [ 90, 95 ], [ 114, 126 ], [ 174, 184 ], [ 202, 212 ], [ 413, 431 ] ] }, { "plaintext": "When light encounters a boundary between two media with different refractive indices, some of it is usually reflected as shown in the figure above. The fraction that is reflected is described by the Fresnel equations, and depends on the incoming light's polarization and angle of incidence.", "section_idx": 1, "section_name": "Explanation", "target_page_ids": [ 1553317, 25880, 11149 ], "anchor_spans": [ [ 45, 50 ], [ 66, 84 ], [ 199, 216 ] ] }, { "plaintext": "The Fresnel equations predict that light with the p polarization (electric field polarized in the same plane as the incident ray and the surface normal at the point of incidence) will not be reflected if the angle of incidence is ", "section_idx": 1, "section_name": "Explanation", "target_page_ids": [ 41092, 84029, 3364761, 173224 ], "anchor_spans": [ [ 66, 80 ], [ 103, 108 ], [ 116, 128 ], [ 137, 151 ] ] }, { "plaintext": "where n1 is the refractive index of the initial medium through which the light propagates (the \"incident medium\"), and n2 is the index of the other medium. This equation is known as Brewster's law, and the angle defined by it is Brewster's angle.", "section_idx": 1, "section_name": "Explanation", "target_page_ids": [ 25880 ], "anchor_spans": [ [ 16, 32 ] ] }, { "plaintext": "The physical mechanism for this can be qualitatively understood from the manner in which electric dipoles in the media respond to p-polarized light. One can imagine that light incident on the surface is absorbed, and then re-radiated by oscillating electric dipoles at the interface between the two media. The polarization of freely propagating light is always perpendicular to the direction in which the light is travelling. The dipoles that produce the transmitted (refracted) light oscillate in the polarization direction of that light. These same oscillating dipoles also generate the reflected light. However, dipoles do not radiate any energy in the direction of the dipole moment. If the refracted light is p-polarized and propagates exactly perpendicular to the direction in which the light is predicted to be specularly reflected, the dipoles point along the specular reflection direction and therefore no light can be reflected. (See diagram, above)", "section_idx": 1, "section_name": "Explanation", "target_page_ids": [ 8378, 30876071, 679297 ], "anchor_spans": [ [ 98, 104 ], [ 673, 686 ], [ 818, 838 ] ] }, { "plaintext": "With simple geometry this condition can be expressed as", "section_idx": 1, "section_name": "Explanation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "where θ1 is the angle of reflection (or incidence) and θ2 is the angle of refraction.", "section_idx": 1, "section_name": "Explanation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Using Snell's law,", "section_idx": 1, "section_name": "Explanation", "target_page_ids": [ 42964 ], "anchor_spans": [ [ 6, 17 ] ] }, { "plaintext": "one can calculate the incident angle at which no light is reflected:", "section_idx": 1, "section_name": "Explanation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Solving for θB gives", "section_idx": 1, "section_name": "Explanation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "For a glass medium () in air (), Brewster's angle for visible light is approximately 56°, while for an air-water interface (), it is approximately 53°. Since the refractive index for a given medium changes depending on the wavelength of light, Brewster's angle will also vary with wavelength.", "section_idx": 1, "section_name": "Explanation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The phenomenon of light being polarized by reflection from a surface at a particular angle was first observed by Étienne-Louis Malus in 1808. He attempted to relate the polarizing angle to the refractive index of the material, but was frustrated by the inconsistent quality of glasses available at that time. In 1815, Brewster experimented with higher-quality materials and showed that this angle was a function of the refractive index, defining Brewster's law.", "section_idx": 1, "section_name": "Explanation", "target_page_ids": [ 168115 ], "anchor_spans": [ [ 113, 132 ] ] }, { "plaintext": "Brewster's angle is often referred to as the \"polarizing angle\", because light that reflects from a surface at this angle is entirely polarized perpendicular to the plane of incidence (\"s-polarized\"). A glass plate or a stack of plates placed at Brewster's angle in a light beam can, thus, be used as a polarizer. The concept of a polarizing angle can be extended to the concept of a Brewster wavenumber to cover planar interfaces between two linear bianisotropic materials. In the case of reflection at Brewster's angle, the reflected and refracted rays are mutually perpendicular.", "section_idx": 1, "section_name": "Explanation", "target_page_ids": [ 24163057, 2722105, 17787631 ], "anchor_spans": [ [ 165, 183 ], [ 303, 312 ], [ 450, 472 ] ] }, { "plaintext": "For magnetic materials, Brewster's angle can exist for only one of the incident wave polarizations, as determined by the relative strengths of the dielectric permittivity and magnetic permeability. This has implications for the existence of generalized Brewster angles for dielectric metasurfaces.", "section_idx": 1, "section_name": "Explanation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "While at the Brewster angle there is no reflection of the p polarization, at yet greater angles the reflection coefficient of the p polarization is always less than that of the s polarization, almost up to 90° incidence where the reflectivity of each rises towards unity. Thus reflected light from horizontal surfaces (such as the surface of a road) at a distance much greater than ones height (so that the incidence angle of specularly reflected light is near, or usually well beyond the Brewster angle) is strongly s-polarized. Polarized sunglasses use a sheet of polarizing material to block horizontally-polarized light and thus reduce glare in such situations. These are most effective with smooth surfaces where specular reflection (thus from light whose angle of incidence is the same as the angle of reflection defined by the angle observed from) is dominant, but even diffuse reflections from roads for instance, are also significantly reduced.", "section_idx": 2, "section_name": "Applications", "target_page_ids": [ 11149, 41564, 2722105, 7497745, 679297, 48934192, 679294 ], "anchor_spans": [ [ 100, 122 ], [ 530, 550 ], [ 566, 585 ], [ 640, 645 ], [ 718, 737 ], [ 761, 779 ], [ 877, 895 ] ] }, { "plaintext": "Photographers also use polarizing filters to remove reflections from water so that they can photograph objects beneath the surface. Using a polarizing camera attachment which can be rotated, such a filter can be adjusted to reduce reflections from objects other than horizontal surfaces, such as seen in the accompanying photograph (right) where the s polarization (approximately vertical) has been eliminated using such a filter.", "section_idx": 2, "section_name": "Applications", "target_page_ids": [ 3248054 ], "anchor_spans": [ [ 140, 168 ] ] }, { "plaintext": "When recording a classical hologram, the bright reference beam is typically arranged to strike the film in the p polarization at Brewster's angle. By thus eliminating reflection of the reference beam at the transparent back surface of the holographic film, unwanted interference effects in the resulting hologram are avoided.", "section_idx": 2, "section_name": "Applications", "target_page_ids": [ 66338 ], "anchor_spans": [ [ 27, 35 ] ] }, { "plaintext": "Entrance windows or prisms with their surfaces at the Brewster angle are commonly used in optics and laser physics in particular. The polarized laser light enters the prism at Brewster's angle without any reflective losses.", "section_idx": 2, "section_name": "Applications", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "In surface science, Brewster angle microscopes are used to image layers of particles or molecules at air-liquid interfaces. Using illumination by a laser at Brewster's angle to the interface and observation at the angle of reflection, the uniform liquid does not reflect, appearing black in the image. However any molecular layers or artifacts at the surface, whose refractive index or physical structure contrasts with the liquid, allows for some reflection against that black background which is captured by a camera.", "section_idx": 2, "section_name": "Applications", "target_page_ids": [ 37188422 ], "anchor_spans": [ [ 20, 45 ] ] }, { "plaintext": "Gas lasers using an external cavity (reflection by one or both mirrors outside the gain medium) generally seal the tube using windows tilted at Brewster's angle. This prevents light in the intended polarization from being lost through reflection (and reducing the round-trip gain of the laser) which is critical in lasers having a low round-trip gain. On the other hand it does remove s polarized light, increasing the round trip loss for that polarization, and insuring the laser only oscillates in one linear polarization, as is usually desired. And many sealed-tube lasers (which don't even need windows) have a glass plate inserted within the tube at the Brewster angle, simply for the purpose of allowing lasing in only one polarization.", "section_idx": 2, "section_name": "Applications", "target_page_ids": [ 1193370, 591513, 40692 ], "anchor_spans": [ [ 0, 9 ], [ 29, 35 ], [ 83, 94 ] ] }, { "plaintext": "When the reflecting surface is absorbing, reflectivity at parallel polarization (p) goes through a non-zero minimum at the so-called pseudo-Brewster's angle.", "section_idx": 3, "section_name": "Pseudo-Brewster's angle", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Brewster angle microscope", "section_idx": 4, "section_name": "See also", "target_page_ids": [ 37188422 ], "anchor_spans": [ [ 1, 26 ] ] }, { "plaintext": " Brewster's Angle Extraction from Wolfram Research", "section_idx": 7, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Brewster window at RP-photonics.com", "section_idx": 7, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " TE, TM Reflection Coefficients – interactive phase and magnitude plots showing Brewster's angle", "section_idx": 7, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] } ]

[ "Geometrical_optics", "Physical_optics", "Angle", "Polarization_(waves)" ]

[ "Brewster angle" ]

[ { "plaintext": "Bridging loss is the loss, at a given frequency, that results when an impedance is connected across a transmission line. It is expressed as the ratio, in decibels, of the signal power delivered to a given point in a system downstream from the bridging point prior to bridging, to the signal power delivered to the given point after bridging. The term is introduced because return loss is not applicable to the high-impedance input conditions. The term is also used in telephone practice and synonymous with the insertion loss that result from bridging an impedance across a circuit.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 10779, 41957, 41811, 8410, 275871, 24236, 8286675, 346001 ], "anchor_spans": [ [ 38, 47 ], [ 70, 79 ], [ 102, 119 ], [ 154, 161 ], [ 171, 177 ], [ 178, 183 ], [ 216, 222 ], [ 574, 581 ] ] }, { "plaintext": "Source: from Federal Standard 1037C and from MIL-STD-188", "section_idx": 1, "section_name": "References", "target_page_ids": [ 37310, 41882 ], "anchor_spans": [ [ 13, 35 ], [ 45, 56 ] ] } ]

[ "Electrical_parameters" ]

[]

[ { "plaintext": "Brightness is an attribute of visual perception in which a source appears to be radiating or reflecting light. In other words, brightness is the perception elicited by the luminance of a visual target. The perception is not linear to luminance, and relies on the context of the viewing environment (for example, see White's illusion).", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 21280496, 17939, 25140, 18365, 1904601 ], "anchor_spans": [ [ 30, 47 ], [ 104, 109 ], [ 145, 155 ], [ 172, 181 ], [ 316, 332 ] ] }, { "plaintext": "Brightness is a subjective sensation of an object being observed and one of the color appearance parameters of many color appearance models, typically denoted as . Brightness refers to how much light appears to shine from something. This is a different perception than lightness, which is how light something appears compared to a similarly lit white object.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 46362605, 46362605, 9220187 ], "anchor_spans": [ [ 80, 107 ], [ 116, 138 ], [ 269, 278 ] ] }, { "plaintext": "The adjective bright derives from an Old English beorht with the same meaning via metathesis giving Middle English briht. The word is from a Common Germanic , ultimately from a PIE root with a closely related meaning, * \"white, bright\".", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 1271590, 202353, 559297 ], "anchor_spans": [ [ 50, 56 ], [ 142, 157 ], [ 178, 181 ] ] }, { "plaintext": "\"Brightness\" was formerly used as a synonym for the photometric term luminance and (incorrectly) for the radiometric term radiance. As defined by the US Federal Glossary of Telecommunication Terms (FS-1037C), \"brightness\" should now be used only for non-quantitative references to physiological sensations and perceptions of light.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 426889, 18365, 41625, 532592, 37310 ], "anchor_spans": [ [ 52, 63 ], [ 69, 78 ], [ 105, 116 ], [ 122, 130 ], [ 198, 206 ] ] }, { "plaintext": "With regard to stars, brightness is quantified as apparent magnitude and absolute magnitude.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 26808, 1962, 1963 ], "anchor_spans": [ [ 15, 19 ], [ 50, 68 ], [ 73, 91 ] ] }, { "plaintext": "Brightness is an antonym of dimness or dullness.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The United States Federal Trade Commission (FTC) has assigned an unconventional meaning to brightness when applied to lamps. When appearing on light bulb packages, brightness means luminous flux, while in other contexts it means luminance. Luminous flux is the total amount of light coming from a source, such as a lighting device. Luminance, the original meaning of brightness, is the amount of light per solid angle coming from an area, such as the sky. The table below shows the standard ways of indicating the amount of light.", "section_idx": 1, "section_name": "New meaning", "target_page_ids": [ 182215, 9656, 581888 ], "anchor_spans": [ [ 18, 42 ], [ 118, 123 ], [ 182, 195 ] ] }, { "plaintext": " Brightness (sound)", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 77892 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": " Luma (video)", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 6928954 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Luminance (relative)", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 3181148 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Luminosity", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 44790 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " The difference between luminescence and brightness is practically exploited by prism lighting", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 55528050 ], "anchor_spans": [ [ 80, 94 ] ] }, { "plaintext": " Poynton's Color FAQ", "section_idx": 4, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Világosság", "section_idx": 4, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] } ]

[ "Vision", "Photometry" ]

[ "bright", "lightfulness" ]

[ { "plaintext": "Buffer may refer to:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Buffer gas, an inert or nonflammable gas", "section_idx": 1, "section_name": "Science", "target_page_ids": [ 752897 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " Buffer solution, a solution used to prevent changes in pH", "section_idx": 1, "section_name": "Science", "target_page_ids": [ 46999 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Buffering agent, the weak acid or base in a buffer solution", "section_idx": 1, "section_name": "Science", "target_page_ids": [ 46999 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Lysis buffer, in cell biology", "section_idx": 1, "section_name": "Science", "target_page_ids": [ 505110 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Metal ion buffer", "section_idx": 1, "section_name": "Science", "target_page_ids": [ 41929942 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Mineral redox buffer, in geology", "section_idx": 1, "section_name": "Science", "target_page_ids": [ 7451913 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Buffer (GIS), a HASS zone around a map feature", "section_idx": 2, "section_name": "Technology and engineering", "target_page_ids": [ 18583225 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Buffer (optical fiber), a GG component of a fiber optic cable", "section_idx": 2, "section_name": "Technology and engineering", "target_page_ids": [ 3607894 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": " Buffer (rail transport), a device that cushions impacts between vehicles", "section_idx": 2, "section_name": "Technology and engineering", "target_page_ids": [ 2806112 ], "anchor_spans": [ [ 1, 24 ] ] }, { "plaintext": " Buffer amplifier, an isolating circuit used in electronics or telecommunications", "section_idx": 2, "section_name": "Technology and engineering", "target_page_ids": [ 429442 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Buffer stop, a device that keeps rail vehicles on tracks", "section_idx": 2, "section_name": "Technology and engineering", "target_page_ids": [ 1847431 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Buffer wheel, a device used to smooth a workpiece's surface", "section_idx": 2, "section_name": "Technology and engineering", "target_page_ids": [ 5757742 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Digital buffer, an electronic circuit used to isolate the input from the output", "section_idx": 2, "section_name": "Technology and engineering", "target_page_ids": [ 43440252 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Floor buffer, an appliance used to polish hard floors", "section_idx": 2, "section_name": "Technology and engineering", "target_page_ids": [ 31429619 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Optical buffer, a device that stores optically transmitted data", "section_idx": 2, "section_name": "Technology and engineering", "target_page_ids": [ 3500704 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Recoil buffer, a firearm component", "section_idx": 2, "section_name": "Technology and engineering", "target_page_ids": [ 3607610 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " Seismic buffers, protect structures against the effects of earthquakes", "section_idx": 2, "section_name": "Technology and engineering", "target_page_ids": [ 2111048 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Buffer (application), a software application for managing social network accounts", "section_idx": 3, "section_name": "Computing", "target_page_ids": [ 39112296 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Data buffer, memory used temporarily to store output or input data while it is transferred.", "section_idx": 3, "section_name": "Computing", "target_page_ids": [ 2406183 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Framebuffer, a type of data buffer for use in graphical display", "section_idx": 3, "section_name": "Computing", "target_page_ids": [ 149963 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Memory buffer register, the connection between processor and memory", "section_idx": 3, "section_name": "Computing", "target_page_ids": [ 1179426 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": " Bruce Buffer (born 1957), American sports announcer for UFC events", "section_idx": 4, "section_name": "People", "target_page_ids": [ 3584182 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Michael Buffer (born 1944), American ring announcer for boxing and wrestling events", "section_idx": 4, "section_name": "People", "target_page_ids": [ 715217 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Buffer (navy), a colloquial title", "section_idx": 5, "section_name": "Other uses", "target_page_ids": [ 8274330 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " Buffer state, a country separating two rival or hostile powers, thought to prevent conflict between them", "section_idx": 5, "section_name": "Other uses", "target_page_ids": [ 1030860 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Buffer zone, a region separating two areas, possibly to segregate or conjoin them", "section_idx": 5, "section_name": "Other uses", "target_page_ids": [ 489870 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Buffering (horse), an Australian thoroughbred", "section_idx": 5, "section_name": "Other uses", "target_page_ids": [ 49994430 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Buffering (TV series), a British TV series", "section_idx": 5, "section_name": "Other uses", "target_page_ids": [ 68484319 ], "anchor_spans": [ [ 1, 22 ] ] }, { "plaintext": " Buff (disambiguation)", "section_idx": 6, "section_name": "See also", "target_page_ids": [ 25764051 ], "anchor_spans": [ [ 1, 22 ] ] } ]

[]

[]

[ { "plaintext": "In a packet switched network, burst switching is a capability in which each network switch extracts routing instructions from an incoming packet header to establish and maintain the appropriate switch connection for the duration of the packet, following which the connection is automatically released. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 43339, 4122592, 40614, 25750, 43734, 472401, 346001 ], "anchor_spans": [ [ 5, 20 ], [ 21, 28 ], [ 76, 90 ], [ 100, 107 ], [ 138, 144 ], [ 145, 151 ], [ 201, 211 ] ] }, { "plaintext": "In concept, burst switching is similar to connectionless mode transmission, but differs in that burst switching implies an intent to establish the switch connection in near real time so that only minimum buffering is required at the node switch.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 40950, 25767, 998116 ], "anchor_spans": [ [ 42, 74 ], [ 168, 182 ], [ 233, 237 ] ] }, { "plaintext": "A variant of burst switching used in optical networks is optical burst switching.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 164174, 1696362 ], "anchor_spans": [ [ 37, 53 ], [ 57, 80 ] ] }, { "plaintext": "Source: from Federal Standard 1037C.", "section_idx": 1, "section_name": "References", "target_page_ids": [ 37310 ], "anchor_spans": [ [ 13, 35 ] ] } ]

[ "Computer_networks" ]

[]

[ { "plaintext": "In telecommunication, a burst transmission or data burst is the broadcast of a relatively high-bandwidth transmission over a short period. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374 ], "anchor_spans": [ [ 3, 20 ] ] }, { "plaintext": "Burst transmission can be intentional, broadcasting a compressed message at a very high data signaling rate within a very short transmission time.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 40998 ], "anchor_spans": [ [ 88, 107 ] ] }, { "plaintext": "In the 1980s, the term \"data burst\" (and \"info burst\") was used for a technique used by some United Kingdom and South African TV programmes to transmit large amounts of primarily textual information. They would display multiple pages of text in rapid succession, usually at the end of the programme; viewers would videotape it and then read it later by playing it back using the pause button after each page.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 31717 ], "anchor_spans": [ [ 93, 107 ] ] }, { "plaintext": "Data bursts can occur naturally, such as when the download of data from the internet briefly experiences higher speeds. It can also occur in a computer network where data transmission is interrupted at intervals. Burst transmission enables communications between data terminal equipment (DTEs) and a data network operating at dissimilar data signaling rates.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 14539, 4122592, 42168, 33094374, 74041 ], "anchor_spans": [ [ 76, 84 ], [ 143, 159 ], [ 166, 183 ], [ 240, 254 ], [ 263, 286 ] ] }, { "plaintext": "Burst mode (computing)", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 7076593 ], "anchor_spans": [ [ 0, 22 ] ] }, { "plaintext": "Iridium Short Burst Data", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 53008 ], "anchor_spans": [ [ 0, 24 ] ] }, { "plaintext": "Spread spectrum", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 41734 ], "anchor_spans": [ [ 0, 15 ] ] } ]

[ "Automatic_identification_and_data_capture", "Radio-frequency_identification" ]

[]

[ { "plaintext": "A busy signal is information communicated to a user or apparatus attempting a connection, indicating the requested connection cannot be completed.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 349973 ], "anchor_spans": [ [ 2, 13 ] ] }, { "plaintext": "Busy Signal (born 1982), or Reanno Gordon, a dancehall singer from Jamaica", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 16031574 ], "anchor_spans": [ [ 0, 11 ] ] }, { "plaintext": "\"Busy Signal\", a song by Prefuse 73 from the 2003 album One Word Extinguisher", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 1494538 ], "anchor_spans": [ [ 56, 77 ] ] } ]

[]

[]

[ { "plaintext": "Bypass may refer to:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Bypass (road), a road that avoids a built-up area (not to be confused with passing lane)", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 3220876 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " Flood bypass of a river", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 5561097 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Bypass surgery, a class of surgeries including for example:", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 1308737 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Heart bypass", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 195248 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Gastric bypass", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 781984 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Cardiopulmonary bypass", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 261827 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": " Bypass capacitor, used to bypass a power supply or other high impedance component", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 4397993 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " High bypass, a turbofan aircraft gas turbine engine", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 483048 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Bypass duct", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 103077 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Bypass ratio", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 483048 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Bleach bypass, an optical effect", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 1234472 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " Bypass (telecommunications)", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 3220883 ], "anchor_spans": [ [ 1, 28 ] ] }, { "plaintext": " Bypass valve", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " A blowoff valve on a compressor", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 906090 ], "anchor_spans": [ [ 3, 16 ] ] }, { "plaintext": " A manual gas addition valve on a rebreather", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 294126 ], "anchor_spans": [ [ 3, 28 ] ] }, { "plaintext": " The Bypass, a 2003 short silent Bollywood film", "section_idx": 2, "section_name": "Other uses", "target_page_ids": [ 50865220 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " Railroad bypass, a new railroad line built to replace or supplement an existing route", "section_idx": 2, "section_name": "Other uses", "target_page_ids": [ 37815041 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Pass (disambiguation)", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 374635 ], "anchor_spans": [ [ 1, 22 ] ] } ]

[]

[]

[ { "plaintext": "In telecommunication, a cable television relay service station (CARS) is a fixed or mobile station used for the transmission of television and related audio signals, signals of standard and FM broadcast stations, signals of instructional television fixed stations, and cablecasting from the point of reception to a terminal point from which the signals are distributed to the public.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 609152, 29831, 460792 ], "anchor_spans": [ [ 3, 20 ], [ 112, 124 ], [ 128, 138 ], [ 315, 323 ] ] }, { "plaintext": "Source: from Federal Standard 1037C and from the Code of Federal Regulations, Telecommunications Parts 0-199", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 37310, 53687 ], "anchor_spans": [ [ 13, 35 ], [ 49, 96 ] ] } ]

[ "Broadcasting" ]

[]

[ { "plaintext": "Call or Calls may refer to:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Call, a type of betting in poker", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 75691 ], "anchor_spans": [ [ 17, 33 ] ] }, { "plaintext": " Call, in the game of contract bridge, a bid, pass, double, or redouble in the bidding stage", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 3995 ], "anchor_spans": [ [ 22, 37 ] ] }, { "plaintext": " Call (band), from Lahore, Pakistan", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 6281082 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Call, a command in square dancing, delivered by a caller", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 890709 ], "anchor_spans": [ [ 51, 57 ] ] }, { "plaintext": " \"Call / I4U\", a 2011 single by Japanese music group AAA", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 36496658 ], "anchor_spans": [ [ 2, 12 ] ] }, { "plaintext": " \"Call\", a 2002 song by Ashanti from her album Ashanti", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 1273334 ], "anchor_spans": [ [ 47, 54 ] ] }, { "plaintext": " \"Call\" (Stray Kids song), 2021", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 68685208 ], "anchor_spans": [ [ 1, 25 ] ] }, { "plaintext": " Call (film), or The Call, 2020 South Korean film", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 60523254 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Calls (film), 2021 Indian Tamil-language crime thriller film", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 66896021 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Calls (TV series), a mystery thriller TV series on Apple TV+", "section_idx": 1, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 57759199 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Call on shares, a request for a further payment on partly paid share capital", "section_idx": 2, "section_name": "Finance", "target_page_ids": [ 36954291 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Call option, a term in stock trading", "section_idx": 2, "section_name": "Finance", "target_page_ids": [ 204251 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Call, a shell command in DOS, OS/2 and Microsoft Windows command-line interpreters", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 215461 ], "anchor_spans": [ [ 15, 22 ] ] }, { "plaintext": " Call, a method of starting a subroutine", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 32177451 ], "anchor_spans": [ [ 30, 40 ] ] }, { "plaintext": " Computer-assisted language learning, a concept in language education", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 194053 ], "anchor_spans": [ [ 1, 36 ] ] }, { "plaintext": " System call, in computer science, the mechanism used by an application program to request service from the operating system or another application program", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 102908 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Animal communication, a song or noise made by an animal such as:", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 464447 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Bird call, a type of bird vocalization", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 369978 ], "anchor_spans": [ [ 1, 10 ] ] }, { "plaintext": " Mating call, animal communication to attract a sexual partner", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 19251676 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Game call, a device that is used to animal communication noises to attract or drive animals to a hunter", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 384000 ], "anchor_spans": [ [ 1, 10 ] ] }, { "plaintext": " Call, an attempt to set up a telecommunication circuit", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 346001 ], "anchor_spans": [ [ 30, 55 ] ] }, { "plaintext": " Call, in teletraffic engineering, a unit of traffic measurement", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 1536216 ], "anchor_spans": [ [ 10, 33 ] ] }, { "plaintext": " Call origination, in telephony", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 9078663 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Call sign, in broadcasting and radio communications, a unique designation for a transmitting station", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 2797722 ], "anchor_spans": [ [ 1, 10 ] ] }, { "plaintext": " Telephone call", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 406703 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Call (surname)", "section_idx": 4, "section_name": "Other uses", "target_page_ids": [ 33386229 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Religious calling", "section_idx": 4, "section_name": "Other uses", "target_page_ids": [ 22684908 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Call, Texas, a community in the south-central United States", "section_idx": 4, "section_name": "Other uses", "target_page_ids": [ 18723253 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " CALL, U.S. Army Center for Army Lessons Learned", "section_idx": 4, "section_name": "Other uses", "target_page_ids": [ 9125644 ], "anchor_spans": [ [ 7, 48 ] ] }, { "plaintext": " CALL, Center for Anglican Learning & Leadership at the Church Divinity School of the Pacific", "section_idx": 4, "section_name": "Other uses", "target_page_ids": [ 1978731 ], "anchor_spans": [ [ 56, 93 ] ] }, { "plaintext": " Caller (disambiguation)", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 890684 ], "anchor_spans": [ [ 1, 24 ] ] }, { "plaintext": " Calling (disambiguation)", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 22685449 ], "anchor_spans": [ [ 1, 25 ] ] }, { "plaintext": " The Call (disambiguation)", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 650047 ], "anchor_spans": [ [ 1, 26 ] ] } ]

[]

[]

[ { "plaintext": "In telecommunications, a call collision (commonly known as glare) is one of two things:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374 ], "anchor_spans": [ [ 3, 20 ] ] }, { "plaintext": "The contention that occurs when a terminal and data circuit-terminating equipment (DCE) specify the same communication channel at the same time to transfer a call request and handle an incoming call. When call collision occurs, the DCE proceeds with the call request and cancels the incoming call.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 13440885, 460792, 18985040, 346001, 41005, 156700, 30012, 1915393, 406703, 40898 ], "anchor_spans": [ [ 4, 14 ], [ 34, 42 ], [ 47, 51 ], [ 52, 59 ], [ 83, 86 ], [ 105, 126 ], [ 139, 143 ], [ 147, 155 ], [ 158, 162 ], [ 210, 219 ] ] }, { "plaintext": "The condition that occurs when a trunk or channel is seized at both ends simultaneously.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 593233 ], "anchor_spans": [ [ 33, 38 ] ] }, { "plaintext": "Glare can sometimes be experienced as trying to make a call out on a PBX, and instead being connected to an incoming call. This can happen at home too, if a call out is made at the exact second that a call is about to start ringing in.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 1017561 ], "anchor_spans": [ [ 69, 72 ] ] }, { "plaintext": "Multi-line hunting attempts to avoid glare by selecting circuits in opposite preference order so the highest numbered line, which is last choice for incoming calls, is first choice for outgoing calls, like so:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 13043131 ], "anchor_spans": [ [ 0, 18 ] ] }, { "plaintext": "With PRI circuits, the channel selection sequence is specified when the circuit is provisioned. Common practice is to have the PBX use descending channel selection, and the carrier to use ascending. Glare is not common on PRI circuits because the signalling is so fast, however it is not impossible (especially if there are subtle differences in the timers at either end, and the circuit is being used at near-capacity). The users will not experience a connection to an unexpected call (as would be the case with analog circuits), because glare causes protocol errors that generally prevent any sort of successful connection. Instead, one or both of the call attempts might fail, and ideally an error would appear in the logs (this depends on the logging capabilities of the systems at either end of the circuit). Glare is quite rare on PRI circuits, and can be difficult to troubleshoot.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 41578 ], "anchor_spans": [ [ 5, 8 ] ] }, { "plaintext": "For old, analog PBX trunks, glare can be reduced by using ground start signalling, which offers better answer and disconnect supervision. IE: Nortel BSP discouraged using loop start trunks for this and other reasons. Long Distance exchanges in the 1950s and 60s incorporated Glare Detectors to alleviate the problem.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 3883906, 3883890 ], "anchor_spans": [ [ 58, 70 ], [ 171, 181 ] ] } ]

[ "Teletraffic" ]

[]

[ { "plaintext": "In telecommunications, the term call duration has the following meanings: ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374 ], "anchor_spans": [ [ 3, 20 ] ] }, { "plaintext": " In telephone systems, the time between (a) the instant a circuit, i.e., off-hook condition at each end, is established between the call originator and the call receiver and (b) the instant the call originator or the call receiver terminates the call.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 30003, 30012, 346001, 41438, 406712 ], "anchor_spans": [ [ 4, 13 ], [ 27, 31 ], [ 58, 65 ], [ 73, 81 ], [ 132, 147 ] ] }, { "plaintext": " In data transmission, the duration of the information transfer phase of an information transfer transaction.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 42168, 47867, 24047 ], "anchor_spans": [ [ 4, 21 ], [ 43, 63 ], [ 64, 69 ] ] }, { "plaintext": "Source: from Federal Standard 1037C", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 37310 ], "anchor_spans": [ [ 13, 35 ] ] } ]

[ "Teletraffic" ]

[]

[ { "plaintext": "In telecommunication, a called-party camp-on is a communication system service feature that enables the system to complete an access attempt in spite of issuance of a user blocking signal. This is most often found in a switchboard system at a company. Instead of going to voicemail or simply sitting on hold until the line is free, this feature places you in a queue whereby the call will be put through as soon as the line clears.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 40925, 417914, 810183, 2052479, 254867 ], "anchor_spans": [ [ 3, 20 ], [ 50, 70 ], [ 71, 86 ], [ 126, 140 ], [ 167, 171 ], [ 272, 281 ] ] }, { "plaintext": "Systems that provide this feature monitor the busy user until the user blocking signal ends, and then proceed to complete the requested access. This feature permits holding an incoming telephone call until the called party is free.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 406703 ], "anchor_spans": [ [ 185, 199 ] ] } ]

[ "Telephone_service_enhanced_features" ]

[]

[ { "plaintext": "In telecommunication, the term call processing has the following meanings: ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374 ], "anchor_spans": [ [ 3, 20 ] ] }, { "plaintext": " The sequence of operations performed by a switching system from the acceptance of an incoming call through the final disposition of the call. See call control for a more complete description.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 26668156, 406703, 1519429 ], "anchor_spans": [ [ 43, 59 ], [ 95, 99 ], [ 147, 159 ] ] }, { "plaintext": " The series of steps and processes by which an organization automates the handling of telephone calls (usually incoming calls). Call processing in this sense may include the initial greeting of the call (perhaps time-of-day or other factor dependent) to routing the call based on dialed digits or lack thereof. The automated treatment may include routing the call to an Interactive Voice Response System (IVR), sending the call to a voice mail system, queuing the call, etc. or a combination of steps and real-time decisions. See also Automated attendant.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 162186, 254867, 995064 ], "anchor_spans": [ [ 372, 411 ], [ 435, 452 ], [ 538, 557 ] ] }, { "plaintext": " The end-to-end sequence of operations performed by a network from the instant a call attempt is initiated until the instant the call release is completed.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 46545, 6968491 ], "anchor_spans": [ [ 54, 61 ], [ 81, 93 ] ] }, { "plaintext": " In data transmission, the operations required to complete all three phases of an information transfer transaction.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 42168, 47867 ], "anchor_spans": [ [ 4, 21 ], [ 82, 102 ] ] }, { "plaintext": "\"Volume Call Processing\" is the handling of calls when there are far more incoming calls than can be answered by an individual or group of attendants.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Call control", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 1519429 ], "anchor_spans": [ [ 0, 12 ] ] }, { "plaintext": " Federal Standard 1037C", "section_idx": 2, "section_name": "References", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Call processing tips", "section_idx": 2, "section_name": "References", "target_page_ids": [], "anchor_spans": [] } ]

[ "Teletraffic" ]

[]

[ { "plaintext": "In telecommunication, a call-second is a unit used to measure communications traffic density, equivalent to one call with a duration of one second. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 5177, 43081 ], "anchor_spans": [ [ 3, 20 ], [ 62, 75 ], [ 77, 84 ] ] }, { "plaintext": "Traffic is measured independent of users. For example, one user making two 75-second calls is equivalent to two users each making one 75-second call, as each case produces 150 call-seconds of traffic. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 2052479 ], "anchor_spans": [ [ 59, 63 ] ] }, { "plaintext": "A CCS (centacall-second) is often used to describe 100 call-seconds, so 3600 call-seconds = 36 CCS = 1 call-hour. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "In a communication network, a trunk (link) can carry numerous concurrent calls by means of multiplexing. Hence a particular number of call-seconds can be carried in infinitely many ways as calls are established and cleared over time. For example, one call-hour could be one call for an hour or two (possibly concurrent) calls for half an hour each. Call-seconds give a measure of the average number of concurrent calls.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Offered load is defined as the traffic density per unit time, measured in erlangs. An erlang is defined as one call-hour per hour, or 3,600 call-seconds per hour.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 22451128, 10283 ], "anchor_spans": [ [ 0, 12 ], [ 74, 81 ] ] }, { "plaintext": "Hence, if one CCS is measured over a one-hour period, the offered load is 1/36 erlangs.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] } ]

[ "Units_of_measurement", "Telecommunications" ]

[]

[ { "plaintext": "In telecommunication, call-sign allocation plan is the table of allocation of international call sign series contained in the current edition of the International Telecommunication Union (ITU) Radio Regulations.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 187192, 2797722, 14836, 41058898 ], "anchor_spans": [ [ 3, 20 ], [ 64, 74 ], [ 92, 101 ], [ 149, 186 ], [ 193, 210 ] ] }, { "plaintext": "Note: In the table of allocation, the first two characters of each call sign (whether two letters or one number and one letter, in that order) identify the nationality of the station. In certain instances where the complete alphabetical block is allocated to a single nation, the first letter is sufficient for national identity. Individual assignments are made by appropriate national assignment authorities from the national allocation.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 11447629 ], "anchor_spans": [ [ 176, 183 ] ] }, { "plaintext": " North American call sign", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 355786 ], "anchor_spans": [ [ 1, 25 ] ] }, { "plaintext": " ITU prefix", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 15437 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " Airline codes", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 5116754 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": "Code of Federal Regulations, Telecommunications Parts 0-199", "section_idx": 2, "section_name": "References", "target_page_ids": [ 469120 ], "anchor_spans": [ [ 0, 27 ] ] } ]

[ "Call_signs" ]

[]

[ { "plaintext": "In telecommunication, call tracing is a procedure that permits an entitled user to be informed about the routing of data for an established connection, identifying the entire route from the origin to the destination.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 2052479, 25750, 18985040, 26668156 ], "anchor_spans": [ [ 3, 20 ], [ 75, 79 ], [ 105, 112 ], [ 116, 120 ], [ 140, 150 ] ] }, { "plaintext": "There are two types of call tracing. Permanent call tracing permits tracing of all calls. On-demand call tracing permits tracing, upon request, of a specific call, provided that the called party dials a designated code immediately after the call to be traced is disconnected.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 406703 ], "anchor_spans": [ [ 23, 27 ] ] }, { "plaintext": " Call tracing - ATIS Telecom Glossary 2007 ", "section_idx": 1, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] } ]

[ "Telephony" ]

[]

[ { "plaintext": "In telecommunication, the term camp-on busy signal has the following meanings: ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374 ], "anchor_spans": [ [ 3, 20 ] ] }, { "plaintext": "A signal that informs a busy telephone user that another call originator is waiting for a connection. Synonym: call waiting", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 30003, 2052479, 406712, 346001, 406812 ], "anchor_spans": [ [ 29, 38 ], [ 39, 43 ], [ 57, 72 ], [ 90, 100 ], [ 111, 123 ] ] }, { "plaintext": "A teleprinter exchange facility signal that automatically causes a calling station to retry the call-receiver number after a given interval when the call-receiver teleprinter is occupied or the circuits are busy. Synonym: speed-up tone", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 31247, 26668156, 41132 ], "anchor_spans": [ [ 2, 13 ], [ 14, 22 ], [ 23, 31 ] ] } ]

[ "Telephony_signals", "Telegrams" ]

[]

[ { "plaintext": "In telecommunication, the term cancel character has the following meanings: ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374 ], "anchor_spans": [ [ 3, 20 ] ] }, { "plaintext": "A control character (\"CAN\", \"Cancel\", U+0018, or ^X) used to indicate that the data with which it is associated are in error or are to be disregarded. Exact meaning can depend on protocol. For example:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 5298, 31742, 2265038, 18985040, 41118 ], "anchor_spans": [ [ 2, 19 ], [ 38, 44 ], [ 49, 51 ], [ 79, 83 ], [ 119, 124 ] ] }, { "plaintext": " In some journalistic text transmission formats, it signifies that the preceding word should be deleted; it is sometimes called \"Kill Word\" (\"KW\") in this context.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " In some Videotex formats, it stops any running macros. In others, it clears the current line after the cursor position (compare ).", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 112882 ], "anchor_spans": [ [ 9, 17 ] ] }, { "plaintext": "A control character (\"CCH\", \"Cancel Character\", U+0094, or ) used to erase the previous character. This character was created as an unambiguous alternative to the much more common backspace character (\"BS\", U+0008), which has a now mostly obsolete alternative function of causing the following character to be superimposed on the preceding one.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 5298, 31742, 31742 ], "anchor_spans": [ [ 2, 19 ], [ 48, 54 ], [ 207, 213 ] ] } ]

[ "Control_characters" ]

[ "U+0094", "CANCEL CHARACTER", "CCH" ]

[ { "plaintext": "Capacitive coupling is the transfer of energy within an electrical network or between distant networks by means of displacement current between circuit(s) nodes, induced by the electric field. This coupling can have an intentional or accidental effect.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 4249694, 9559, 555119, 4854350 ], "anchor_spans": [ [ 11, 19 ], [ 56, 74 ], [ 115, 135 ], [ 155, 160 ] ] }, { "plaintext": "In its simplest implementation, capacitive coupling is achieved by placing a capacitor between two nodes. Where analysis of many points in a circuit is carried out, the capacitance at each point and between points can be described in a matrix form.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 4932111, 140711 ], "anchor_spans": [ [ 77, 86 ], [ 237, 248 ] ] }, { "plaintext": "In analog circuits, a coupling capacitor is used to connect two circuits such that only the AC signal from the first circuit can pass through to the next while DC is blocked. This technique helps to isolate the DC bias settings of the two coupled circuits. Capacitive coupling is also known as AC coupling and the capacitor used for the purpose is also known as a DC-blocking capacitor.", "section_idx": 1, "section_name": "Use in analog circuits", "target_page_ids": [ 1665281, 42986, 47713, 2047311 ], "anchor_spans": [ [ 3, 17 ], [ 92, 94 ], [ 160, 162 ], [ 211, 218 ] ] }, { "plaintext": "A coupling capacitor's ability to prevent a DC load from interfering with an AC source is particularly useful in Class A amplifier circuits by preventing a 0 volt input being passed to a transistor with additional resistor biasing; creating continuous amplification.", "section_idx": 1, "section_name": "Use in analog circuits", "target_page_ids": [ 54005385 ], "anchor_spans": [ [ 113, 130 ] ] }, { "plaintext": "Capacitive coupling decreases the low frequency gain of a system containing capacitively coupled units. Each coupling capacitor along with the input electrical impedance of the next stage forms a high-pass filter and the sequence of filters results in a cumulative filter with a −3dB frequency that may be higher than those of each individual filter. See Impedance bridging.", "section_idx": 1, "section_name": "Use in analog circuits", "target_page_ids": [ 160518, 41957, 56486, 8410, 638234 ], "anchor_spans": [ [ 34, 47 ], [ 149, 169 ], [ 196, 212 ], [ 281, 283 ], [ 355, 373 ] ] }, { "plaintext": "Coupling capacitors can also introduce nonlinear distortion at low frequencies. This is not an issue at high frequencies because the voltage across the capacitor stays very close to zero. However, if a signal passing through the coupling capacitance has a frequency that is low relative to the RC cutoff frequency, voltages can develop across the capacitor, which for some capacitor types results in changes of capacitance, leading to distortion. This is avoided by choosing capacitor types that have low voltage coefficient, and by using large values that put the cutoff frequency far lower than the frequencies of the signal.", "section_idx": 1, "section_name": "Use in analog circuits", "target_page_ids": [ 41052, 40986 ], "anchor_spans": [ [ 49, 59 ], [ 299, 315 ] ] }, { "plaintext": "AC coupling is also widely used in digital circuits to transmit digital signals with a zero DC component, known as DC-balanced signals. DC-balanced waveforms are useful in communications systems, since they can be used over AC-coupled electrical connections to avoid voltage imbalance problems and charge accumulation between connected systems or components.", "section_idx": 2, "section_name": "Use in digital circuits", "target_page_ids": [ 2047311, 2047311 ], "anchor_spans": [ [ 92, 104 ], [ 115, 126 ] ] }, { "plaintext": "For this reason, most modern line codes are designed to produce DC-balanced waveforms. The most common classes of DC-balanced line codes are constant-weight codes and paired-disparity codes.", "section_idx": 2, "section_name": "Use in digital circuits", "target_page_ids": [ 41317, 6934687, 41482 ], "anchor_spans": [ [ 29, 38 ], [ 141, 161 ], [ 167, 188 ] ] }, { "plaintext": "A gimmick loop is a simple type of capacitive coupler: two closely spaced strands of wire. It provides capacitive coupling of a few picofarads between two nodes. Usually the wires are twisted together.", "section_idx": 3, "section_name": "Gimmick loop", "target_page_ids": [ 8539679, 82355 ], "anchor_spans": [ [ 2, 14 ], [ 132, 141 ] ] }, { "plaintext": "Capacitive coupling is often unintended, such as the capacitance between two wires or PCB traces that are next to each other. One signal may capacitively couple with another and cause what appears to be noise. To reduce coupling, wires or traces are often separated as much as possible, or ground lines or ground planes are run in between signals that might affect each other, so that the lines capacitively couple to ground rather than each other. Prototypes of high-frequency (10s of MHz) or high-gain analog circuits, often use circuits that are built over a ground plane to control unwanted coupling. If a high-gain amplifier's output capacitively couples to its input it may become an electronic oscillator.", "section_idx": 4, "section_name": "Parasitic capacitive coupling", "target_page_ids": [ 65910, 3966982, 41218, 41968, 41968, 9931, 9920 ], "anchor_spans": [ [ 86, 89 ], [ 204, 209 ], [ 308, 320 ], [ 502, 506 ], [ 619, 623 ], [ 624, 633 ], [ 694, 715 ] ] }, { "plaintext": " Coupling (electronics)", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 4249694 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": " DC block", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 23267052 ], "anchor_spans": [ [ 1, 9 ] ] }, { "plaintext": " Decoupling (electronics)", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 34782809 ], "anchor_spans": [ [ 1, 25 ] ] }, { "plaintext": " Decoupling capacitor", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 4397993 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Direct coupling", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 5258912 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Differential capacitance", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 13774593 ], "anchor_spans": [ [ 1, 25 ] ] }, { "plaintext": " RC coupling", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 43139446 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Crosstalk", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 2995499 ], "anchor_spans": [ [ 1, 10 ] ] }, { "plaintext": "Howard Johnson: When to use AC coupling, DC Blocking Capacitor Value", "section_idx": 7, "section_name": "External links", "target_page_ids": [ 5890340 ], "anchor_spans": [ [ 0, 14 ] ] }, { "plaintext": "Texas Instruments: AC-Coupling Between Differential LVPECL, LVDS, HSTL, and CML (PDF)", "section_idx": 7, "section_name": "External links", "target_page_ids": [ 47768 ], "anchor_spans": [ [ 0, 17 ] ] } ]

[ "Capacitors", "Electromagnetic_compatibility" ]

[ "Capacitive coupling" ]

[ { "plaintext": "In a radio receiver, the capture effect, or FM capture effect, is a phenomenon associated with FM reception in which only the stronger of two signals at, or near, the same frequency or channel will be demodulated.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 491851, 10835, 10779, 66926 ], "anchor_spans": [ [ 5, 19 ], [ 95, 97 ], [ 172, 181 ], [ 201, 212 ] ] }, { "plaintext": "The capture effect is defined as the complete suppression of the weaker signal at the receiver's limiter (if present) where the weaker signal is not amplified, but attenuated. When both signals are nearly equal in strength or are fading independently, the receiver may rapidly switch from one to another and exhibit flutter.", "section_idx": 1, "section_name": "FM phenomenon", "target_page_ids": [ 495387, 9931, 40735, 81211, 41160 ], "anchor_spans": [ [ 97, 104 ], [ 149, 158 ], [ 164, 173 ], [ 231, 237 ], [ 317, 324 ] ] }, { "plaintext": "The capture effect can occur at the signal limiter, or in the demodulation stage for circuits that do not require a signal limiter. Some types of radio receiver circuits have a stronger capture effect than others. The measurement of how well a receiver rejects a second signal on the same frequency is called its capture ratio. It is measured as the lowest ratio of the power of two signals that will result in the suppression of the weaker signal. ", "section_idx": 1, "section_name": "FM phenomenon", "target_page_ids": [ 66926, 4529151 ], "anchor_spans": [ [ 62, 74 ], [ 146, 169 ] ] }, { "plaintext": "The capture effect phenomenon was first documented in 1938 by General Electric engineers conducting test transmissions. Two experimental FM stations, located 15 miles (24 km) apart in Albany and Schenectady, New York, were configured to transmit on the same frequency, in order to study how this would affect reception. It was determined that, for most of the path between the two stations, only one of the signals could be heard, with the complete elimination of the other. It was concluded that this effect occurred whenever the stronger signal was about twice as strong as the weaker one. This was significantly different than the case with amplitude modulation signals, where the general standard for broadcasting stations was that to avoid objectionable interference the stronger signal had to be about twenty times that of the weaker one. The capture effect thus allowed co-channel FM broadcasting stations to be located somewhat closer to each other than AM ones, without causing mutual interference.", "section_idx": 1, "section_name": "FM phenomenon", "target_page_ids": [ 12730 ], "anchor_spans": [ [ 62, 78 ] ] }, { "plaintext": "Amplitude modulation, or AM radio, transmission does not exhibit this effect. For AM reception, the receiver tracks the signal strength of the AM signal as the basis for demodulation. This allows signals to be tracked as just another change in amplitude, so it is possible for an AM receiver to demodulate several carriers at the same time, resulting in an audio mix.", "section_idx": 2, "section_name": "AM immunity", "target_page_ids": [ 113509, 609152 ], "anchor_spans": [ [ 25, 27 ], [ 35, 47 ] ] }, { "plaintext": "The ability to receive multiple signals simultaneously is in some cases considered beneficial and is one reason that the aviation industry, and others, have chosen to use AM rather than FM for communications. ", "section_idx": 2, "section_name": "AM immunity", "target_page_ids": [ 1416009 ], "anchor_spans": [ [ 121, 129 ] ] }, { "plaintext": "Phenomena similar to the capture effect are described in AM when offset carriers of different strengths are present in the passband of a receiver. For example, the aviation glideslope vertical guidance clearance beam is sometimes described as a \"capture effect\" system, even though it operates using AM signals.", "section_idx": 2, "section_name": "AM immunity", "target_page_ids": [ 48859505 ], "anchor_spans": [ [ 174, 184 ] ] }, { "plaintext": "For digital modulation schemes it has been shown that for properly implemented on-off keying/amplitude-shift keying systems, co-channel rejection can be better than for frequency-shift keying systems.", "section_idx": 3, "section_name": "Digital modulation", "target_page_ids": [ 20637, 1408014, 946426, 229454, 231538, 41193 ], "anchor_spans": [ [ 4, 22 ], [ 79, 92 ], [ 93, 115 ], [ 125, 135 ], [ 136, 145 ], [ 169, 191 ] ] }, { "plaintext": " Near–far problem", "section_idx": 4, "section_name": "See also", "target_page_ids": [ 1257591 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " FM Limiter & Capture Ratio, by Dietmar Rudolph", "section_idx": 7, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] } ]

[ "Radio", "Broadcast_engineering" ]

[]

[ { "plaintext": "Carrier may refer to:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Carrier (album), a 2013 album by The Dodos", "section_idx": 1, "section_name": "Entertainment", "target_page_ids": [ 39431579 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Carrier (game), a South Pacific World War II board game", "section_idx": 1, "section_name": "Entertainment", "target_page_ids": [ 1865553 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Carrier (TV series), a ten-part documentary miniseries that aired on PBS in April 2008", "section_idx": 1, "section_name": "Entertainment", "target_page_ids": [ 17154209 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " Carrier (video game), a 2000 video game for the Sega Dreamcast", "section_idx": 1, "section_name": "Entertainment", "target_page_ids": [ 2251164 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Carriers (film), a 2009 post-apocalyptic horror film", "section_idx": 1, "section_name": "Entertainment", "target_page_ids": [ 24013376 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " The Carrier (band), an American melodic hardcore band", "section_idx": 1, "section_name": "Entertainment", "target_page_ids": [ 29690898 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": " The Carrier, spaceship home to the Authority, a team of comic superheroes", "section_idx": 1, "section_name": "Entertainment", "target_page_ids": [ 638661 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Carrier is a diluent used to simplify radioanalytical separations.", "section_idx": 2, "section_name": "Science", "target_page_ids": [ 23568658 ], "anchor_spans": [ [ 1, 8 ] ] }, { "plaintext": " Carrier protein, a protein that facilitates the transport of another molecule", "section_idx": 2, "section_name": "Science", "target_page_ids": [ 529981 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Genetic carrier, an organism that has inherited a genetic trait or mutation", "section_idx": 2, "section_name": "Science", "target_page_ids": [ 16464479 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Asymptomatic carrier, an organism infected with an infectious disease agent", "section_idx": 2, "section_name": "Science", "target_page_ids": [ 679680 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Aircraft carrier, a warship primarily hosting fixed-wing aircraft", "section_idx": 3, "section_name": "Technology", "target_page_ids": [ 2219 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Carrier recovery in telecommunications", "section_idx": 3, "section_name": "Technology", "target_page_ids": [ 5768230 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Carrier signal, a waveform suitable for modulation by an information-bearing signal", "section_idx": 3, "section_name": "Technology", "target_page_ids": [ 153217 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Helicopter carrier, a warship primarily hosting helicopters", "section_idx": 3, "section_name": "Technology", "target_page_ids": [ 3598171 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": " Universal Carrier, a tracked vehicle", "section_idx": 3, "section_name": "Technology", "target_page_ids": [ 1414266 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Wireless carrier, an organization that operates a wireless network for mobile phones", "section_idx": 3, "section_name": "Technology", "target_page_ids": [ 481601 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Information carrier or substrate, the image in a photographic layer", "section_idx": 3, "section_name": "Technology", "target_page_ids": [ 5769249 ], "anchor_spans": [ [ 50, 68 ] ] }, { "plaintext": " Carrier, Oklahoma, a town in Garfield County, Oklahoma", "section_idx": 4, "section_name": "Other", "target_page_ids": [ 130194 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Carrier Global Corporation, air conditioning and commercial refrigeration manufacturing company", "section_idx": 4, "section_name": "Other", "target_page_ids": [ 2728694 ], "anchor_spans": [ [ 1, 27 ] ] }, { "plaintext": " Carrier language, the Athabaskan language of the Dakelh people", "section_idx": 4, "section_name": "Other", "target_page_ids": [ 2401265 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Carrier pigeon, a dove trained to transport messages", "section_idx": 4, "section_name": "Other", "target_page_ids": [ 206964 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Common carrier, an organization that transports a product or service", "section_idx": 4, "section_name": "Other", "target_page_ids": [ 40910 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " JMA Wireless Dome, formerly known as the Carrier Dome, in Syracuse, New York", "section_idx": 4, "section_name": "Other", "target_page_ids": [ 746715 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Mail carrier, a postal worker", "section_idx": 4, "section_name": "Other", "target_page_ids": [ 620851 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Disease carrier (disambiguation) in medicine", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 7290622 ], "anchor_spans": [ [ 1, 33 ] ] }, { "plaintext": " Pet carrier", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 23864252 ], "anchor_spans": [ [ 1, 12 ] ] } ]

[]

[]

[ { "plaintext": "Carrier-sense multiple access with collision avoidance (CSMA/CA) in computer networking, is a network multiple access method in which carrier sensing is used, but nodes attempt to avoid collisions by beginning transmission only after the channel is sensed to be \"idle\". When they do transmit, nodes transmit their packet data in its entirety.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 4122592, 86392, 153217, 998116 ], "anchor_spans": [ [ 68, 84 ], [ 102, 124 ], [ 134, 141 ], [ 163, 167 ] ] }, { "plaintext": "It is particularly important for wireless networks, where the alternative with collision detection CSMA/CD, is not possible due to wireless transmitters desensing (turning off) their receivers during packet transmission.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 40847 ], "anchor_spans": [ [ 99, 106 ] ] }, { "plaintext": "CSMA/CA is unreliable due to the hidden node problem.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 392874 ], "anchor_spans": [ [ 33, 52 ] ] }, { "plaintext": "CSMA/CA is a protocol that operates in the Data Link Layer (Layer 2) of the OSI model.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 152949, 22747 ], "anchor_spans": [ [ 43, 58 ], [ 76, 85 ] ] }, { "plaintext": "Collision avoidance is used to improve the performance of the CSMA method by attempting to divide the channel somewhat equally among all transmitting nodes within the collision domain.", "section_idx": 1, "section_name": "Details", "target_page_ids": [ 47083 ], "anchor_spans": [ [ 62, 66 ] ] }, { "plaintext": " Carrier Sense: prior to transmitting, a node first listens to the shared medium (such as listening for wireless signals in a wireless network) to determine whether another node is transmitting or not. Note that the hidden node problem means another node may be transmitting which goes undetected at this stage.", "section_idx": 1, "section_name": "Details", "target_page_ids": [ 392874 ], "anchor_spans": [ [ 216, 235 ] ] }, { "plaintext": " Collision Avoidance: if another node was heard, we wait for a period of time (usually random) for the node to stop transmitting before listening again for a free communications channel.", "section_idx": 1, "section_name": "Details", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Request to Send/Clear to Send (RTS/CTS) may optionally be used at this point to mediate access to the shared medium. This goes some way to alleviating the problem of hidden nodes because, for instance, in a wireless network, the Access Point only issues a Clear to Send to one node at a time. However, wireless 802.11 implementations do not typically implement RTS/CTS for all transmissions; they may turn it off completely, or at least not use it for small packets (the overhead of RTS, CTS and transmission is too great for small data transfers).", "section_idx": 1, "section_name": "Details", "target_page_ids": [ 14739 ], "anchor_spans": [ [ 312, 318 ] ] }, { "plaintext": " Transmission: if the medium was identified as being clear or the node received a CTS to explicitly indicate it can send, it sends the frame in its entirety. Unlike CSMA/CD, it is very challenging for a wireless node to listen at the same time as it transmits (its transmission will dwarf any attempt to listen). Continuing the wireless example, the node awaits receipt of an acknowledgement packet from the Access Point to indicate the packet was received and checksummed correctly. If such acknowledgement does not arrive in a timely manner, it assumes the packet collided with some other transmission, causing the node to enter a period of binary exponential backoff prior to attempting to re-transmit.", "section_idx": 1, "section_name": "Details", "target_page_ids": [ 40847, 1148272 ], "anchor_spans": [ [ 165, 172 ], [ 643, 669 ] ] }, { "plaintext": "Although CSMA/CA has been used in a variety of wired communication systems, it is particularly beneficial in a wireless LAN due to a common problem of multiple stations being able to see the Access Point, but not each other. This is due to differences in transmit power, and receive sensitivity, as well as distance, and location with respect to the AP. This will cause a station to not be able to 'hear' another station's broadcast. This is the so-called 'hidden node', or 'hidden station' problem. Devices utilizing 802.11 based standards can enjoy the benefits of collision avoidance (RTS / CTS handshake, also Point coordination function), although they do not do so by default. By default they use a Carrier sensing mechanism called 'exponential backoff' (or Distributed coordination function), that relies upon a station attempting to 'listen' for another station's broadcast before sending. CA, or PCF relies upon the AP (or the 'receiver' for Ad hoc networks) granting a station the exclusive right to transmit for a given period of time after requesting it (Request to Send / Clear to Send).", "section_idx": 1, "section_name": "Details", "target_page_ids": [ 33143, 392874, 14739, 1695464, 392839 ], "anchor_spans": [ [ 111, 123 ], [ 457, 468 ], [ 518, 524 ], [ 614, 641 ], [ 764, 797 ] ] }, { "plaintext": "CSMA-CA requires a determination of whether a channel is 'idle', even when incompatible standards and overlapping transmission frequencies are used. Per the standards, for 802.11/Wi-Fi transmitters on the same channel, transmitters must take turns to transmit if they can detect each other even 3dB above the noise floor (the thermal noise floor is around -101 dBm for 20MHz channels). On the other hand, transmitters will ignore transmitters with incompatible standards or on overlapping channels if the received signal strength from them is below a threshold Pth which, for non Wi-Fi 6 systems, is between -76 and -80 dBm.", "section_idx": 1, "section_name": "Details", "target_page_ids": [ 795170, 48971736 ], "anchor_spans": [ [ 309, 320 ], [ 580, 587 ] ] }, { "plaintext": "CSMA/CA can optionally be supplemented by the exchange of a Request to Send (RTS) packet sent by the sender S, and a Clear to Send (CTS) packet sent by the intended receiver R. Thus alerting all nodes within range of the sender, receiver or both, to not transmit for the duration of the main transmission. This is known as the IEEE 802.11 RTS/CTS exchange. Implementation of RTS/CTS helps to partially solve the hidden node problem that is often found in wireless networking.", "section_idx": 2, "section_name": "IEEE 802.11 RTS/CTS Exchange", "target_page_ids": [ 645941, 392874 ], "anchor_spans": [ [ 327, 346 ], [ 412, 431 ] ] }, { "plaintext": "CSMA/CA performance is based largely upon the modulation technique used to transmit the data between nodes. Studies show that under ideal propagation conditions (simulations), direct-sequence spread spectrum (DSSS) provides the highest throughput for all nodes on a network when used in conjunction with CSMA/CA and the IEEE 802.11 RTS/CTS exchange under light network load conditions. Frequency hopping spread spectrum (FHSS) follows distantly behind DSSS with regard to throughput with a greater throughput once network load becomes substantially heavy. However, the throughput is generally the same under real world conditions due to radio propagation factors.", "section_idx": 3, "section_name": "Performance", "target_page_ids": [ 41049, 46890 ], "anchor_spans": [ [ 176, 207 ], [ 386, 419 ] ] }, { "plaintext": " GNET – an early proprietary LAN protocol", "section_idx": 4, "section_name": "Usage", "target_page_ids": [ 17739 ], "anchor_spans": [ [ 29, 32 ] ] }, { "plaintext": " Apple's LocalTalk implemented CSMA/CA on an electrical bus using a three-byte jamming signal.", "section_idx": 4, "section_name": "Usage", "target_page_ids": [ 856, 54180 ], "anchor_spans": [ [ 1, 8 ], [ 9, 18 ] ] }, { "plaintext": " 802.11 RTS/CTS implements virtual carrier sensing using short request to send and clear to send messages for WLANs (802.11 mainly relies on physical carrier sensing though).", "section_idx": 4, "section_name": "Usage", "target_page_ids": [ 645941, 33143, 14739 ], "anchor_spans": [ [ 1, 15 ], [ 110, 114 ], [ 117, 123 ] ] }, { "plaintext": " IEEE 802.15.4 (Wireless PAN) uses CSMA/CA", "section_idx": 4, "section_name": "Usage", "target_page_ids": [ 455777 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " NCR WaveLAN – an early proprietary wireless network protocol", "section_idx": 4, "section_name": "Usage", "target_page_ids": [ 5718913 ], "anchor_spans": [ [ 5, 12 ] ] }, { "plaintext": " HomePNA", "section_idx": 4, "section_name": "Usage", "target_page_ids": [ 168417 ], "anchor_spans": [ [ 1, 8 ] ] }, { "plaintext": " Bus networks", "section_idx": 4, "section_name": "Usage", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " The ITU-T G.hn standard, which provides a way to create a high-speed (up to 1 Gigabit/s) local area network using existing home wiring (power lines, phone lines and coaxial cables), uses CSMA/CA as a channel access method for flows that do not require guaranteed quality of service, specifically the CSMA/CARP variant.", "section_idx": 4, "section_name": "Usage", "target_page_ids": [ 14744, 17216326, 17739, 238420, 17518144, 86392, 25315, 2112592 ], "anchor_spans": [ [ 5, 10 ], [ 11, 15 ], [ 90, 108 ], [ 137, 148 ], [ 166, 180 ], [ 201, 222 ], [ 264, 282 ], [ 301, 310 ] ] }, { "plaintext": " Carrier-sense multiple access", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 47083 ], "anchor_spans": [ [ 1, 30 ] ] }, { "plaintext": " Carrier-sense multiple access with collision detection", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 40847 ], "anchor_spans": [ [ 1, 55 ] ] }, { "plaintext": " CSMA/CARP", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 2112592 ], "anchor_spans": [ [ 1, 10 ] ] }, { "plaintext": " IEEE 802.11 RTS/CTS", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 645941 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " Network allocation vector", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 11775868 ], "anchor_spans": [ [ 1, 26 ] ] }, { "plaintext": " Truncated binary exponential backoff", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 1148272 ], "anchor_spans": [ [ 1, 37 ] ] }, { "plaintext": " Computer Networks: a Systems Approach. Peterson & Davie. Morgan Kaufmann, Burlington, MA, USA. . pp128–139", "section_idx": 6, "section_name": "References", "target_page_ids": [ 8306989 ], "anchor_spans": [ [ 58, 73 ] ] }, { "plaintext": " CSMA/CA RTS/CTS Simulation", "section_idx": 7, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Carrier sense multiple access", "section_idx": 7, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "载波侦听多路访问", "section_idx": 7, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] } ]

[ "IEEE_802.11" ]

[]

[ { "plaintext": "Carrier-sense multiple access with collision detection (CSMA/CD) is a medium access control (MAC) method used most notably in early Ethernet technology for local area networking. It uses carrier-sensing to defer transmissions until no other stations are transmitting. This is used in combination with collision detection in which a transmitting station detects collisions by sensing transmissions from other stations while it is transmitting a frame. When this collision condition is detected, the station stops transmitting that frame, transmits a jam signal, and then waits for a random time interval before trying to resend the frame.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 207472, 9499, 17739, 153217, 41172 ], "anchor_spans": [ [ 70, 91 ], [ 132, 140 ], [ 156, 174 ], [ 187, 194 ], [ 444, 449 ] ] }, { "plaintext": "CSMA/CD is a modification of pure carrier-sense multiple access (CSMA). CSMA/CD is used to improve CSMA performance by terminating transmission as soon as a collision is detected, thus shortening the time required before a retry can be attempted.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 47083 ], "anchor_spans": [ [ 34, 63 ] ] }, { "plaintext": "With the growing popularity of Ethernet switches in the 1990s, IEEE 802.3 deprecated Ethernet repeaters in 2011, making CSMA/CD and half-duplex operation less common and less important.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 40614, 14791, 1937926 ], "anchor_spans": [ [ 31, 46 ], [ 63, 73 ], [ 85, 102 ] ] }, { "plaintext": "The following procedure is used to initiate a transmission. The procedure is complete when the frame is transmitted successfully or a collision is detected during transmission.", "section_idx": 1, "section_name": "Procedure", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Is a frame ready for transmission? If not, wait for a frame.", "section_idx": 1, "section_name": "Procedure", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Is medium idle? If not, wait until it becomes ready.", "section_idx": 1, "section_name": "Procedure", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Start transmitting and monitor for collision during transmission.", "section_idx": 1, "section_name": "Procedure", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Did a collision occur? If so, go to collision detected procedure.", "section_idx": 1, "section_name": "Procedure", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Reset retransmission counters and complete frame transmission.", "section_idx": 1, "section_name": "Procedure", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The following procedure is used to resolve a detected collision. The procedure is complete when retransmission is initiated or the retransmission is aborted due to numerous collisions.", "section_idx": 1, "section_name": "Procedure", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Continue transmission (with a jam signal instead of frame header/data/CRC) until minimum packet time is reached to ensure that all receivers detect the collision.", "section_idx": 1, "section_name": "Procedure", "target_page_ids": [ 38838 ], "anchor_spans": [ [ 71, 74 ] ] }, { "plaintext": " Increment retransmission counter.", "section_idx": 1, "section_name": "Procedure", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Was the maximum number of transmission attempts reached? If so, abort transmission.", "section_idx": 1, "section_name": "Procedure", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Calculate and wait the random backoff period based on number of collisions.", "section_idx": 1, "section_name": "Procedure", "target_page_ids": [ 1148272 ], "anchor_spans": [ [ 31, 38 ] ] }, { "plaintext": " Re-enter main procedure at stage 1.", "section_idx": 1, "section_name": "Procedure", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Methods for collision detection are media dependent. On a shared, electrical bus such as 10BASE5 or 10BASE2, collisions can be detected by comparing transmitted data with received data or by recognizing a higher than normal signal amplitude on the bus. On all other media, a carrier sensed on the receive channel while transmitting triggers a collision event. Repeaters or hubs detect collisions on their own and propagate jam signals.", "section_idx": 1, "section_name": "Procedure", "target_page_ids": [ 35201, 35200, 1937926 ], "anchor_spans": [ [ 89, 96 ], [ 100, 107 ], [ 373, 377 ] ] }, { "plaintext": "The collision recovery procedure can be likened to what happens at a dinner party, where all the guests talk to each other through a common medium (the air). Before speaking, each guest politely waits for the current speaker to finish. If two guests start speaking at the same time, both stop and wait for short, random periods of time (in Ethernet, this time is measured in microseconds). The hope is that by each choosing a random period of time, both guests will not choose the same time to try to speak again, thus avoiding another collision.", "section_idx": 1, "section_name": "Procedure", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The jam signal or jamming signal is a signal that carries a 32-bit binary pattern sent by a data station to inform the other stations of the collision and that they must not transmit.", "section_idx": 2, "section_name": "Jam signal", "target_page_ids": [ 41703, 80733 ], "anchor_spans": [ [ 38, 44 ], [ 60, 66 ] ] }, { "plaintext": "The maximum jam-time is calculated as follows: The maximum allowed diameter of an Ethernet installation is limited to 232 bits. This makes a round-trip-time of 464 bits. As the slot time in Ethernet is 512 bits, the difference between slot time and round-trip-time is 48 bits (6 bytes), which is the maximum jam-time.", "section_idx": 2, "section_name": "Jam signal", "target_page_ids": [ 9499, 507138 ], "anchor_spans": [ [ 82, 90 ], [ 177, 186 ] ] }, { "plaintext": "This in turn means: A station noting a collision has occurred is sending a 4 to 6 byte long pattern composed of 16 1-0 bit combinations. Note: The size of this jam signal is clearly above the minimum allowed frame-size of 64 bytes.", "section_idx": 2, "section_name": "Jam signal", "target_page_ids": [ 7320527 ], "anchor_spans": [ [ 39, 48 ] ] }, { "plaintext": "The purpose of this is to ensure that any other node which may currently be receiving a frame will receive the jam signal in place of the correct 32-bit MAC CRC, this causes the other receivers to discard the frame due to a CRC error.", "section_idx": 2, "section_name": "Jam signal", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "A late collision is a type of collision that happens further into the packet than is allowed for by the protocol standard in question. In 10-megabit shared-medium Ethernet, if a collision error occurs after the first 512 bits of data are transmitted by the transmitting station, a late collision is said to have occurred. Importantly, late collisions are not re-sent by the NIC, unlike collisions occurring before the first 64 octets; it is left for the upper layers of the protocol stack to determine that there was loss of data.", "section_idx": 3, "section_name": "Late collision", "target_page_ids": [ 243613, 23882 ], "anchor_spans": [ [ 374, 377 ], [ 474, 488 ] ] }, { "plaintext": "As a correctly set up CSMA/CD network link should not have late collisions, the usual possible causes are full-duplex/half-duplex mismatch, exceeded Ethernet cable length limits, or defective hardware such as incorrect cabling, non-compliant number of hubs in the network, or a bad NIC.", "section_idx": 3, "section_name": "Late collision", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "A local collision is a collision that occurs at the NIC, as opposed to on the wire. A NIC cannot detect local collisions without attempting to send information.", "section_idx": 4, "section_name": "Local collision", "target_page_ids": [ 243613 ], "anchor_spans": [ [ 52, 55 ] ] }, { "plaintext": "On UTP cable, a local collision is detected on the local segment only when a station detects a signal on the RX pair at the same time it is sending on the TX pair. Since the two signals are on different pairs, there is no characteristic change in the signal. Collisions are only recognized on UTP when the station is operating in half-duplex. The only functional difference between half and full-duplex operation in this regard is whether or not the transmit and receive pairs are permitted to be used simultaneously.", "section_idx": 4, "section_name": "Local collision", "target_page_ids": [ 80506, 2112491, 2112491 ], "anchor_spans": [ [ 3, 6 ], [ 330, 341 ], [ 391, 402 ] ] }, { "plaintext": "The channel capture effect is a phenomenon where one user of a shared medium \"captures\" the medium for a significant time. During this period (usually 16 frames), other users are denied use of the medium. This effect was first seen in networks using CSMA/CD on Ethernet. Because of this effect, the most data-intense connection dominates the multiple-access wireless channel. This happens in Ethernet links because of the way nodes \"back off\" from the link and attempt to re-access it. In the Ethernet protocol, when a communication collision happens (when two users of the medium try to send at the same time), each user waits for a random period of time before re-accessing the link. However, a user will wait (\"back off\") for a random amount of time proportional to the number of times it has successively tried to access the link. The channel capture effect happens when one user continues to \"win\" the link.", "section_idx": 5, "section_name": "Channel capture effect", "target_page_ids": [ 13748865 ], "anchor_spans": [ [ 63, 76 ] ] }, { "plaintext": "For example, user A and user B both try to access a quiet link at the same time. Since they detect a collision, user A waits for a random time between 0 and 1 time units and so does user B. Let's say user A chooses a lower back-off time. User A then begins to use the link and B allows it to finish sending its frame. If user A still has more to send, then user A and user B will cause another data collision. A will once again choose a random back-off time between 0 and 1, but user B will choose a back-off time between 0 and 3 – because this is B's second time colliding in a row. Chances are A will \"win\" this one again. If this continues, A will most likely win all the collision battles, and after 16 collisions (the number of tries before a user backs down for an extended period of time), user A will have \"captured\" the channel.", "section_idx": 5, "section_name": "Channel capture effect", "target_page_ids": [ 41172 ], "anchor_spans": [ [ 311, 316 ] ] }, { "plaintext": "The ability of one node to capture the entire medium is decreased as the number of nodes increases. This is because as the number of nodes increases, there is a higher probability that one of the \"other\" nodes will have a lower back-off time than the capturing node.", "section_idx": 5, "section_name": "Channel capture effect", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The channel capture effect creates a situation where one station is able to transmit while others are continually backing off, thus leading to a situation of short-term unfairness. Yet, the situation is long-term fair because every station has the opportunity to \"capture\" the medium once one station is done transmitting. The efficiency of the channel is increased when one node has captured the channel.", "section_idx": 5, "section_name": "Channel capture effect", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "A negative side effect of the capture effect would be the idle time created due to stations backing off. Once one station is finished transmitting on the medium, large idle times are present because all other stations were continually backing off. In some instances, back-off can occur for so long that some stations actually discard packets because maximum attempt limits have been reached.", "section_idx": 5, "section_name": "Channel capture effect", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "CSMA/CD was used in now-obsolete shared media Ethernet variants (10BASE5, 10BASE2), and in the early versions of twisted-pair Ethernet, which used repeater hubs. Modern Ethernet networks, built with switches and full-duplex connections, no longer need to use CSMA/CD, because each Ethernet segment, or collision domain, is now isolated. CSMA/CD is still supported for backwards compatibility and for half-duplex connections. The IEEE 802.3 standard, which defines all Ethernet variants, for historical reasons still bore the title \"Carrier sense multiple access with collision detection (CSMA/CD) access method and physical layer specifications\" until 802.3-2008, which uses new name \"IEEE Standard for Ethernet\".", "section_idx": 6, "section_name": "Applications", "target_page_ids": [ 9499, 35201, 35200, 35203, 1937926, 40614, 2112491, 200823, 14791 ], "anchor_spans": [ [ 33, 54 ], [ 65, 72 ], [ 74, 81 ], [ 113, 134 ], [ 147, 159 ], [ 199, 207 ], [ 212, 223 ], [ 302, 318 ], [ 429, 439 ] ] }, { "plaintext": " Carrier-sense multiple access with collision avoidance (CSMA/CA)", "section_idx": 7, "section_name": "See also", "target_page_ids": [ 40846 ], "anchor_spans": [ [ 1, 55 ] ] }, { "plaintext": " IEEE 802.3", "section_idx": 9, "section_name": "References", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "载波侦听多路访问", "section_idx": 9, "section_name": "References", "target_page_ids": [], "anchor_spans": [] } ]

[ "Media_access_control", "Ethernet" ]

[]

[ { "plaintext": "In telecommunication, the term carrier shift has the following meanings: ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374 ], "anchor_spans": [ [ 3, 20 ] ] }, { "plaintext": "In the transmission of binary or teletypewriter signals, keying in which the frequency of the carrier signal is shifted in one direction for marking signals and in the opposite direction for spacing signals.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 609152, 219202, 31247, 12481202, 153217 ], "anchor_spans": [ [ 7, 19 ], [ 23, 29 ], [ 33, 47 ], [ 57, 63 ], [ 94, 108 ] ] }, { "plaintext": "In amplitude modulation, a condition that results from imperfect modulation in which the positive and negative excursions of the modulating envelope are unequal in amplitude.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 1140, 57260 ], "anchor_spans": [ [ 3, 23 ], [ 140, 148 ] ] }, { "plaintext": "Note 1: The carrier shift results in a change in carrier power. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Note 2: The carrier shift may be a shift to a higher or to a lower frequency. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] } ]

[ "Radio_modulation_modes" ]

[]

[ { "plaintext": "A carrier system is a telecommunications system that transmits information, such as the voice signals of a telephone call and the video signals of television, by modulation of one or multiple carrier signals above the principal voice frequency or data rate.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 40925, 609152, 406703, 29831, 153217 ], "anchor_spans": [ [ 22, 47 ], [ 53, 62 ], [ 107, 121 ], [ 147, 157 ], [ 192, 206 ] ] }, { "plaintext": "Carrier systems typically transmit multiple channels of communication simultaneously over the shared medium using various forms of multiplexing. Prominent multiplexing methods of the carrier signal are time-division multiplexing (TDM) and frequency-division multiplexing (FDM). A cable television system is an example of frequency-division multiplexing. Many television programs are carried simultaneously on the same coaxial cable by sending each at a different frequency. Multiple layers of multiplexing may ultimately be performed upon a given input signal. For example, in the public switched telephone network, many telephone calls are sent over shared trunk lines by time-division multiplexing. For long-distance calls several of these channels may be sent over a communications satellite link by frequency-division multiplexing. At a given receiving node, specific channels may be demultiplexed individually.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 13748865, 41389, 153217, 41796, 86376, 7587, 46380, 41703, 468436, 45207, 998116 ], "anchor_spans": [ [ 94, 107 ], [ 131, 143 ], [ 183, 197 ], [ 202, 228 ], [ 239, 270 ], [ 280, 303 ], [ 418, 431 ], [ 553, 559 ], [ 581, 614 ], [ 770, 794 ], [ 857, 861 ] ] }, { "plaintext": "The purpose of carrier systems is to save money by carrying more traffic on less infrastructure. 19th century telephone systems, operating at baseband, could only carry one telephone call on each wire, hence routes with heavy traffic needed many wires.", "section_idx": 1, "section_name": "History", "target_page_ids": [ 174521, 40773 ], "anchor_spans": [ [ 81, 95 ], [ 143, 151 ] ] }, { "plaintext": "In the 1920s, frequency-division multiplexing could carry several circuits on the same balanced wires, and by the 1930s L-carrier and similar systems carried hundreds of calls at a time on coaxial cables.", "section_idx": 1, "section_name": "History", "target_page_ids": [ 40767, 9494538, 46380 ], "anchor_spans": [ [ 87, 101 ], [ 120, 129 ], [ 189, 202 ] ] }, { "plaintext": "Capacity of these systems increased in the middle of the century, while in the 1950s researchers began to take seriously the possibility of saving money on the terminal equipment by using time-division multiplexing. This work led to T-carrier and similar digital systems for local use.", "section_idx": 1, "section_name": "History", "target_page_ids": [ 41796, 41779 ], "anchor_spans": [ [ 188, 214 ], [ 233, 242 ] ] }, { "plaintext": "Due to the shorter repeater spacings required by digital systems, long-distance still used FDM until the late 1970s when optical fiber was improved to the point that digital connections became the cheapest ones for all distances, short and long. By the end of the century, analog connections between and within telephone exchanges became rare.", "section_idx": 1, "section_name": "History", "target_page_ids": [ 41655, 86376, 3372377, 26668156 ], "anchor_spans": [ [ 19, 27 ], [ 91, 94 ], [ 121, 134 ], [ 311, 329 ] ] }, { "plaintext": " Channel access method", "section_idx": 2, "section_name": "See also", "target_page_ids": [ 86392 ], "anchor_spans": [ [ 1, 22 ] ] }, { "plaintext": " J-carrier", "section_idx": 4, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] } ]

[ "Multiplexing" ]

[]

[ { "plaintext": "In telecommunication, Carson's bandwidth rule defines the approximate bandwidth requirements of communications system components for a carrier signal that is frequency modulated by a continuous or broad spectrum of frequencies rather than a single frequency. Carson's rule does not apply well when the modulating signal contains discontinuities, such as a square wave. Carson's rule originates from John Renshaw Carson's 1922 paper.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 3967, 40925, 153217, 10835, 14174420 ], "anchor_spans": [ [ 3, 20 ], [ 70, 79 ], [ 96, 117 ], [ 135, 149 ], [ 158, 177 ], [ 399, 418 ] ] }, { "plaintext": "Carson's bandwidth rule is expressed by the relation:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "where:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " is the bandwidth requirement;", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " is the peak frequency deviation;", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 41187 ], "anchor_spans": [ [ 13, 32 ] ] }, { "plaintext": " is the highest frequency in the modulating signal.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "For example, a typical VHF/UHF two-way radio signal using FM mode, with 5 kHz peak deviation, and a maximum audio frequency of 3kHz, would require an approximate bandwidth of 2 * (5kHz + 3kHz) = 16kHz.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 14121 ], "anchor_spans": [ [ 74, 77 ] ] }, { "plaintext": "Standard broadcast stereo FM, with a peak deviation of 75kHz, has a highest modulating frequency (which combines L+R and L-R) of 53kHz. Most of the energy therefore falls within an approximate bandwidth of 2 * (75 + 53) = 256kHz. (Geographically close FM broadcast transmitters are almost always assigned nominal center frequencies at least 400kHz apart).", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 1607203 ], "anchor_spans": [ [ 19, 28 ] ] }, { "plaintext": "Carson's bandwidth rule is often applied to transmitters, antennas, optical sources, receivers, photodetectors, and other communications system components.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 61164, 187317, 491851, 1353789 ], "anchor_spans": [ [ 44, 55 ], [ 58, 65 ], [ 85, 93 ], [ 96, 109 ] ] }, { "plaintext": "Any frequency modulated signal will have an infinite number of sidebands and hence an infinite bandwidth but, in practice, all significant sideband energy (98% or more) is concentrated within the bandwidth defined by Carson's rule. It is a useful approximation, but setting the arbitrary definition of occupied bandwidth at 98% of the power still means that the power outside the band is about less than the carrier inside, therefore Carson's Rule is of little use in spectrum planning.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 4312667 ], "anchor_spans": [ [ 469, 486 ] ] }, { "plaintext": "Leon W. Couch II, \"Digital and Analog Communication Systems, 6th Edition\", Prentice-Hall, Inc., 2001. ", "section_idx": 1, "section_name": "References", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Carson-Formel", "section_idx": 1, "section_name": "References", "target_page_ids": [], "anchor_spans": [] } ]

[ "Telecommunication_theory", "Rules_of_thumb" ]

[]

[ { "plaintext": "In telecommunications and radar, a Cassegrain antenna is a parabolic antenna in which the feed antenna is mounted at or behind the surface of the concave main parabolic reflector dish and is aimed at a smaller convex secondary reflector suspended in front of the primary reflector. The beam of radio waves from the feed illuminates the secondary reflector, which reflects it back to the main reflector dish, which reflects it forward again to form the desired beam. The Cassegrain design is widely used in parabolic antennas, particularly in large antennas such as those in satellite ground stations, radio telescopes, and communication satellites.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 25676, 208264, 3866029, 192590, 5732433, 1042310, 46656, 45207 ], "anchor_spans": [ [ 3, 20 ], [ 26, 31 ], [ 59, 76 ], [ 90, 102 ], [ 159, 178 ], [ 210, 216 ], [ 577, 601 ], [ 604, 619 ], [ 626, 650 ] ] }, { "plaintext": "The primary reflector is a paraboloid, while the shape of the convex secondary reflector is a hyperboloid. The geometrical condition for radiating a collimated, plane wave beam is that the feed antenna is located at the far focus of the hyperboloid, while the focus of the primary reflector coincides with the near focus of the hyperboloid. Usually the secondary reflector and the feed antenna are located on the central axis of the dish. However, in offset Cassegrain configurations, the primary dish reflector is asymmetric, and its focus, and the secondary reflector, are located to one side of the dish, so that the secondary reflector does not partially obstruct the beam.", "section_idx": 1, "section_name": "Geometry", "target_page_ids": [ 145845, 145844, 53788, 1032607 ], "anchor_spans": [ [ 27, 37 ], [ 94, 105 ], [ 190, 202 ], [ 225, 230 ] ] }, { "plaintext": "This design is an alternative to the most common parabolic antenna design, called \"front feed\" or \"prime focus\", in which the feed antenna itself is mounted suspended in front of the dish at the focus, pointed back toward the dish. The Cassegrain is a more complex design, but in certain applications it has advantages over front feed that can justify its increased complexity:", "section_idx": 2, "section_name": "Advantages", "target_page_ids": [ 3866029 ], "anchor_spans": [ [ 126, 138 ] ] }, { "plaintext": " The feed antennas and associated waveguides and \"front end\" electronics can be located on or behind the dish, rather than suspended in front where they block part of the outgoing beam. Therefore, this design is used for antennas with bulky or complicated feeds, such as satellite communication ground antennas, radio telescopes, and the antennas on some communication satellites.", "section_idx": 2, "section_name": "Advantages", "target_page_ids": [ 2785376, 45207, 46656, 45207 ], "anchor_spans": [ [ 50, 59 ], [ 272, 295 ], [ 313, 328 ], [ 356, 379 ] ] }, { "plaintext": " Another advantage, important in satellite ground antennas and radio telescopes, is that because the feed antenna is directed forward, rather than backward toward the dish as in a front-fed antenna, the spillover sidelobes caused by portions of the beam that miss the secondary reflector are directed upwards toward the cold sky rather than downwards towards the warm earth. In receiving antennas this reduces reception of ground noise, resulting in a lower antenna noise temperature.", "section_idx": 2, "section_name": "Advantages", "target_page_ids": [ 46656, 1754982, 940296, 41420 ], "anchor_spans": [ [ 63, 78 ], [ 213, 221 ], [ 424, 436 ], [ 467, 484 ] ] }, { "plaintext": " Dual reflector shaping: The presence of a second reflecting surface in the signal path allows additional opportunities for tailoring the radiation pattern for maximum performance. For example, the gain of ordinary parabolic antennas is reduced because the radiation of the feed antenna falls off toward the outer parts of the dish, resulting in lower \"illumination\" of those parts. In \"dual reflector shaping\" the shape of the secondary reflector is altered to direct more signal power to outer areas of the dish, resulting in more uniform illumination of the primary, to maximize the gain. However, this results in a secondary that is no longer precisely hyperbolic (though it is still very close), so the constant phase property is lost. This phase error, however, can be compensated for by slightly tweaking the shape of the primary mirror. The result is a higher gain, or gain/spillover ratio, at the cost of surfaces that are trickier to fabricate and test. Other dish illumination patterns can also be synthesized, such as patterns with high taper at the dish edge for ultra-low spillover sidelobes, and patterns with a central \"hole\" to reduce feed shadowing.", "section_idx": 2, "section_name": "Advantages", "target_page_ids": [ 1754982 ], "anchor_spans": [ [ 1100, 1108 ] ] }, { "plaintext": " Another reason for using the Cassegrain design is to increase the focal length of the antenna, to reduce sidelobes, among other advantages. Parabolic reflectors used in dish antennas have a large curvature and short focal length; the focal point is located near the mouth of the dish, to reduce the length of the supports required to hold the feed structure or secondary reflector. The focal ratio (f-number, the ratio of the focal length to the dish diameter) of typical parabolic antennas is 0.25–0.8, compared to 3–8 for parabolic mirrors used in optical systems such as telescopes. In a front-fed antenna, a \"flatter\" parabolic dish with a long focal length would require an impractically elaborate support structure to hold the feed rigid with respect to the dish. However, the drawback of this small focal ratio is that the antenna is sensitive to small deviations from the focal point: the angular width that it can effectively focus is small. Modern parabolic antennas in radio telescopes and communications satellites often use arrays of feedhorns clustered around the focal point, to create a particular beam pattern. These require the good off-axis focusing characteristics of a large focal ratio, and because the convex secondary reflector of the Cassegrain antenna increases it significantly, these antennas typically use a Cassegrain design.", "section_idx": 2, "section_name": "Advantages", "target_page_ids": [ 82269, 82269, 1032610, 168244 ], "anchor_spans": [ [ 67, 79 ], [ 218, 230 ], [ 236, 247 ], [ 388, 399 ] ] }, { "plaintext": " The longer focal length also improves crosspolarization discrimination of off-axis feeds, important in satellite antennas that use the two orthogonal polarization modes to transmit separate channels of information.", "section_idx": 2, "section_name": "Advantages", "target_page_ids": [ 187317 ], "anchor_spans": [ [ 151, 163 ] ] }, { "plaintext": "A disadvantage of the Cassegrain is that the feed horn(s) must have a narrower beamwidth (higher gain) to focus its radiation on the smaller secondary reflector, instead of the wider primary reflector as in front-fed dishes. The angular width the secondary reflector subtends at the feed horn is typically 10–15°, as opposed to 120–180° the main reflector subtends in a front-fed dish. Therefore, the feed horn must be longer for a given wavelength.", "section_idx": 2, "section_name": "Advantages", "target_page_ids": [ 40780, 49693 ], "anchor_spans": [ [ 79, 88 ], [ 97, 101 ] ] }, { "plaintext": "A beam waveguide antenna is a type of complicated Cassegrain antenna with a long radio wave path to allow the feed electronics to be located at ground level. It is used in very large steerable radio telescopes and satellite ground antennas, where the feed electronics are too complicated and bulky, or requires too much maintenance and alterations, to locate on the dish; for example those using cryogenically-cooled amplifiers. The beam of incoming radio waves from the secondary reflector is reflected by additional mirrors in a long twisting path through the axes of the altazimuth mount, so the antenna can be steered without interrupting the beam, and then down through the antenna tower to a feed building at ground level.", "section_idx": 3, "section_name": "Beam waveguide antenna", "target_page_ids": [ 31250782, 1055255 ], "anchor_spans": [ [ 2, 24 ], [ 577, 593 ] ] }, { "plaintext": "The Cassegrain antenna design was adapted from the Cassegrain telescope, a type of reflecting telescope developed around 1672 and attributed to French Province England priest Laurent Cassegrain. The first Cassegrain antenna was invented and patented by Cochrane and Whitehead at Elliot Bros in Borehamwood, England, in 1952. The patent, British Patent Number 700868, was subsequently challenged in court, but prevailed.", "section_idx": 4, "section_name": "History", "target_page_ids": [ 2151693, 266861, 436513 ], "anchor_spans": [ [ 51, 71 ], [ 83, 103 ], [ 175, 193 ] ] }, { "plaintext": " Cassegrain reflector", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 2151693 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Nasmyth telescope", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 7024269 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Cassegrain subreflector design article", "section_idx": 7, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Parabolantenne", "section_idx": 7, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] } ]

[ "Radio_frequency_antenna_types", "Antennas_(radio)" ]

[]

[ { "plaintext": "In computer networking, cell relay refers to a method of statistically multiplexing small fixed-length packets, called \"cells\", to transport data between computers or kinds of network equipment. It is a reliable, connection-oriented packet switched data communications protocol.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 4122592, 1965793, 43734, 2563492, 2137712, 43339, 28030850 ], "anchor_spans": [ [ 3, 19 ], [ 57, 83 ], [ 103, 110 ], [ 204, 212 ], [ 214, 233 ], [ 234, 249 ], [ 255, 278 ] ] }, { "plaintext": "Cell relay transmission rates usually are between 56 kbit/s and several gigabits per second. ATM, a particularly popular form of cell relay, is most commonly used for home DSL connections, which often runs between 128 kbit/s and 1.544 Mbit/s (DS1), and for high-speed backbone connections (OC-3 and faster).", "section_idx": 1, "section_name": "Transmission Rates", "target_page_ids": [ 272290, 14832328, 14832328, 2499, 41038, 14832328, 907542, 1861262 ], "anchor_spans": [ [ 11, 29 ], [ 53, 59 ], [ 72, 91 ], [ 94, 97 ], [ 173, 176 ], [ 236, 242 ], [ 244, 247 ], [ 291, 295 ] ] }, { "plaintext": "Cell relay protocols have neither flow control nor error correction capability, are information-content independent, and correspond only to layers one and two of the OSI Reference Model.", "section_idx": 1, "section_name": "Transmission Rates", "target_page_ids": [ 1619428, 10375, 22747 ], "anchor_spans": [ [ 34, 46 ], [ 51, 67 ], [ 166, 185 ] ] }, { "plaintext": "Cell relay can be used for delay- and jitter-sensitive traffic such as voice and video.", "section_idx": 1, "section_name": "Transmission Rates", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Cell relay systems break variable-length user packets into groups of fixed-length cells, that add addressing and verification information. Frame length is fixed in networking hardware, based on time delay and user packet-length considerations. One user data message may be segmented over many cells.", "section_idx": 1, "section_name": "Transmission Rates", "target_page_ids": [ 41172, 1699254 ], "anchor_spans": [ [ 139, 144 ], [ 164, 183 ] ] }, { "plaintext": "Cell relay systems may also carry bitstream-based data such as PDH traffic, by breaking it into streams of cells, with a lightweight synchronization and clock recovery shim. Thus cell relay systems may potentially carry any combination of stream-based and packet-based data. This is a form of statistical time division multiplexing.", "section_idx": 1, "section_name": "Transmission Rates", "target_page_ids": [ 38512, 1965793 ], "anchor_spans": [ [ 63, 66 ], [ 293, 331 ] ] }, { "plaintext": "Cell relay is an implementation of fast packet-switching technology that is used in connection-oriented broadband integrated services digital networks (B-ISDN, and its better-known supporting technology ATM) and connectionless IEEE 802.6 switched multi-megabit data service (SMDS).", "section_idx": 1, "section_name": "Transmission Rates", "target_page_ids": [ 41142, 38514, 262259, 1272645 ], "anchor_spans": [ [ 35, 56 ], [ 152, 158 ], [ 227, 237 ], [ 275, 279 ] ] }, { "plaintext": "At any time there is information to be transmitted; the switch basically sends the data units. Connections don't have to be negotiated like circuit switching. Channels don't have to be allocated because channels do not exist in ATM, and on condition that there is an adequate amount of bandwidth to maintain it, there can be indefinite transmissions over the same facility.", "section_idx": 1, "section_name": "Transmission Rates", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Cell relay utilizes data cells of a persistent size. Frames are comparable to data packets; however they contrast from cells in that they may fluctuate in size based on circumstances. This type of technology is not secure for the reason that its procedures do not support error handling or data recovery. Per se, all delicate and significant transmissions may perhaps be transported faster via fixed-sized cells, which are simpler to transmit compared to variable-sized frames or packets.", "section_idx": 1, "section_name": "Transmission Rates", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Cell relay is extremely reliable for transporting vital data. Switching devices give the precise method to cells as each endpoint address embedded in a cell. An example of cell relay is ATM, a prevalent form utilized to transfer a cell with a fixed size of 53 bytes.", "section_idx": 1, "section_name": "Transmission Rates", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Minoli, Daniel, and Michael Vitella. ATM and Cell Relay Service for Corporate Environments. New York: McGraw-Hill, 1994. Print.", "section_idx": 2, "section_name": "References", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Minoli, Daniel, and George Dobrowski. Principles of Signaling for Cell Relay and Frame Relay. Boston: Artech House, 1995. Print.", "section_idx": 2, "section_name": "References", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Minoli, Daniel, and George Dobrowski. Principles of Signaling for Cell Relay and Frame Relay. Boston: Artech House, 1995. Print.", "section_idx": 2, "section_name": "References", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Any Transport over MPLS - Cisco Systems.\" Cisco Systems, Inc. Web. 29 Nov. 2011. <>.", "section_idx": 2, "section_name": "References", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Davidson, Robert P. Broadband Networking ABCs for Managers: ATM, BISDN, Cell/frame Relay to SONET. New York: John Wiley & Sons, 1994. Print.", "section_idx": 2, "section_name": "References", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Conti, Marco, Enrico Gregori, and Luciano Lenzini. Metropolitan Area Networks. London: Springer, 1997. Print.", "section_idx": 2, "section_name": "References", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Commutation de paquets", "section_idx": 2, "section_name": "References", "target_page_ids": [], "anchor_spans": [] } ]

[ "Multiplexing", "Network_protocols", "Packets_(information_technology)" ]

[]

[ { "plaintext": "The caesium standard is a primary frequency standard in which the photon absorption by transitions between the two hyperfine ground states of caesium-133 atoms is used to control the output frequency. The first caesium clock was built by Louis Essen in 1955 at the National Physical Laboratory in the UK. and promoted worldwide by Gernot M. R. Winkler of the United States Naval Observatory.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 41194, 1384005, 527046, 225982, 2526954, 902, 495065, 250381, 56764910, 43596 ], "anchor_spans": [ [ 34, 52 ], [ 66, 83 ], [ 115, 124 ], [ 125, 137 ], [ 142, 153 ], [ 154, 158 ], [ 238, 249 ], [ 265, 293 ], [ 331, 351 ], [ 359, 390 ] ] }, { "plaintext": "Caesium atomic clocks are one of the most accurate time and frequency standards, and serve as the primary standard for the definition of the second in the International System of Units (SI) (the modern form of the metric system). By definition, radiation produced by the transition between the two hyperfine ground states of caesium (in the absence of external influences such as the Earth's magnetic field) has a frequency, , of exactly . That value was chosen so that the caesium second equalled, to the limit of human measuring ability in 1960 when it was adopted, the existing standard ephemeris second based on the Earth's orbit around the Sun. Because no other measurement involving time had been as precise, the effect of the change was less than the experimental uncertainty of all existing measurements.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 25453985, 200069, 26873, 26764, 44142, 9994, 9228, 26751 ], "anchor_spans": [ [ 8, 20 ], [ 98, 114 ], [ 141, 147 ], [ 155, 184 ], [ 214, 227 ], [ 591, 607 ], [ 621, 626 ], [ 646, 649 ] ] }, { "plaintext": "While the second is the only base unit to be explicitly defined in terms of the caesium standard, the majority of SI units have definitions that mention either the second, or other units defined using the second. Consequently, every base unit except the mole and every named derived unit except the coulomb, ohm, siemens, weber, gray, sievert, radian, and steradian have values that are implicitly defined by the properties of the caesium-133 hyperfine transition radiation. And of these, all but the mole, the coulomb, and the dimensionless radian and steradian are implicitly defined by the general properties of electromagnetic radiation. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 26872, 26876, 51331 ], "anchor_spans": [ [ 29, 38 ], [ 269, 287 ], [ 528, 541 ] ] }, { "plaintext": "The official definition of the second was first given by the BIPM at the 13th General Conference on Weights and Measures in 1967 as: \"The second is the duration of periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom.\" At its 1997 meeting the BIPM added to the previous definition the following specification: \"This definition refers to a caesium atom at rest at a temperature of 0K.\"", "section_idx": 1, "section_name": "Technical details", "target_page_ids": [ 26873, 4739, 7339 ], "anchor_spans": [ [ 31, 37 ], [ 61, 65 ], [ 78, 120 ] ] }, { "plaintext": "The BIPM restated this definition in its 26th conference (2018), \"The second is defined by taking the fixed numerical value of the caesium frequency ∆Cs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9 192 631 770 when expressed in the unit Hz, which is equal to s–1.\"", "section_idx": 1, "section_name": "Technical details", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The meaning of the preceding definition is as follows. The caesium atom has a ground state electron state with configuration [Xe] 6s1 and, consequently, atomic term symbol 2S1/2. This means that there is one unpaired electron and the total electron spin of the atom is 1/2. Moreover, the nucleus of caesium-133 has a nuclear spin equal to 7/2. The simultaneous presence of electron spin and nuclear spin leads, by a mechanism called hyperfine interaction, to a (small) splitting of all energy levels into two sub-levels. One of the sub-levels corresponds to the electron and nuclear spin being parallel (i.e., pointing in the same direction), leading to a total spin F equal to ; the other sub-level corresponds to anti-parallel electron and nuclear spin (i.e., pointing in opposite directions), leading to a total spin . In the caesium atom it so happens that the sub-level lowest in energy is the one with , while the sub-level lies energetically slightly above. When the atom is irradiated with electromagnetic radiation having an energy corresponding to the energetic difference between the two sub-levels the radiation is absorbed and the atom is excited, going from the sub-level to the one. After a small fraction of a second the atom will re-emit the radiation and return to its ground state. From the definition of the second it follows that the radiation in question has a frequency of exactly , corresponding to a wavelength of about 3.26cm and therefore belonging to the microwave range.", "section_idx": 1, "section_name": "Technical details", "target_page_ids": [ 67211, 1482326, 527046, 10134, 20097 ], "anchor_spans": [ [ 111, 124 ], [ 153, 171 ], [ 433, 454 ], [ 1429, 1439 ], [ 1487, 1496 ] ] }, { "plaintext": "This particular cesium resonance was agreed upon under la Convention du Mètre and remains to the present time as the official definition of the second for the world community.", "section_idx": 1, "section_name": "Technical details", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Note that a common confusion involves the conversion from angular frequency () to frequency (), or vice-versa. Angular frequencies are conventionally given as s–1 in scientific literature, but here the units implicitly mean radians per second. In contrast, the unit Hz should be interpreted as cycles per second. The conversion formula is , which implies that 1 Hz corresponds to an angular frequency of approximately 6.28 radians per second (or 6.28 s–1 where radians is omitted for brevity by convention).", "section_idx": 1, "section_name": "Technical details", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Suppose the caesium standard has the parameters:", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Velocity: c", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 28736 ], "anchor_spans": [ [ 1, 9 ] ] }, { "plaintext": " Energy/frequency: h", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 19594213 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Time period: ", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Frequency: ", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Wavelength: ", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Photon energy: ", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Photon mass equivalent: ", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 422481 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": "The first set of units defined using the caesium standard were those relating to time, with the second being defined in 1967 as \"the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom\" meaning that:", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " 1 second, s, = 9,192,631,770 ", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 26873 ], "anchor_spans": [ [ 3, 9 ] ] }, { "plaintext": " 1 hertz, Hz, = 1/s = ", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 14121 ], "anchor_spans": [ [ 3, 8 ] ] }, { "plaintext": " 1 becquerel, Bq, = 1 nuclear decay/s = nuclear decays/", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 155835 ], "anchor_spans": [ [ 3, 12 ] ] }, { "plaintext": "This also linked the definitions of the derived units relating to force and energy (see below) and of the ampere, whose definition at the time made reference to the newton, to the caesium standard. Before 1967 the SI units of time and frequency were defined using the tropical year and before 1960 by the length of the mean solar day", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 25453345, 143047 ], "anchor_spans": [ [ 268, 281 ], [ 319, 333 ] ] }, { "plaintext": "In 1983, the meter was, indirectly, defined in terms of the caesium standard with the formal definition \"The metre is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second. This implied:", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " 1 metre, m, = = c = ", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 18947 ], "anchor_spans": [ [ 3, 8 ] ] }, { "plaintext": " 1 radian, rad, = 1 m/m = / = 1 (dimensionless unit of angle)", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 26003 ], "anchor_spans": [ [ 3, 9 ] ] }, { "plaintext": " 1 steradian, sr, = 1 m2/m2 = 2/2 = 1 (dimensionless unit of solid angle)", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 28299, 94102 ], "anchor_spans": [ [ 3, 12 ], [ 62, 73 ] ] }, { "plaintext": "Between 1960 and 1983, the metre had been defined by the wavelength of a different transition frequency associated with the krypton 86 atom. This had a much higher frequency and shorter wavelength than the caesium standard, falling inside the visible spectrum. And between 1889 and 1960 by the international prototype meter.", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 2527017, 41464, 28200487 ], "anchor_spans": [ [ 124, 139 ], [ 243, 259 ], [ 294, 323 ] ] }, { "plaintext": "Following the 2019 redefinition of the SI base units, electromagnetic radiation, in general, was explicitly defined to have the exact parameters:", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 30291341 ], "anchor_spans": [ [ 14, 52 ] ] }, { "plaintext": " c = 299,792,458 m/s", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " h = J s", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "And the caesium 133 hyperfine transition radiation was explicitly defined to have frequency:", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " = 9,192,631,770 Hz", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Though the above values for c and were already obviously implicit in the definitions of the metre and second. Together they imply:", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " = = ", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " = c = m", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " = h = 9,192,631,770 Hz × J s = J", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " = = = kg", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Notably, the wavelength has a fairly human-sized value of about 3.26 centimetres and the photon energy is surprisingly close to the average molecular kinetic energy per degree of freedom per kelvin. From these it follows that:", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 17327, 26998547, 19593121 ], "anchor_spans": [ [ 150, 164 ], [ 169, 186 ], [ 191, 197 ] ] }, { "plaintext": " 1 kilogram, kg, = ", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 16619 ], "anchor_spans": [ [ 3, 11 ] ] }, { "plaintext": " 1 joule, J, = ", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 16327 ], "anchor_spans": [ [ 3, 8 ] ] }, { "plaintext": " 1 watt, W, = 1 J/s = ", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 21347693 ], "anchor_spans": [ [ 3, 7 ] ] }, { "plaintext": " 1 newton, N, = 1 J/m = /", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 72540 ], "anchor_spans": [ [ 3, 9 ] ] }, { "plaintext": " 1 pascal, Pa, = 1 N/m2 = /3", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 66014 ], "anchor_spans": [ [ 3, 9 ] ] }, { "plaintext": " 1 gray, Gy, = 1 J/kg = / = ", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 287152 ], "anchor_spans": [ [ 3, 7 ] ] }, { "plaintext": " 1 sievert, Sv, = the ionizing radiation dose equivalent to 1 gray of gamma rays", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 155823, 202522, 506276, 18616290 ], "anchor_spans": [ [ 3, 10 ], [ 22, 40 ], [ 46, 56 ], [ 70, 80 ] ] }, { "plaintext": "Prior to the revision, between 1889 and 2019, the family of metric (and later SI) units relating to mass, force, and energy were somewhat notoriously defined by the mass of the International Prototype of the Kilogram (IPK), a specific object stored at the headquarters of the International Bureau of Weights and Measures in Paris, meaning that any change to the mass of that object would have resulted in a change to the size of the kilogram and of the many other units whose value at the time depended on that of the kilogram.", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 23837739, 4739, 22989 ], "anchor_spans": [ [ 177, 216 ], [ 276, 320 ], [ 324, 329 ] ] }, { "plaintext": "From 1954 to 2019, the SI temperature scales were defined using the triple point of water and absolute zero. The 2019 revision replaced these with an assigned value for the Boltzmann constant, k, of J/K, implying:", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 30462, 1418, 53702 ], "anchor_spans": [ [ 68, 80 ], [ 94, 107 ], [ 173, 191 ] ] }, { "plaintext": " 1 kelvin, K, = J/2 per degree of freedom = per degree of freedom = per degree of freedom", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 19593121 ], "anchor_spans": [ [ 3, 9 ] ] }, { "plaintext": " Temperature in degrees Celsius, °C, = temperature in kelvins - 273.15 = ", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 19593040 ], "anchor_spans": [ [ 24, 31 ] ] }, { "plaintext": "The mole is an extremely large number of \"elementary entities\" (i.e. atoms, molecules, ions, etc). From 1969 to 2019, this number was 0.012 × the mass ratio between the IPK and a carbon 12 atom. The 2019 revision simplified this by assigning the Avogadro constant the exact value elementary entities per mole, thus, uniquely among the base units, the mole maintained its independence from the caesium standard:", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 41545, 902, 19555, 18963787, 2527115 ], "anchor_spans": [ [ 12, 37 ], [ 69, 74 ], [ 76, 85 ], [ 87, 91 ], [ 179, 193 ] ] }, { "plaintext": " 1 mole, mol, = elementary entities", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 37400 ], "anchor_spans": [ [ 3, 7 ] ] }, { "plaintext": " 1 katal, kat, = 1 mol/s = elementary entities/", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 17140 ], "anchor_spans": [ [ 3, 8 ] ] }, { "plaintext": "Prior to the revision, the ampere was defined as the current needed to produce a force between 2 parallel wires 1 m apart of 0.2 μN per meter. The 2019 revision replaced this definition by giving the charge on the electron, e, the exact value coulombs. Somewhat incongruously, the coulomb is still considered a derived unit and the amp a base unit, rather than vice versa. In any case, this convention entailed the following exact relationships between the SI electromagnetic units, electron, and the caesium-133 hyperfine transition radiation:", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 15868921, 72540, 174945 ], "anchor_spans": [ [ 71, 86 ], [ 129, 131 ], [ 196, 222 ] ] }, { "plaintext": " 1 coulomb, C, = e", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 47719 ], "anchor_spans": [ [ 3, 10 ] ] }, { "plaintext": " 1 ampere, or amp, A, = 1 C/s = e ", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 772 ], "anchor_spans": [ [ 3, 9 ] ] }, { "plaintext": " 1 volt, V, = 1 J/C = /e", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 32567 ], "anchor_spans": [ [ 3, 7 ] ] }, { "plaintext": " 1 farad, F, = 1 C/V = e2/", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 82355 ], "anchor_spans": [ [ 3, 8 ] ] }, { "plaintext": " 1 ohm, Ω, = 1 V/A = / e2 = h/e2", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 4462484 ], "anchor_spans": [ [ 3, 6 ] ] }, { "plaintext": " 1 siemens, S, = 1/Ω = e2/h", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 31109470 ], "anchor_spans": [ [ 3, 10 ] ] }, { "plaintext": " 1 weber, Wb, = 1 V s = /e = h/e", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 714710 ], "anchor_spans": [ [ 3, 8 ] ] }, { "plaintext": " 1 tesla, T, = 1 Wb/m2 = /e 2 = E/e c ", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 935979 ], "anchor_spans": [ [ 3, 8 ] ] }, { "plaintext": " 1 henry, H, = Ω s = h /e2", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 82354 ], "anchor_spans": [ [ 3, 8 ] ] }, { "plaintext": "From 1967 to 1979 the SI optical units, lumen, lux, and candela are defined using the Incandescent glow of platinum at its melting point. After 1979, the candela was defined as the luminous intensity of a monochromatic visible light source of frequency 540 Thz (i.e that of the caesium standard) and radiant intensity watts per steradian. This linked the definition of the candela to the caesium standard and, until 2019, to the IPK. Unlike the units relating to mass, energy, temperature, amount of substance, and electromagnetism, the optical units were not massively redefined in 2019, though they were indirectly affected since their values depend on that of the watt, and hence of the kilogram. The frequency used to define the optical units has the parameters:", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 213835, 23324, 313418, 69340305, 17939, 1215732, 19048, 9649, 20647050, 759264, 9532 ], "anchor_spans": [ [ 86, 98 ], [ 107, 115 ], [ 181, 199 ], [ 205, 218 ], [ 219, 232 ], [ 301, 318 ], [ 465, 469 ], [ 471, 477 ], [ 479, 490 ], [ 492, 511 ], [ 517, 533 ] ] }, { "plaintext": " Frequency: 540 THz", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Time period: fs", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 77689 ], "anchor_spans": [ [ 15, 17 ] ] }, { "plaintext": " Wavelength: μm", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 20627 ], "anchor_spans": [ [ 14, 16 ] ] }, { "plaintext": " Photon energy: Hz × J s = J", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " luminous efficacy, KCD, = 683 lm/W", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 1843931 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Luminous energy per photon, , = J × 683 lm/W = lm s", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 2545824 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": "This implies:", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " 1 lumen, lm, = ", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 1163049 ], "anchor_spans": [ [ 3, 8 ] ] }, { "plaintext": " 1 candela, cd, = 1 lm/sr = /sr", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 5385 ], "anchor_spans": [ [ 3, 10 ] ] }, { "plaintext": " 1 Lux, lx, = 1 lm/m2 = /2", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [ 155869 ], "anchor_spans": [ [ 3, 6 ] ] }, { "plaintext": "The parameters of the caesium 133 hyperfine transition radiation expressed exactly in SI units are:", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Frequency = 9,192,631,770 Hz", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Time period = ", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Wavelength = m", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Photon energy = J", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Photon mass equivalent = kg", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "If the 7 base units of the SI are expressed explicitly in terms of the SI defining constants, they are:", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " 1 second = ", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " 1 metre = c/", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " 1 kilogram = h /c2", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " 1 ampere = e ", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " 1 kelvin = h /k", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " 1 mole = elementary entities", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " 1 candela = h 2 KCD/sr", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "With 6 of the 7 base units notably having values that depend on that of . And appearing far more often than any of the other defining constants.", "section_idx": 2, "section_name": "Parameters and significance in the second and other SI units", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Atomic clock", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 25453985 ], "anchor_spans": [ [ 0, 12 ] ] }, { "plaintext": "Rubidium standard", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 41674 ], "anchor_spans": [ [ 0, 17 ] ] } ]

[ "Electronics_standards", "Atomic_clocks", "Caesium" ]

[]

[ { "plaintext": "Channel, channels, channeling, etc., may refer to:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Channel (geography), in physical geography, a landform consisting of the outline (banks) of the path of a narrow body of water.", "section_idx": 1, "section_name": "Geography", "target_page_ids": [ 851853 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " Channel Country, region of outback Australia in Queensland and partly in South Australia, Northern Territory and New South Wales.", "section_idx": 1, "section_name": "Geography", "target_page_ids": [ 1058846 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Channel Highway, a regional highway in Tasmania, Australia.", "section_idx": 1, "section_name": "Geography", "target_page_ids": [ 10385253 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Channel Islands, an archipelago in the English Channel, off the French coast of Normandy", "section_idx": 1, "section_name": "Geography", "target_page_ids": [ 5643 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Channel Tunnel or Chunnel, a rail tunnel underneath the English Channel", "section_idx": 1, "section_name": "Geography", "target_page_ids": [ 5702 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " English Channel, called simply \"The Channel\", the part of the Atlantic Ocean that separates Great Britain from northern France", "section_idx": 1, "section_name": "Geography", "target_page_ids": [ 9230 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Channel Islands of California, a chain of eight islands located in the Pacific Ocean off the coast of Southern California", "section_idx": 1, "section_name": "Geography", "target_page_ids": [ 330454 ], "anchor_spans": [ [ 1, 30 ] ] }, { "plaintext": " Channel Lake, Illinois, a census-designated place in Lake County, Illinois, United States", "section_idx": 1, "section_name": "Geography", "target_page_ids": [ 111450 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": " Channels State Forest, a state forest in Virginia, United States", "section_idx": 1, "section_name": "Geography", "target_page_ids": [ 17674901 ], "anchor_spans": [ [ 1, 22 ] ] }, { "plaintext": " Channel Glacier, a glacier in the Palmer Archipelago, Antarctica", "section_idx": 1, "section_name": "Geography", "target_page_ids": [ 29399277 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Channel Rock (disambiguation), various rocks", "section_idx": 1, "section_name": "Geography", "target_page_ids": [ 2550839 ], "anchor_spans": [ [ 1, 30 ] ] }, { "plaintext": " Channel Television, a division of British ITV", "section_idx": 2, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 180521 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": " Channels TV (Niger) A company of Tele Sahel.", "section_idx": 2, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 23124806 ], "anchor_spans": [ [ 34, 44 ] ] }, { "plaintext": " Channeler (The Wheel of Time), fictional characters in the Wheel of Time fantasy book series by Robert Jordan", "section_idx": 2, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 42571 ], "anchor_spans": [ [ 1, 30 ] ] }, { "plaintext": " Channeling (Rolemaster), a magic element in the Rolemaster role-playing game", "section_idx": 2, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 54056 ], "anchor_spans": [ [ 1, 24 ] ] }, { "plaintext": " Channels (band), fronted by former Jawbox singer/guitarist J. Robbins", "section_idx": 2, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 6765922 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Channels (film), a 2008 film", "section_idx": 2, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 26331548 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Pre-chorus, or build or channel, part of a song structure of popular music", "section_idx": 2, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 1189660 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " Communication channel, a transmission medium used to convey information", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 156700 ], "anchor_spans": [ [ 1, 22 ] ] }, { "plaintext": " Audio channel, a communications channel in a storage device used in operations such as multitrack recording and playback", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 12812363 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " Channel (broadcasting), a range of frequencies assigned for the operation of a television, radio, or other broadcast station", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 4051799 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": " Television channel, a television station or its cable/satellite counterpart", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 29840 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": " Channel (digital image), the grayscale representation of a primary color in a digital image", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 1883362 ], "anchor_spans": [ [ 1, 24 ] ] }, { "plaintext": " Channel (programming), in computer science, a tool used for interprocess communication", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 14524675 ], "anchor_spans": [ [ 1, 22 ] ] }, { "plaintext": " Channel I/O, in computing, a high-performance input/output (I/O) architecture", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 2470370 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Video blog, hosted by a video-sharing website or channel", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 1305348 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " Channel (semiconductor), a part of the structure of a field-effect transistor", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 41228216 ], "anchor_spans": [ [ 1, 24 ] ] }, { "plaintext": " Ion channel, a protein that allows ion flow through a cell membrane", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 15303 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Scattering channel, a concept in quantum mechanics", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 2172915 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": " Strut channel, a standardized formed structural system used in the construction and electrical industries", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 23884660 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " Structural channel", "section_idx": 3, "section_name": "Science and technology", "target_page_ids": [ 41165083 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": " The Channel (nightclub), a music venue in Boston, Massachusetts, U.S.", "section_idx": 4, "section_name": "Brands and enterprises", "target_page_ids": [ 7186210 ], "anchor_spans": [ [ 1, 24 ] ] }, { "plaintext": " Channel Express, a defunct British airline", "section_idx": 4, "section_name": "Brands and enterprises", "target_page_ids": [ 1990612 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Channel Home Centers, a defunct home improvement chain based in the northeastern United States", "section_idx": 4, "section_name": "Brands and enterprises", "target_page_ids": [ 8882553 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Channel (chart pattern), a pair of parallel trend lines that form a chart pattern for a stock or commodity", "section_idx": 5, "section_name": "Business and legal terms", "target_page_ids": [ 18943016 ], "anchor_spans": [ [ 1, 24 ] ] }, { "plaintext": " Distribution channel, a chain of intermediaries, each passing the product down the chain to the next organization, before it finally reaches the consumer", "section_idx": 5, "section_name": "Business and legal terms", "target_page_ids": [ 239863 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Legal channeling, the act of legally making one entity responsible for an event, and thereby dismissing other parties from liability", "section_idx": 5, "section_name": "Business and legal terms", "target_page_ids": [ 15669405 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Marketing channel, set of activities necessary to transfer the ownership of goods from the point of production to the point of consumption", "section_idx": 5, "section_name": "Business and legal terms", "target_page_ids": [ 12161148 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Channel (association football), football (soccer) terminology for particular areas of the pitch", "section_idx": 6, "section_name": "Sports", "target_page_ids": [ 14087920 ], "anchor_spans": [ [ 1, 31 ] ] }, { "plaintext": " Channel (horse), a racehorse", "section_idx": 6, "section_name": "Sports", "target_page_ids": [ 63581966 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Channel Football Club, an Australian football club in Tasmania", "section_idx": 6, "section_name": "Sports", "target_page_ids": [ 8767784 ], "anchor_spans": [ [ 1, 22 ] ] }, { "plaintext": " Channel catfish, a catfish species in North America", "section_idx": 7, "section_name": "Other uses", "target_page_ids": [ 1797053 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Meridian (Chinese medicine), or channels, a concept central to traditional Chinese medical techniques such as acupuncture, and to martial arts such as tai chi and qigong", "section_idx": 7, "section_name": "Other uses", "target_page_ids": [ 1208353 ], "anchor_spans": [ [ 1, 28 ] ] }, { "plaintext": " Mediumship or channelling, communication with spirits", "section_idx": 7, "section_name": "Other uses", "target_page_ids": [ 2269697 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " Canal (disambiguation)", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 2671423 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": " Chanel (disambiguation)", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 22712547 ], "anchor_spans": [ [ 1, 24 ] ] }, { "plaintext": " Channeling (disambiguation)", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 1958539 ], "anchor_spans": [ [ 1, 28 ] ] } ]

[]

[]

[ { "plaintext": "In telecommunications, the term channel noise level has the following meanings:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374 ], "anchor_spans": [ [ 3, 20 ] ] }, { "plaintext": "The ratio of the noise in the communication channel at any point in a transmission system to an arbitrary level chosen as a reference.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 3966982, 156700, 46982 ], "anchor_spans": [ [ 17, 22 ], [ 30, 51 ], [ 70, 89 ] ] }, { "plaintext": "The noise power spectral density in the frequency range of interest.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 202672 ], "anchor_spans": [ [ 10, 32 ] ] }, { "plaintext": "The average noise power in the frequency range of interest.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Ambient noise level", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 40712 ], "anchor_spans": [ [ 1, 20 ] ] } ]

[ "Noise_(electronics)" ]

[]

[ { "plaintext": "In telecommunication, channel reliability (ChR) is the percentage of time a communication channel was available for use in a specified period of scheduled availability. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 30012, 156700, 40760 ], "anchor_spans": [ [ 3, 20 ], [ 69, 73 ], [ 76, 97 ], [ 155, 167 ] ] }, { "plaintext": "Channel reliability is given by ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 1724836 ], "anchor_spans": [ [ 8, 19 ] ] }, { "plaintext": "where T o is the channel total outage time, T s is the channel total scheduled time, and T a is the channel total available time.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Federal Standard 1037C website", "section_idx": 2, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] } ]

[ "Telecommunication_theory" ]

[]

[ { "plaintext": "In telecommunications, a channel service unit (CSU) is a line bridging device for use with T-carrier, which", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 946963, 2702169, 41779 ], "anchor_spans": [ [ 3, 20 ], [ 57, 61 ], [ 62, 70 ], [ 91, 100 ] ] }, { "plaintext": "is used to perform loopback testing;", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 160478 ], "anchor_spans": [ [ 19, 27 ] ] }, { "plaintext": "may perform bit stuffing;", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 40802 ], "anchor_spans": [ [ 12, 24 ] ] }, { "plaintext": "may also provide a framing and formatting pattern compatible with the network;", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 41176, 46545 ], "anchor_spans": [ [ 19, 26 ], [ 70, 77 ] ] }, { "plaintext": "provides a barrier for electrical interference from either side of the unit; and", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "is the last signal regeneration point, on the loop side, coming from the central office, before the regenerated signal reaches a multiplexer or data terminal equipment (DTE).", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 26668156, 38542, 74041 ], "anchor_spans": [ [ 73, 87 ], [ 129, 140 ], [ 144, 167 ] ] }, { "plaintext": "CSUs can be categorized by the class of service they support (DS1, DS3, DDS, etc.) and by the capabilities within that class. For example, basic DS1 (T1) CSUs support loopback of each interface and will produce alarm indication signal to the provider's network interface device (NID) in the event of loss of signal from the customer-premises equipment (CPE). More advanced units will include internal monitors of the performance of the carrier in both directions and may have test pattern generation and monitor capabilities.", "section_idx": 1, "section_name": "Common varieties", "target_page_ids": [ 907542, 1219567, 2994865, 41409, 40982 ], "anchor_spans": [ [ 62, 65 ], [ 67, 70 ], [ 211, 234 ], [ 253, 277 ], [ 324, 351 ] ] }, { "plaintext": "CSUs are required by PSTN providers at digital interfaces that terminate in a DSU on the customer side. They are not used when the service terminates in a modem, such as the DSL family of service. The maintenance capabilities of the CSU provide important guidance as to whether the provider needs to dispatch a repairman to the customer location.", "section_idx": 2, "section_name": "Common practice", "target_page_ids": [ 468436, 40997, 41038 ], "anchor_spans": [ [ 21, 25 ], [ 78, 81 ], [ 174, 177 ] ] }, { "plaintext": " CSU/DSU", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 923209 ], "anchor_spans": [ [ 1, 8 ] ] } ]

[ "Telecommunications_equipment" ]

[]

[ { "plaintext": "Character interval: In a communications system, the total number of unit intervals required to transmit any given character, including synchronizing, information, error checking, or control characters, but not including signals that are not associated with individual characters. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 40925, 73443, 28738, 18985062, 10375, 5298 ], "anchor_spans": [ [ 25, 46 ], [ 114, 123 ], [ 135, 148 ], [ 150, 161 ], [ 163, 177 ], [ 182, 199 ] ] }, { "plaintext": "An example of a time interval that is excluded when determining character interval is any time added between the end of a stop signal and the beginning of the next start signal to accommodate changing transmission conditions, such as a change in data signaling rate or buffering requirements. This added time is defined as a part of the intercharacter interval.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 30012, 41750, 41744, 609152, 40998, 2406183, 41273 ], "anchor_spans": [ [ 16, 20 ], [ 122, 133 ], [ 164, 176 ], [ 201, 213 ], [ 246, 265 ], [ 269, 278 ], [ 337, 360 ] ] } ]

[ "Data_transmission" ]

[]

[ { "plaintext": "The characteristic impedance or surge impedance (usually written Z0) of a uniform transmission line is the ratio of the amplitudes of voltage and current of a single wave propagating along the line; that is, a wave travelling in one direction in the absence of reflections in the other direction. Alternatively, and equivalently, it can be defined as the input impedance of a transmission line when its length is infinite. Characteristic impedance is determined by the geometry and materials of the transmission line and, for a uniform line, is not dependent on its length. The SI unit of characteristic impedance is the ohm.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 41811, 32549, 6207, 23947184, 643036, 26764, 4462484 ], "anchor_spans": [ [ 82, 99 ], [ 134, 141 ], [ 146, 153 ], [ 261, 272 ], [ 355, 370 ], [ 578, 580 ], [ 621, 624 ] ] }, { "plaintext": "The characteristic impedance of a lossless transmission line is purely real, with no reactive component. Energy supplied by a source at one end of such a line is transmitted through the line without being dissipated in the line itself. A transmission line of finite length (lossless or lossy) that is terminated at one end with an impedance equal to the characteristic impedance appears to the source like an infinitely long transmission line and produces no reflections.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 20646438, 140710, 164572, 41957 ], "anchor_spans": [ [ 71, 75 ], [ 85, 93 ], [ 205, 215 ], [ 331, 340 ] ] }, { "plaintext": "The characteristic impedance of an infinite transmission line at a given angular frequency is the ratio of the voltage and current of a pure sinusoidal wave of the same frequency travelling along the line. This relation is also the case for finite transmission lines until the wave reaches the end of the line. Generally, a wave is reflected back along the line in the opposite direction. When the reflected wave reaches the source, it is reflected yet again, adding to the transmitted wave and changing the ratio of the voltage and current at the input so the causing the voltage-current ratio to no longer equal the characteristic impedance. This new ratio including the reflected energy is called the input impedance.", "section_idx": 1, "section_name": "Transmission line model", "target_page_ids": [ 643036 ], "anchor_spans": [ [ 707, 722 ] ] }, { "plaintext": "The input impedance of an infinite line is equal to the characteristic impedance since the transmitted wave is never reflected back from the end. Equivalently: The characteristic impedance of a line is that impedance which, when terminating an arbitrary length of line at its output, produces an input impedance of equal value. This is so because there is no reflection on a line terminated in its own characteristic impedance.", "section_idx": 1, "section_name": "Transmission line model", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Applying the transmission line model based on the telegrapher's equations as derived below, the general expression for the characteristic impedance of a transmission line is:", "section_idx": 1, "section_name": "Transmission line model", "target_page_ids": [ 5161169 ], "anchor_spans": [ [ 50, 73 ] ] }, { "plaintext": "where", "section_idx": 1, "section_name": "Transmission line model", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " is the resistance per unit length, considering the two conductors to be in series,", "section_idx": 1, "section_name": "Transmission line model", "target_page_ids": [ 61577, 270770 ], "anchor_spans": [ [ 8, 18 ], [ 73, 82 ] ] }, { "plaintext": " is the inductance per unit length,", "section_idx": 1, "section_name": "Transmission line model", "target_page_ids": [ 165146 ], "anchor_spans": [ [ 8, 18 ] ] }, { "plaintext": " is the conductance of the dielectric per unit length,", "section_idx": 1, "section_name": "Transmission line model", "target_page_ids": [ 61577 ], "anchor_spans": [ [ 8, 19 ] ] }, { "plaintext": " is the capacitance per unit length,", "section_idx": 1, "section_name": "Transmission line model", "target_page_ids": [ 140711 ], "anchor_spans": [ [ 8, 19 ] ] }, { "plaintext": " is the imaginary unit, and", "section_idx": 1, "section_name": "Transmission line model", "target_page_ids": [ 52358 ], "anchor_spans": [ [ 8, 22 ] ] }, { "plaintext": " is the angular frequency.", "section_idx": 1, "section_name": "Transmission line model", "target_page_ids": [ 199829 ], "anchor_spans": [ [ 8, 25 ] ] }, { "plaintext": "This expression extends to DC by letting tend to 0.", "section_idx": 1, "section_name": "Transmission line model", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "A surge of energy on a finite transmission line will see an impedance of prior to any reflections returning; hence surge impedance is an alternative name for characteristic impedance.", "section_idx": 1, "section_name": "Transmission line model", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Although an infinite line is assumed, since all quantities are per unit length, the “per length” parts of all the units cancel, and the characteristic impedance is independent of the length of the transmission line.", "section_idx": 1, "section_name": "Transmission line model", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The voltage and current phasors on the line are related by the characteristic impedance as:", "section_idx": 1, "section_name": "Transmission line model", "target_page_ids": [ 1256073 ], "anchor_spans": [ [ 24, 30 ] ] }, { "plaintext": "where the subscripts (+) and () mark the separate constants for the waves traveling forward (+) and backward ().", "section_idx": 1, "section_name": "Transmission line model", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The differential equations describing the dependence of the voltage and current on time and space are linear, so that a linear combination of solutions is again a solution. This means that we can consider solutions with a time dependence – doing so is functionally equivalent of solving for the Fourier coefficients for voltage and current amplitudes at some fixed angular frequency . Doing so causes the time dependence to factor out, leaving an ordinary differential equation for the coefficients, which will be phasors, dependent on position (space) only. Moreover, the parameters can be generalized to be frequency-dependent.", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [ 32549, 6207, 59038, 1256073 ], "anchor_spans": [ [ 60, 67 ], [ 72, 79 ], [ 296, 316 ], [ 515, 521 ] ] }, { "plaintext": "Let", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "and", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Take the positive direction for and in the loop to be clockwise.", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "We find that", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "and", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "or", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " and ", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "where", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " and .", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "These two first-order equations are easily uncoupled by a second differentiation, with the results:", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [ 32742753 ], "anchor_spans": [ [ 10, 31 ] ] }, { "plaintext": "and", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Notice that both and satisfy the same equation.", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Since is independent of and , it can be represented by a single constant That is:", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "so", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The minus sign is included for later convenience. Because of it, we can write the above equation as", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "which is correct for all transmission lines. And for typical transmission lines, that are built to make wire resistance loss small and insulation leakage conductance low, and further, with high frequencies, the inductive reactance and the capacitive admittance will both be large, so the constant is very close to being a real number:", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Further, with this definition of the position- or -dependent part will appear as in the exponential solutions of the equation, similar to the time-dependent part so the solution reads", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "where and are the constants of integration for the forward moving (+) and backward moving () waves, as in the prior section. When we recombine the time-dependent part we obtain the full solution:", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [ 147939 ], "anchor_spans": [ [ 20, 44 ] ] }, { "plaintext": "Since the equation for is the same form, it has a solution of the same form:", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "where and are again constants of integration.", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [ 147939 ], "anchor_spans": [ [ 22, 46 ] ] }, { "plaintext": "The above equations are the wave solution for and . In order to be compatible, they must still satisfy the original differential equations, one of which is", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Substituting the solutions for and into the above equation, we get", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "or", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Isolating distinct powers of and combining identical powers, we see that in order for the above equation to hold for all possible values of we must have:", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "For the co-efficients of ", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "For the co-efficients of ", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Since ", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "hence, for valid solutions require", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "It can be seen that the constant , defined in the above equations has the dimensions of impedance (ratio of voltage to current) and is a function of primary constants of the line and operating frequency. It is called the “characteristic impedance” of the transmission line, and conventionally denoted by .", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "which holds generally, for any transmission line. For well-functioning transmission lines, with either and both very small, or with very high, or all of the above, we get", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "hence the characteristic impedance is typically very close to being a real number. Manufacturers make commercial cables to approximate this condition very closely over a wide range of frequencies.", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "We follow an approach posted by Tim Healy. The line is modeled by a series of differential segments with differential series and shunt elements (as shown in the figure above). The characteristic impedance is defined as the ratio of the input voltage to the input current of a semi-infinite length of line. We call this impedance . That is, the impedance looking into the line on the left is . But, of course, if we go down the line one differential length , the impedance into the line is still . Hence we can say that the impedance looking into the line on the far left is equal to in parallel with and , all of which is in series with and . Hence:", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The terms cancel, leaving", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The first-power terms are the highest remaining order. In comparison to , the term with the factor may be discarded, since it is infinitesimal in comparison, leading to:", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "and hence", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Reversing the sign on the square root has the effect of changing the direction of the flow of current.", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The analysis of lossless lines provides an accurate approximation for real transmission lines that simplifies the mathematics considered in modeling transmission lines. A lossless line is defined as a transmission line that has no line resistance and no dielectric loss. This would imply that the conductors act like perfect conductors and the dielectric acts like a perfect dielectric. For a lossless line, R and G are both zero, so the equation for characteristic impedance derived above reduces to:", "section_idx": 3, "section_name": "Lossless line", "target_page_ids": [ 7090506 ], "anchor_spans": [ [ 254, 269 ] ] }, { "plaintext": "In particular, does not depend any more upon the frequency.", "section_idx": 3, "section_name": "Lossless line", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The above expression is wholly real, since the imaginary term has canceled out, implying that is purely resistive. For a lossless line terminated in , there is no loss of current across the line, and so the voltage remains the same along the line. The lossless line model is a useful approximation for many practical cases, such as low-loss transmission lines and transmission lines with high frequency. For both of these cases, and are much smaller than and , respectively, and can thus be ignored.", "section_idx": 3, "section_name": "Lossless line", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The solutions to the long line transmission equations include incident and reflected portions of the voltage and current:", "section_idx": 3, "section_name": "Lossless line", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "When the line is terminated with its characteristic impedance, the reflected portions of these equations are reduced to 0 and the solutions to the voltage and current along the transmission line are wholly incident. Without a reflection of the wave, the load that is being supplied by the line effectively blends into the line making it appear to be an infinite line. In a lossless line this implies that the voltage and current remain the same everywhere along the transmission line. Their magnitudes remain constant along the length of the line and are only rotated by a phase angle.", "section_idx": 3, "section_name": "Lossless line", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "In electric power transmission, the characteristic impedance of a transmission line is expressed in terms of the surge impedance loading (SIL), or natural loading, being the power loading at which reactive power is neither produced nor absorbed:", "section_idx": 4, "section_name": "Surge impedance loading", "target_page_ids": [ 38824, 1780823 ], "anchor_spans": [ [ 3, 30 ], [ 197, 211 ] ] }, { "plaintext": "in which is the RMS line-to-line voltage in volts.", "section_idx": 4, "section_name": "Surge impedance loading", "target_page_ids": [ 42986, 32549, 32567 ], "anchor_spans": [ [ 17, 20 ], [ 34, 41 ], [ 45, 50 ] ] }, { "plaintext": "Loaded below its SIL, the voltage at the load will be greater than the system voltage. Above it, the load voltage is depressed. The Ferranti effect describes the voltage gain towards the remote end of a very lightly loaded (or open ended) transmission line. Underground cables normally have a very low characteristic impedance, resulting in an SIL that is typically in excess of the thermal limit of the cable.", "section_idx": 4, "section_name": "Surge impedance loading", "target_page_ids": [ 14386363, 12232494 ], "anchor_spans": [ [ 132, 147 ], [ 258, 275 ] ] }, { "plaintext": "The characteristic impedance of coaxial cables (coax) is commonly chosen to be for RF and microwave applications. Coax for video applications is usually for its lower loss.", "section_idx": 5, "section_name": "Practical examples", "target_page_ids": [ 46380, 42852, 20097, 32441 ], "anchor_spans": [ [ 32, 45 ], [ 84, 86 ], [ 91, 100 ], [ 124, 129 ] ] }, { "plaintext": " Iterative impedance, characteristic impedance is a limiting case of this", "section_idx": 6, "section_name": "See also", "target_page_ids": [ 43759333 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": "Leitungstheorie", "section_idx": 8, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] } ]

[ "Electricity", "Physical_quantities", "Distributed_element_circuits", "Transmission_lines" ]

[ "surge impedance" ]

[ { "plaintext": "Chip may refer to:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Chip (food), thin sliced food, cooked until crunchy", "section_idx": 1, "section_name": "Food", "target_page_ids": [ 53645460 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Potato chip, a thin slice of potato that has been deep fried or baked until crunchy, called a \"crisp\" in some countries, such as the UK.", "section_idx": 1, "section_name": "Food", "target_page_ids": [ 24851 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Chips (hot food), fried potato batons also called french fries", "section_idx": 1, "section_name": "Food", "target_page_ids": [ 10885 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Game chips, thin deep-fried slices of potato served as an accompaniment to roast gamebirds", "section_idx": 1, "section_name": "Food", "target_page_ids": [ 65540834 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " Chocolate chip, small chunk of sweetened chocolate", "section_idx": 1, "section_name": "Food", "target_page_ids": [ 1730071 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Chip (association football), a type of football shot", "section_idx": 2, "section_name": "Sports and gaming", "target_page_ids": [ 49393827 ], "anchor_spans": [ [ 1, 28 ] ] }, { "plaintext": " Chip (golf), a type of golf shot", "section_idx": 2, "section_name": "Sports and gaming", "target_page_ids": [ 22330996 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Casino token, often referred to as a chip", "section_idx": 2, "section_name": "Sports and gaming", "target_page_ids": [ 381364 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Chip (name), a list of people and fictional characters with either the given name or nickname", "section_idx": 3, "section_name": "People and fictional characters", "target_page_ids": [ 41774590 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Chip (rapper), English hip hop recording artist born Jahmaal Noel Fyffe in 1990", "section_idx": 3, "section_name": "People and fictional characters", "target_page_ids": [ 21904185 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " King Chip (born 1986), stage name of American hip hop rapper Charles Jawanzaa Worth, formerly known as Chip tha Ripper", "section_idx": 3, "section_name": "People and fictional characters", "target_page_ids": [ 28733135 ], "anchor_spans": [ [ 1, 10 ] ] }, { "plaintext": " Chip Douglas, American songwriter, musician, and record producer Douglas Hatlelid (born 1942)", "section_idx": 3, "section_name": "People and fictional characters", "target_page_ids": [ 2698790 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Chip Taylor, stage name of American songwriter James Wesley Voight (born 1940)", "section_idx": 3, "section_name": "People and fictional characters", "target_page_ids": [ 502865 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Chip Fairway, a ring name of American professional wrestler Brett J. Keen (1972–2011)", "section_idx": 3, "section_name": "People and fictional characters", "target_page_ids": [ 49765500 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": "Chromatin immunoprecipitation (ChIP), a molecular biology method to map DNA sites", "section_idx": 4, "section_name": "Biology", "target_page_ids": [ 26419872 ], "anchor_spans": [ [ 0, 29 ] ] }, { "plaintext": "STUB1, a human gene also known as CHIP (C terminus of HSC70-Interacting Protein)", "section_idx": 4, "section_name": "Biology", "target_page_ids": [ 14754305 ], "anchor_spans": [ [ 0, 5 ] ] }, { "plaintext": " Chip, a monolithic integrated circuit without its packaging, a microchip", "section_idx": 5, "section_name": "Computing", "target_page_ids": [ 15150 ], "anchor_spans": [ [ 9, 38 ] ] }, { "plaintext": " An integrated circuit mounted on a surface mount chip carrier", "section_idx": 5, "section_name": "Computing", "target_page_ids": [ 34147043 ], "anchor_spans": [ [ 50, 62 ] ] }, { "plaintext": " Chip (CDMA), the fundamental unit of transmission in CDMA", "section_idx": 5, "section_name": "Computing", "target_page_ids": [ 8883303 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " CHIP (computer), Linux dev board built by Next Thing Co. and marketed as a miniature computer", "section_idx": 5, "section_name": "Computing", "target_page_ids": [ 48172826 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " CHIP (programming language), based on Prolog", "section_idx": 5, "section_name": "Computing", "target_page_ids": [ 3803093 ], "anchor_spans": [ [ 1, 28 ] ] }, { "plaintext": " CHIP-8, a video game programming language in the 1970s", "section_idx": 5, "section_name": "Computing", "target_page_ids": [ 1119698 ], "anchor_spans": [ [ 1, 7 ] ] }, { "plaintext": " ChucK for iPhone/iPad (ChiP), a programming language used for music synthesis", "section_idx": 5, "section_name": "Computing", "target_page_ids": [ 478750 ], "anchor_spans": [ [ 1, 6 ] ] }, { "plaintext": "Connected Home over IP (CHIP), a protocol for home automation", "section_idx": 5, "section_name": "Computing", "target_page_ids": [ 62658923 ], "anchor_spans": [ [ 0, 22 ] ] }, { "plaintext": " Chip (stock market), description of stock of a particular quality", "section_idx": 6, "section_name": "Finance", "target_page_ids": [ 40640308 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " Clearing House Interbank Payments System (CHIPS), a United States private clearing house for large-value transactions", "section_idx": 6, "section_name": "Finance", "target_page_ids": [ 3184403 ], "anchor_spans": [ [ 1, 41 ] ] }, { "plaintext": " California Highway Patrol (CHiP), a law enforcement agency of California", "section_idx": 7, "section_name": "Organizations and programs", "target_page_ids": [ 432561 ], "anchor_spans": [ [ 1, 26 ] ] }, { "plaintext": " CHIP Holding, a German-based publishing house", "section_idx": 7, "section_name": "Organizations and programs", "target_page_ids": [ 4522692 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Children's Health Insurance Program (CHIP), a US federal government program", "section_idx": 7, "section_name": "Organizations and programs", "target_page_ids": [ 635422 ], "anchor_spans": [ [ 1, 36 ] ] }, { "plaintext": " Community Housing and Infrastructure Program (CHIP), an Australian government funding program, along with its Community Development Employment Projects", "section_idx": 7, "section_name": "Organizations and programs", "target_page_ids": [ 35525049 ], "anchor_spans": [ [ 112, 153 ] ] }, { "plaintext": " Masonic Child Identification Programs, a charitable initiative by North American Masonic lodges", "section_idx": 7, "section_name": "Organizations and programs", "target_page_ids": [ 10610028 ], "anchor_spans": [ [ 1, 38 ] ] }, { "plaintext": " Clonal hematopoiesis of indeterminate potential (CHIP)", "section_idx": 8, "section_name": "Other uses", "target_page_ids": [ 53925411 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Chip, one of the mascots of the University of Colorado at Boulder", "section_idx": 8, "section_name": "Other uses", "target_page_ids": [ 289672 ], "anchor_spans": [ [ 33, 66 ] ] }, { "plaintext": " Chip language, spoken in Nigeria", "section_idx": 8, "section_name": "Other uses", "target_page_ids": [ 15946105 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " Swarf, also known as chips, the debris or waste resulting from metalworking operations", "section_idx": 8, "section_name": "Other uses", "target_page_ids": [ 10823878 ], "anchor_spans": [ [ 1, 6 ] ] }, { "plaintext": " CHIP (magazine), a German computer magazine", "section_idx": 8, "section_name": "Other uses", "target_page_ids": [ 4522663 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Chip-India, Indian edition of German computer magazine CHIP", "section_idx": 8, "section_name": "Other uses", "target_page_ids": [ 2970390 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " \"Chip Chip\", a 1961 song written by Jeff Barry, Clifford Crawford, and Arthur Resnick and performed by Gene McDaniels", "section_idx": 9, "section_name": "See also", "target_page_ids": [ 42635152 ], "anchor_spans": [ [ 2, 11 ] ] }, { "plaintext": " Chips (disambiguation)", "section_idx": 9, "section_name": "See also", "target_page_ids": [ 1136628 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": " Chipper (disambiguation)", "section_idx": 9, "section_name": "See also", "target_page_ids": [ 1182537 ], "anchor_spans": [ [ 1, 25 ] ] }, { "plaintext": " Chipping (disambiguation)", "section_idx": 9, "section_name": "See also", "target_page_ids": [ 3359226 ], "anchor_spans": [ [ 1, 26 ] ] }, { "plaintext": " Ch!pz, a Dutch band", "section_idx": 9, "section_name": "See also", "target_page_ids": [ 1905137 ], "anchor_spans": [ [ 1, 6 ] ] } ]

[]

[]

[ { "plaintext": "Chirping may refer to: ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Bird vocalization", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 369978 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Chirping, the act of signaling with chirps, signals in which the frequency increases / decreases with time", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 65635 ], "anchor_spans": [ [ 37, 42 ] ] }, { "plaintext": " Chirping, pulse compression by linear frequency modulation", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 8433728 ], "anchor_spans": [ [ 11, 28 ] ] }, { "plaintext": " Trash-talk in ice hockey", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 3232376 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " Chirp (disambiguation)", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 17433003 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": " Chirplet transform", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 1034358 ], "anchor_spans": [ [ 1, 19 ] ] } ]

[]

[]

[ { "plaintext": "Circuit may refer to:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Electrical circuit, a complete electrical network with a closed-loop giving a return path for current ", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 9559 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": " Analog circuit, uses continuous signal levels ", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 1665281 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Balanced circuit, paths are impedance-matched", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 10956197 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Circuit analysis, the process of finding the voltages across, and the currents through, every component in an electrical circuit", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 735611 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Circuit diagram, a graphical representation of an electrical circuit", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 587339 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Digital circuit, uses discrete signal levels", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 27753031 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Electronic circuit, contains \"active\" (nonlinear) electronic components capable of performing amplification, computation, and data transfer", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 8707643 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": " Asynchronous circuit, or self-timed circuit, a sequential digital logic circuit that is not governed by a clock circuit or global clock signal", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 1627162 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Integrated circuit, a set of electronic circuits on a small \"chip\" of semiconductor material", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 15150 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": " Mixed-signal integrated circuit, contains both analog and digital signals", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 1157354 ], "anchor_spans": [ [ 1, 32 ] ] }, { "plaintext": " Synchronous circuit, a digital circuit in which the changes in the state of memory elements are synchronized by a clock signal", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 1627129 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " Printed circuit board, on which electronic components are supported and connected using copper tracks on a non-conductive substrate", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 65910 ], "anchor_spans": [ [ 1, 22 ] ] }, { "plaintext": " Series and parallel circuits, two ways in which electrical components may be interconnected", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 270770 ], "anchor_spans": [ [ 1, 29 ] ] }, { "plaintext": " Simple filters, including:", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " LC circuit or tank circuit, consisting of an inductance and a capacitance", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 602264 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " RC circuit, comprises a resistance and a capacitance", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 299801 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " RL circuit, comprises a resistance and an inductance", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 1585348 ], "anchor_spans": [ [ 1, 11 ] ] }, { "plaintext": " RLC circuit, comprises a resistance, an inductance, and a capacitance", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 27174683 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Telecommunication circuit, on which information is transmitted", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 346001 ], "anchor_spans": [ [ 1, 26 ] ] }, { "plaintext": " Nonlinear circuit, a circuit with nonlinear elements.", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 6769882 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Circuit (computer theory), a theoretical structure simulating electrical and data paths", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 27753031 ], "anchor_spans": [ [ 1, 26 ] ] }, { "plaintext": " Boolean circuit, a mathematical model for digital logic circuits", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 7087423 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Integer circuit, a mathematical object of computational complexity", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 27808556 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Circuit complexity, a branch of computational complexity theory", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 7641969 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": " Cycle (graph theory), a closed path, with no other repeated vertices than the starting and ending vertices", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 168609 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Circuit of a matroid", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 65673969 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Biological neural network, in neuroscience", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 1726672 ], "anchor_spans": [ [ 1, 26 ] ] }, { "plaintext": " Hydraulic circuit, in fluid mechanics", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 1372353 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Magnetic circuit, in physics, one or more closed loop paths containing a magnetic flux", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 1115085 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Monetary circuit theory, a heterodox theory of monetary economics, also called circuitism", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 34288532 ], "anchor_spans": [ [ 1, 24 ] ] }, { "plaintext": " Pneumatic circuit, in fluid mechanics", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 8701099 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Synthetic biological circuit, in synthetic biology", "section_idx": 1, "section_name": "Science and technology", "target_page_ids": [ 33835047 ], "anchor_spans": [ [ 1, 29 ] ] }, { "plaintext": " Circuit (film), a 2001 gay-themed film set in the world of gay circuit parties", "section_idx": 2, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 6791551 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Super Circuit, a 2001 Game Boy Advance game and the third game in the Mario Kart series", "section_idx": 2, "section_name": "Arts, entertainment, and media", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " \"Circuit\", a character from the Munna Bhai film series", "section_idx": 2, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 7134992 ], "anchor_spans": [ [ 33, 43 ] ] }, { "plaintext": " Circuit, a character from Power Rangers Time Force", "section_idx": 2, "section_name": "Arts, entertainment, and media", "target_page_ids": [ 38680960 ], "anchor_spans": [ [ 12, 51 ] ] }, { "plaintext": " Circuit (LCMS), a local grouping of congregations in the Lutheran Church–Missouri Synod", "section_idx": 3, "section_name": "Church", "target_page_ids": [ 4152212 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Methodist Circuit, a form of church governance in Methodism", "section_idx": 3, "section_name": "Church", "target_page_ids": [ 18064492 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Circuit (administrative division), an administrative country subdivision in East Asia", "section_idx": 4, "section_name": "Government and law", "target_page_ids": [ 230200 ], "anchor_spans": [ [ 1, 34 ] ] }, { "plaintext": " Circuit court, the name of court systems in several common law jurisdictions", "section_idx": 4, "section_name": "Government and law", "target_page_ids": [ 597688 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " Circuit training, a form of high-intensity aerobics", "section_idx": 5, "section_name": "Sports", "target_page_ids": [ 3751384 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " ITF Pro Circuit, pro tennis tours of the International Tennis Federation", "section_idx": 5, "section_name": "Sports", "target_page_ids": [ 592311 ], "anchor_spans": [ [ 42, 73 ] ] }, { "plaintext": " ITF Men's Circuit", "section_idx": 5, "section_name": "Sports", "target_page_ids": [ 9129127 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " ITF Women's Circuit", "section_idx": 5, "section_name": "Sports", "target_page_ids": [ 25703445 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " Circuit (airfield), also called pattern, a standard path followed by aircraft when taking off or landing", "section_idx": 6, "section_name": "Transportation and racing", "target_page_ids": [ 315930 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": " Circuit, a race track or one complete traverse of a track ", "section_idx": 6, "section_name": "Transportation and racing", "target_page_ids": [ 301925 ], "anchor_spans": [ [ 12, 22 ] ] }, { "plaintext": " Formula One circuits (see list of Formula One circuits)", "section_idx": 6, "section_name": "Transportation and racing", "target_page_ids": [ 248995 ], "anchor_spans": [ [ 27, 55 ] ] }, { "plaintext": " Kart circuit, a race track designed for kart racing", "section_idx": 6, "section_name": "Transportation and racing", "target_page_ids": [ 374824 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Circuit (software), a collaboration service software by Unify", "section_idx": 7, "section_name": "Other uses", "target_page_ids": [ 19759730 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": " Circuit, slang for hangouts or events frequented by a given social circle", "section_idx": 7, "section_name": "Other uses", "target_page_ids": [ 191253 ], "anchor_spans": [ [ 61, 74 ] ] }, { "plaintext": " Circuit party, a gay dance event", "section_idx": 7, "section_name": "Other uses", "target_page_ids": [ 412555 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " Circuital, a 2011 album by My Morning Jacket", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 31483588 ], "anchor_spans": [ [ 1, 10 ] ] }, { "plaintext": " Cirkut", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 35771162 ], "anchor_spans": [ [ 1, 7 ] ] }, { "plaintext": " The Circuit (disambiguation)", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 7598689 ], "anchor_spans": [ [ 1, 29 ] ] } ]

[]

[]

[ { "plaintext": "At any point in a transmission system, the ratio of the circuit noise at that point to an arbitrary level chosen as a reference. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 46982, 346001, 3966982 ], "anchor_spans": [ [ 18, 37 ], [ 56, 63 ], [ 64, 69 ] ] }, { "plaintext": "The circuit noise level is usually expressed in dBrn0, signifying the reading of a circuit noise meter, or in dBa0, signifying circuit noise meter reading adjusted to represent an interfering effect under specified conditions. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 3966982 ], "anchor_spans": [ [ 12, 23 ] ] } ]

[ "Noise_(electronics)" ]

[]

[ { "plaintext": "Circuit reliability (also time availability) (CiR) is the percentage of time an electronic circuit was available for use in a specified period of scheduled availability. Circuit reliability is given by where T o is the circuit total outage time, Ts is the circuit total scheduled time, and T a is the circuit total available time. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 30012, 40760, 1724836 ], "anchor_spans": [ [ 72, 76 ], [ 156, 168 ], [ 179, 190 ] ] }, { "plaintext": "In addition, circuit reliability is the expected lifespan of operation of a functioning system under nominal conditions.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] } ]

[ "Electrical_engineering" ]

[]

[ { "plaintext": "In telecommunication, circuit restoration is the process by which a communications circuit is established between two users after disruption or loss of the original circuit. The loss may be widespread due to a natural disaster like an ice storm or hurricane, or local by being cut underground in construction or damaged in a thunderstorm or car accident.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 5177, 346001, 58921, 206940, 8282374, 239038, 70807, 19740545 ], "anchor_spans": [ [ 3, 20 ], [ 68, 81 ], [ 83, 90 ], [ 211, 227 ], [ 236, 245 ], [ 249, 258 ], [ 297, 309 ], [ 326, 338 ], [ 342, 354 ] ] }, { "plaintext": "Circuit restoration is usually performed in accordance with planned procedures and priorities. Restoration may be effected automatically, such as by switching to a hot standby, or manually, such as by manual patching.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 3218818, 2336638 ], "anchor_spans": [ [ 164, 175 ], [ 208, 213 ] ] } ]

[ "Communication_circuits" ]

[]

[ { "plaintext": "Circuit switching is a method of implementing a telecommunications network in which two network nodes establish a dedicated communications channel (circuit) through the network before the nodes may communicate. The circuit guarantees the full bandwidth of the channel and remains connected for the duration of the communication session. The circuit functions as if the nodes were physically connected as with an electrical circuit. Circuit switching originated in analog telephone networks where the network created a dedicated circuit between two telephones for the duration of a telephone call. It contrasts with message switching and packet switching used in modern digital networks in which the trunklines between switching centers carry data between many different nodes in the form of data packets without dedicated circuits.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 46545, 998116, 156700, 346001, 865452, 9559, 1966111, 406703, 190851, 43339, 593233, 43734 ], "anchor_spans": [ [ 48, 74 ], [ 88, 101 ], [ 124, 146 ], [ 148, 155 ], [ 314, 335 ], [ 412, 430 ], [ 471, 488 ], [ 581, 595 ], [ 615, 632 ], [ 637, 653 ], [ 699, 709 ], [ 791, 802 ] ] }, { "plaintext": "The defining example of a circuit-switched network is the early analog telephone network. When a call is made from one telephone to another, switches within the telephone exchanges create a continuous wire circuit between the two telephones, for as long as the call lasts.", "section_idx": 1, "section_name": "Description", "target_page_ids": [ 1966111, 406703, 26668156 ], "anchor_spans": [ [ 71, 88 ], [ 97, 101 ], [ 161, 179 ] ] }, { "plaintext": "In circuit switching, the bit delay is constant during a connection (as opposed to packet switching, where packet queues may cause varying and potentially indefinitely long packet transfer delays). No circuit can be degraded by competing users because it is protected from use by other callers until the circuit is released and a new connection is set up. Even if no actual communication is taking place, the channel remains reserved and protected from competing users.", "section_idx": 1, "section_name": "Description", "target_page_ids": [ 1123698 ], "anchor_spans": [ [ 173, 194 ] ] }, { "plaintext": "While circuit switching is commonly used for connecting voice circuits, the concept of a dedicated path persisting between two communicating parties or nodes can be extended to signal content other than voice. The advantage of using circuit switching is that it provides for continuous transfer without the overhead associated with packets, making maximal use of available bandwidth for that communication. One disadvantage is that it can be relatively inefficient because unused capacity guaranteed to a connection cannot be used by other connections on the same network. In addition, calls cannot be established or will be dropped if the circuit is broken. ", "section_idx": 1, "section_name": "Description", "target_page_ids": [ 43734 ], "anchor_spans": [ [ 332, 339 ] ] }, { "plaintext": "For call setup and control (and other administrative purposes), it is possible to use a separate dedicated signalling channel from the end node to the network. ISDN is one such service that uses a separate signalling channel while plain old telephone service (POTS) does not.", "section_idx": 2, "section_name": "The call", "target_page_ids": [ 65790632, 41703, 15231, 160834 ], "anchor_spans": [ [ 4, 14 ], [ 107, 117 ], [ 160, 164 ], [ 231, 258 ] ] }, { "plaintext": "The method of establishing the connection and monitoring its progress and termination through the network may also utilize a separate control channel as in the case of links between telephone exchanges which use CCS7 packet-switched signalling protocol to communicate the call setup and control information and use TDM to transport the actual circuit data.", "section_idx": 2, "section_name": "The call", "target_page_ids": [ 41691, 100098, 41796 ], "anchor_spans": [ [ 125, 149 ], [ 212, 216 ], [ 315, 318 ] ] }, { "plaintext": "Early telephone exchanges were a suitable example of circuit switching. The subscriber would ask the operator to connect to another subscriber, whether on the same exchange or via an inter-exchange link and another operator. The result was a physical electrical connection between the two subscribers' telephones for the duration of the call. The copper wire used for the connection could not be used to carry other calls at the same time, even if the subscribers were in fact not talking and the line was silent.", "section_idx": 2, "section_name": "The call", "target_page_ids": [ 26668156 ], "anchor_spans": [ [ 6, 25 ] ] }, { "plaintext": "In circuit switching, a route and its associated bandwidth is reserved from source to destination, making circuit switching relatively inefficient since capacity is reserved whether or not the connection is in continuous use. Circuit switching contrasts with message switching and packet switching. Both of these methods can make better use of available network bandwidth between multiple communication sessions under typical conditions in data communication networks.", "section_idx": 3, "section_name": "Alternatives", "target_page_ids": [ 190851, 43339 ], "anchor_spans": [ [ 259, 276 ], [ 281, 297 ] ] }, { "plaintext": "Message switching routes messages in their entirety, one hop at a time, that is, store and forward of the entire message. Packet switching divides the data to be transmitted into packets transmitted through the network independently. Instead of being dedicated to one communication session at a time, network links are shared by packets from multiple competing communication sessions, resulting in the loss of the quality of service guarantees that are provided by circuit switching.", "section_idx": 3, "section_name": "Alternatives", "target_page_ids": [ 604831, 43734 ], "anchor_spans": [ [ 81, 98 ], [ 179, 186 ] ] }, { "plaintext": "Packet switching can be based on connection-oriented communication or connection-less communication. That is, based on virtual circuits or datagrams. ", "section_idx": 3, "section_name": "Alternatives", "target_page_ids": [ 2137712, 40950 ], "anchor_spans": [ [ 33, 66 ], [ 71, 100 ] ] }, { "plaintext": "Virtual circuits use packet switching technology that emulates circuit switching, in the sense that the connection is established before any packets are transferred, and packets are delivered in order.", "section_idx": 3, "section_name": "Alternatives", "target_page_ids": [ 41851 ], "anchor_spans": [ [ 0, 16 ] ] }, { "plaintext": "Connection-less packet switching divides the data to be transmitted into packets, called datagrams, transmitted through the network independently. Each datagram is labeled with its destination and a sequence number for ordering related packets, precluding the need for a dedicated path to help the packet find its way to its destination. Each datagram is dispatched independently and each may be routed via a different path. At the destination, the original message is reordered based on the packet number to reproduce the original message. As a result, datagram packet switching networks do not require a circuit to be established and allow many pairs of nodes to communicate concurrently over the same channel.", "section_idx": 3, "section_name": "Alternatives", "target_page_ids": [ 40994 ], "anchor_spans": [ [ 89, 98 ] ] }, { "plaintext": "Multiplexing multiple telecommunications connections over the same physical conductor has been possible for a long time, but each channel on the multiplexed link was either dedicated to one call at a time, or it was idle between calls.", "section_idx": 3, "section_name": "Alternatives", "target_page_ids": [ 41389 ], "anchor_spans": [ [ 0, 12 ] ] }, { "plaintext": " Public switched telephone network (PSTN)", "section_idx": 4, "section_name": "Examples of circuit-switched networks", "target_page_ids": [ 468436 ], "anchor_spans": [ [ 1, 34 ] ] }, { "plaintext": " B channel of ISDN ", "section_idx": 4, "section_name": "Examples of circuit-switched networks", "target_page_ids": [ 521752, 15231 ], "anchor_spans": [ [ 1, 10 ], [ 14, 18 ] ] }, { "plaintext": " Circuit Switched Data (CSD) and High-Speed Circuit-Switched Data (HSCSD) service in cellular systems such as GSM", "section_idx": 4, "section_name": "Examples of circuit-switched networks", "target_page_ids": [ 959943, 959943, 12808 ], "anchor_spans": [ [ 1, 22 ], [ 33, 65 ], [ 110, 113 ] ] }, { "plaintext": " Datakit", "section_idx": 4, "section_name": "Examples of circuit-switched networks", "target_page_ids": [ 21243458 ], "anchor_spans": [ [ 1, 8 ] ] }, { "plaintext": " X.21 (Used in the German DATEX-L and Scandinavian DATEX circuit switched data network)", "section_idx": 4, "section_name": "Examples of circuit-switched networks", "target_page_ids": [ 649708 ], "anchor_spans": [ [ 1, 5 ] ] }, { "plaintext": " Optical mesh network", "section_idx": 4, "section_name": "Examples of circuit-switched networks", "target_page_ids": [ 29148156 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Clos network", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 7919595 ], "anchor_spans": [ [ 1, 13 ] ] }, { "plaintext": " Switching circuit theory", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 32182026 ], "anchor_spans": [ [ 1, 25 ] ] }, { "plaintext": " Time-driven switching", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 21802005 ], "anchor_spans": [ [ 1, 22 ] ] }, { "plaintext": " Netheads vs Bellheads by Steve Steinberg", "section_idx": 7, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " University of Virginia", "section_idx": 7, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " RFC 3439 Some Internet Architectural Guidelines and Philopsophy", "section_idx": 7, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] } ]

[ "Teletraffic", "Network_architecture", "Physical_layer_protocols" ]

[ "circuit switched", "Circuit-switched", "CS" ]

[ { "plaintext": "In electrodynamics, circular polarization of an electromagnetic wave is a polarization state in which, at each point, the electromagnetic field of the wave has a constant magnitude and is rotating at a constant rate in a plane perpendicular to the direction of the wave.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 426219, 9426, 41564, 9735 ], "anchor_spans": [ [ 3, 18 ], [ 48, 68 ], [ 74, 86 ], [ 122, 143 ] ] }, { "plaintext": "In electrodynamics, the strength and direction of an electric field is defined by its electric field vector. In the case of a circularly polarized wave, as seen in the accompanying animation, the tip of the electric field vector, at a given point in space, relates to the phase of the light as it travels through time and space. At any instant of time, the electric field vector of the wave indicates a point on a helix oriented along the direction of propagation. A circularly polarized wave can rotate in one of two possible senses: clockwise or right-handed circular polarization (RHCP) in which the electric field vector rotates in a right-hand sense with respect to the direction of propagation, and counter-clockwise or left-handed circular polarization (LHCP) in which the vector rotates in a left-hand sense.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 32533, 179924, 221536, 2850124 ], "anchor_spans": [ [ 222, 228 ], [ 414, 419 ], [ 638, 648 ], [ 800, 809 ] ] }, { "plaintext": "Circular polarization is a limiting case of elliptical polarization. The other special case is the easier-to-understand linear polarization. All three terms were coined in 1822 by Augustin-Jean Fresnel, who first reported the case of circular polarization (without yet naming it) in 1821.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 40400729, 41106, 31308010, 41316, 1141 ], "anchor_spans": [ [ 27, 40 ], [ 44, 67 ], [ 79, 91 ], [ 120, 139 ], [ 180, 201 ] ] }, { "plaintext": "The phenomenon of polarization arises as a consequence of the fact that light behaves as a two-dimensional transverse wave.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 17939, 76408 ], "anchor_spans": [ [ 72, 77 ], [ 107, 122 ] ] }, { "plaintext": "Circular polarization occurs when the two orthogonal electric field component vectors are of equal magnitude and are out of phase by exactly 90°, or one-quarter wavelength. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "On the right is an illustration of the electric field vectors of a circularly polarized electromagnetic wave. The individual electric field vectors, as well as their combined vector, have a constant magnitude, and with changing phase angle. Given that this is a plane wave, each vector represents the magnitude and direction of the electric field for an entire plane that is perpendicular to the optical axis. Specifically, given that this is a circularly polarized plane wave, these vectors indicate that the electric field, from plane to plane, has a constant strength while its direction steadily rotates. Refer to these two images in the plane wave article to better appreciate this dynamic. This light is considered to be right-hand, clockwise circularly polarized if viewed by the receiver. Since this is an electromagnetic wave, each electric field vector has a corresponding, but not illustrated, magnetic field vector that is at a right angle to the electric field vector and proportional in magnitude to it. As a result, the magnetic field vectors would trace out a second helix if displayed.", "section_idx": 1, "section_name": "General description", "target_page_ids": [ 32533, 990534, 41559, 41559, 41559, 9426, 41092, 36563, 76956, 81863 ], "anchor_spans": [ [ 54, 60 ], [ 199, 208 ], [ 262, 272 ], [ 445, 476 ], [ 618, 634 ], [ 814, 834 ], [ 841, 855 ], [ 905, 919 ], [ 940, 951 ], [ 985, 997 ] ] }, { "plaintext": "Circular polarization is often encountered in the field of optics and, in this section, the electromagnetic wave will be simply referred to as light.", "section_idx": 1, "section_name": "General description", "target_page_ids": [ 17939 ], "anchor_spans": [ [ 143, 148 ] ] }, { "plaintext": "The nature of circular polarization and its relationship to other polarizations is often understood by thinking of the electric field as being divided into two components that are perpendicular to each other. The vertical component and its corresponding plane are illustrated in blue, while the horizontal component and its corresponding plane are illustrated in green. Notice that the rightward (relative to the direction of travel) horizontal component leads the vertical component by one quarter of a wavelength, a 90° phase difference. It is this quadrature phase relationship that creates the helix and causes the points of maximum magnitude of the vertical component to correspond with the points of zero magnitude of the horizontal component, and vice versa. The result of this alignment are select vectors, corresponding to the helix, which exactly match the maxima of the vertical and horizontal components. ", "section_idx": 1, "section_name": "General description", "target_page_ids": [ 32533, 33125, 3440178, 179924 ], "anchor_spans": [ [ 160, 170 ], [ 504, 514 ], [ 551, 567 ], [ 598, 603 ] ] }, { "plaintext": "To appreciate how this quadrature phase shift corresponds to an electric field that rotates while maintaining a constant magnitude, imagine a dot traveling clockwise in a circle. Consider how the vertical and horizontal displacements of the dot, relative to the center of the circle, vary sinusoidally in time and are out of phase by one quarter of a cycle. The displacements are said to be out of phase by one quarter of a cycle because the horizontal maximum displacement (toward the left) is reached one quarter of a cycle before the vertical maximum displacement is reached. Now referring again to the illustration, imagine the center of the circle just described, traveling along the axis from the front to the back. The circling dot will trace out a helix with the displacement toward our viewing left, leading the vertical displacement. Just as the horizontal and vertical displacements of the rotating dot are out of phase by one quarter of a cycle in time, the magnitude of the horizontal and vertical components of the electric field are out of phase by one quarter of a wavelength.", "section_idx": 1, "section_name": "General description", "target_page_ids": [ 24047, 859275, 324749 ], "anchor_spans": [ [ 34, 39 ], [ 220, 233 ], [ 289, 301 ] ] }, { "plaintext": "The next pair of illustrations is that of left-handed, counterclockwise circularly polarized light when viewed by the receiver. Because it is left-handed, the rightward (relative to the direction of travel) horizontal component is now lagging the vertical component by one quarter of a wavelength, rather than leading it.", "section_idx": 1, "section_name": "General description", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "To convert circularly polarized light to the other handedness, one can use a half-waveplate. A half-waveplate shifts a given linear component of light one half of a wavelength relative to its orthogonal linear component.", "section_idx": 1, "section_name": "General description", "target_page_ids": [ 51940 ], "anchor_spans": [ [ 82, 91 ] ] }, { "plaintext": "The handedness of polarized light is reversed reflected off a surface at normal incidence. Upon such reflection, the rotation of the plane of polarization of the reflected light is identical to that of the incident field. However, with propagation now in the opposite direction, the same rotation direction that would be described as \"right-handed\" for the incident beam, is \"left-handed\" for propagation in the reverse direction, and vice versa. Aside from the reversal of handedness, the ellipticity of polarization is also preserved (except in cases of reflection by a birefringent surface).", "section_idx": 1, "section_name": "General description", "target_page_ids": [ 55054778, 174412 ], "anchor_spans": [ [ 133, 154 ], [ 572, 584 ] ] }, { "plaintext": "Note that this principle only holds strictly for light reflected at normal incidence. For instance, right circularly polarized light reflected from a dielectric surface at grazing incidence (an angle beyond the Brewster angle) will still emerge as right-handed, but elliptically, polarized. Light reflected by a metal at non-normal incidence will generally have its ellipticity changed as well. Such situations may be solved by decomposing the incident circular (or other) polarization into components of linear polarization parallel and perpendicular to the plane of incidence, commonly denoted p and s respectively. The reflected components in the p and s linear polarizations are found by applying the Fresnel coefficients of reflection, which are generally different for those two linear polarizations. Only in the special case of normal incidence, where there is no distinction between p and s, are the Fresnel coefficients for the two components identical, leading to the above property.", "section_idx": 1, "section_name": "General description", "target_page_ids": [ 40815, 24163057, 11149 ], "anchor_spans": [ [ 211, 225 ], [ 559, 577 ], [ 705, 725 ] ] }, { "plaintext": "Circularly polarized light can be converted into linearly polarized light by passing it through a quarter-waveplate. Passing linearly polarized light through a quarter-waveplate with its axes at 45° to its polarization axis will convert it to circular polarization. In fact, this is the most common way of producing circular polarization in practice. Note that passing linearly polarized light through a quarter-waveplate at an angle other than 45° will generally produce elliptical polarization.", "section_idx": 1, "section_name": "General description", "target_page_ids": [ 51940 ], "anchor_spans": [ [ 106, 115 ] ] }, { "plaintext": "Circular polarization may be referred to as right-handed or left-handed, and clockwise or anti-clockwise, depending on the direction in which the electric field vector rotates. Unfortunately, two opposing historical conventions exist.", "section_idx": 2, "section_name": "Handedness conventions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Using this convention, polarization is defined from the point of view of the source. When using this convention, left- or right-handedness is determined by pointing one's left or right thumb away from the source, in the same direction that the wave is propagating, and matching the curling of one's fingers to the direction of the temporal rotation of the field at a given point in space. When determining if the wave is clockwise or anti-clockwise circularly polarized, one again takes the point of view of the source, and while looking away from the source and in the same direction of the wave's propagation, one observes the direction of the field's spatial rotation.", "section_idx": 2, "section_name": "Handedness conventions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Using this convention, the electric field vector of a left-handed circularly polarized wave is as follows:", "section_idx": 2, "section_name": "Handedness conventions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "As a specific example, refer to the circularly polarized wave in the first animation. Using this convention, that wave is defined as right-handed because when one points one's right thumb in the same direction of the wave's propagation, the fingers of that hand curl in the same direction of the field's temporal rotation. It is considered clockwise circularly polarized because, from the point of view of the source, looking in the same direction of the wave's propagation, the field rotates in the clockwise direction. The second animation is that of left-handed or anti-clockwise light, using this same convention.", "section_idx": 2, "section_name": "Handedness conventions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "This convention is in conformity with the Institute of Electrical and Electronics Engineers (IEEE) standard and, as a result, it is generally used in the engineering community.", "section_idx": 2, "section_name": "Handedness conventions", "target_page_ids": [ 56938 ], "anchor_spans": [ [ 42, 91 ] ] }, { "plaintext": "Quantum physicists also use this convention of handedness because it is consistent with their convention of handedness for a particle's spin.", "section_idx": 2, "section_name": "Handedness conventions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Radio astronomers also use this convention in accordance with an International Astronomical Union (IAU) resolution made in 1973.", "section_idx": 2, "section_name": "Handedness conventions", "target_page_ids": [ 14878 ], "anchor_spans": [ [ 65, 103 ] ] }, { "plaintext": "In this alternative convention, polarization is defined from the point of view of the receiver. Using this convention, left- or right-handedness is determined by pointing one's left or right thumb toward the source, against the direction of propagation, and then matching the curling of one's fingers to the spatial rotation of the field.", "section_idx": 2, "section_name": "Handedness conventions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "When using this convention, in contrast to the other convention, the defined handedness of the wave matches the handedness of the screw type nature of the field in space. Specifically, if one freezes a right-handed wave in time, when one curls the fingers of one's right hand around the helix, the thumb will point in the direction of progression for the helix, given the sense of rotation. Note that, in the context of the nature of all screws and helices, it does not matter in which direction you point your thumb when determining its handedness.", "section_idx": 2, "section_name": "Handedness conventions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "When determining if the wave is clockwise or anti-clockwise circularly polarized, one again takes the point of view of the receiver and, while looking toward the source, against the direction of propagation, one observes the direction of the field's temporal rotation.", "section_idx": 2, "section_name": "Handedness conventions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Just as in the other convention, right-handedness corresponds to a clockwise rotation, and left-handedness corresponds to an anti-clockwise rotation.", "section_idx": 2, "section_name": "Handedness conventions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Many optics textbooks use this second convention. It is also used by SPIE as well as the International Union of Pure and Applied Chemistry (IUPAC).", "section_idx": 2, "section_name": "Handedness conventions", "target_page_ids": [ 2211256, 14870 ], "anchor_spans": [ [ 69, 73 ], [ 90, 139 ] ] }, { "plaintext": "As stated earlier, there is significant confusion with regards to these two conventions. As a general rule, the engineering, quantum physics, and radio astronomy communities use the first convention, in which the wave is observed from the point of view of the source. In many physics textbooks dealing with optics, the second convention is used, in which the light is observed from the point of view of the receiver.", "section_idx": 2, "section_name": "Handedness conventions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "To avoid confusion, it is good practice to specify \"as defined from the point of view of the source\" or \"as defined from the point of view of the receiver\" when discussing polarization matters.", "section_idx": 2, "section_name": "Handedness conventions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The archive of the US Federal Standard 1037C proposes two contradictory conventions of handedness.", "section_idx": 2, "section_name": "Handedness conventions", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The term \"circular polarization\" is often used erroneously to describe mixed polarity signals used mostly in FM radio (87.5 to 108.0 MHz in the USA), in which a vertical and a horizontal component are propagated simultaneously by a single or a combined array. This has the effect of producing greater penetration into buildings and difficult reception areas than a signal with just one plane of polarization. This would be an instance in which the polarization would more appropriately be called random polarization because the polarization at a receiver, although constant, will vary depending on the direction from the transmitter and other factors in the transmitting antenna design. See Stokes parameters.", "section_idx": 3, "section_name": "FM radio", "target_page_ids": [ 1607203, 1515472 ], "anchor_spans": [ [ 109, 117 ], [ 691, 708 ] ] }, { "plaintext": "The term \"FM radio\" above refers to FM broadcasting, not two-way radio (more properly called land mobile radio), which uses vertical polarization almost exclusively.", "section_idx": 3, "section_name": "FM radio", "target_page_ids": [ 1607203, 3080842 ], "anchor_spans": [ [ 36, 51 ], [ 93, 110 ] ] }, { "plaintext": "Circular dichroism (CD) is the differential absorption of left- and right-handed circularly polarized light. Circular dichroism is the basis of a form of spectroscopy that can be used to determine the optical isomerism and secondary structure of molecules.", "section_idx": 4, "section_name": "Dichroism", "target_page_ids": [ 17939, 27752, 1170166, 19555 ], "anchor_spans": [ [ 102, 107 ], [ 154, 166 ], [ 201, 218 ], [ 246, 254 ] ] }, { "plaintext": "In general, this phenomenon will be exhibited in absorption bands of any optically active molecule. As a consequence, circular dichroism is exhibited by most biological molecules, because of the dextrorotary (e.g., some sugars) and levorotary (e.g., some amino acids) molecules they contain. Noteworthy as well is that a secondary structure will also impart a distinct CD to its respective molecules. Therefore, the alpha helix, beta sheet and random coil regions of proteins and the double helix of nucleic acids have CD spectral signatures representative of their structures.", "section_idx": 4, "section_name": "Dichroism", "target_page_ids": [ 39774, 39774, 27712, 39774, 1207, 28691, 3054, 4906, 322931, 2091495, 21496 ], "anchor_spans": [ [ 73, 89 ], [ 195, 207 ], [ 220, 225 ], [ 232, 242 ], [ 255, 265 ], [ 321, 340 ], [ 416, 427 ], [ 429, 439 ], [ 444, 455 ], [ 484, 496 ], [ 500, 512 ] ] }, { "plaintext": "Also, under the right conditions, even non-chiral molecules will exhibit magnetic circular dichroism — that is, circular dichroism induced by a magnetic field.", "section_idx": 4, "section_name": "Dichroism", "target_page_ids": [ 92206 ], "anchor_spans": [ [ 73, 100 ] ] }, { "plaintext": "Circularly polarized luminescence (CPL) can occur when either a luminophore or an ensemble of luminophores is chiral. The extent to which emissions are polarized is quantified in the same way it is for circular dichroism, in terms of the dissymmetry factor, also sometimes referred to as the anisotropy factor. This value is given by:", "section_idx": 5, "section_name": "Luminescence", "target_page_ids": [ 2290742, 1170166, 92193, 1264 ], "anchor_spans": [ [ 64, 75 ], [ 110, 116 ], [ 202, 220 ], [ 292, 302 ] ] }, { "plaintext": "where corresponds to the quantum yield of left-handed circularly polarized light, and to that of right-handed light. The maximum absolute value of gem, corresponding to purely left- or right-handed circular polarization, is therefore 2. Meanwhile, the smallest absolute value that gem can achieve, corresponding to linearly polarized or unpolarized light, is zero.", "section_idx": 5, "section_name": "Luminescence", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The classical sinusoidal plane wave solution of the electromagnetic wave equation for the electric and magnetic fields is:", "section_idx": 6, "section_name": "Mathematical description", "target_page_ids": [ 151066, 324749, 2924436, 41092, 36563 ], "anchor_spans": [ [ 4, 13 ], [ 14, 24 ], [ 52, 81 ], [ 90, 98 ], [ 103, 111 ] ] }, { "plaintext": "where k is the wavenumber;", "section_idx": 6, "section_name": "Mathematical description", "target_page_ids": [ 164570 ], "anchor_spans": [ [ 15, 25 ] ] }, { "plaintext": "is the angular frequency of the wave; is an orthogonal matrix whose columns span the transverse x-y plane; and is the speed of light.", "section_idx": 6, "section_name": "Mathematical description", "target_page_ids": [ 199829, 28736 ], "anchor_spans": [ [ 7, 24 ], [ 121, 135 ] ] }, { "plaintext": "Here,", "section_idx": 6, "section_name": "Mathematical description", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "is the amplitude of the field, and", "section_idx": 6, "section_name": "Mathematical description", "target_page_ids": [ 37649 ], "anchor_spans": [ [ 7, 16 ] ] }, { "plaintext": "is the normalized Jones vector in the x-y plane.", "section_idx": 6, "section_name": "Mathematical description", "target_page_ids": [ 16565 ], "anchor_spans": [ [ 18, 30 ] ] }, { "plaintext": "If is rotated by radians with respect to and the x amplitude equals the y amplitude, the wave is circularly polarized. The Jones vector is:", "section_idx": 6, "section_name": "Mathematical description", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "where the plus sign indicates left circular polarization, and the minus sign indicates right circular polarization. In the case of circular polarization, the electric field vector of constant magnitude rotates in the x-y plane.", "section_idx": 6, "section_name": "Mathematical description", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "If basis vectors are defined such that:", "section_idx": 6, "section_name": "Mathematical description", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "and:", "section_idx": 6, "section_name": "Mathematical description", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "then the polarization state can be written in the \"R-L basis\" as:", "section_idx": 6, "section_name": "Mathematical description", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "where:", "section_idx": 6, "section_name": "Mathematical description", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "and:", "section_idx": 6, "section_name": "Mathematical description", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "A number of different types of antenna elements can be used to produce circularly polarized (or nearly so) radiation; following Balanis, one can use dipole elements:", "section_idx": 7, "section_name": "Antennae", "target_page_ids": [ 465156 ], "anchor_spans": [ [ 149, 164 ] ] }, { "plaintext": "\"... two crossed dipoles provide the two orthogonal field components.... If the two dipoles are identical, the field intensity of each along zenith ... would be of the same intensity. Also, if the two dipoles were fed with a 90° degree time-phase difference (phase quadrature), the polarization along zenith would be circular.... One way to obtain the 90° time-phase difference between the two orthogonal field components, radiated respectively by the two dipoles, is by feeding one of the two dipoles with a transmission line which is 1/4 wavelength longer or shorter than that of the other,\" p.80;", "section_idx": 7, "section_name": "Antennae", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "or helical elements:", "section_idx": 7, "section_name": "Antennae", "target_page_ids": [ 465078 ], "anchor_spans": [ [ 3, 19 ] ] }, { "plaintext": "\"To achieve circular polarization [in axial or end-fire mode] ... the circumference C of the helix must be ... with C/wavelength = 1 near optimum, and the spacing about S = wavelength/4,\" p.571;", "section_idx": 7, "section_name": "Antennae", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "or patch elements:", "section_idx": 7, "section_name": "Antennae", "target_page_ids": [ 2415892 ], "anchor_spans": [ [ 3, 17 ] ] }, { "plaintext": "\"... circular and elliptical polarizations can be obtained using various feed arrangements or slight modifications made to the elements.... Circular polarization can be obtained if two orthogonal modes are excited with a 90° time-phase difference between them. This can be accomplished by adjusting the physical dimensions of the patch.... For a square patch element, the easiest way to excite ideally circular polarization is to feed the element at two adjacent edges.... The quadrature phase difference is obtained by feeding the element with a 90° power divider,\" p.859.", "section_idx": 7, "section_name": "Antennae", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "In the quantum mechanical view, light is composed of photons. Polarization is a manifestation of the spin angular momentum of light. More specifically, in quantum mechanics, the direction of spin of a photon is tied to the handedness of the circularly polarized light, and the spin of a beam of photons is similar to the spin of a beam of particles, such as electrons.", "section_idx": 8, "section_name": "In quantum mechanics", "target_page_ids": [ 25202, 23535, 33179436 ], "anchor_spans": [ [ 7, 25 ], [ 53, 60 ], [ 101, 131 ] ] }, { "plaintext": "Only a few mechanisms in nature are known to systematically produce circularly polarized light. In 1911, Albert Abraham Michelson discovered that light reflected from the golden scarab beetle Chrysina resplendens is preferentially left-polarized. Since then, circular polarization has been measured in several other scarab beetles such as Chrysina gloriosa, as well as some crustaceans such as the mantis shrimp. In these cases, the underlying mechanism is the molecular-level helicity of the chitinous cuticle.", "section_idx": 9, "section_name": "In nature", "target_page_ids": [ 17939, 92733, 24558168, 72276, 24381804, 40119056, 297924, 171104, 18952748 ], "anchor_spans": [ [ 89, 94 ], [ 105, 129 ], [ 192, 212 ], [ 316, 330 ], [ 339, 356 ], [ 374, 384 ], [ 398, 411 ], [ 493, 499 ], [ 503, 510 ] ] }, { "plaintext": "The bioluminescence of the larvae of fireflies is also circularly polarized, as reported in 1980 for the species Photuris lucicrescens and Photuris versicolor. For fireflies, it is more difficult to find a microscopic explanation for the polarization, because the left and right lanterns of the larvae were found to emit polarized light of opposite senses. The authors suggest that the light begins with a linear polarization due to inhomogeneities inside aligned photocytes, and it picks up circular polarization while passing through linearly birefringent tissue.", "section_idx": 9, "section_name": "In nature", "target_page_ids": [ 203711, 50357, 60996, 805856, 48246261, 41316, 7097494, 174412 ], "anchor_spans": [ [ 4, 19 ], [ 27, 32 ], [ 37, 45 ], [ 113, 134 ], [ 139, 158 ], [ 406, 425 ], [ 464, 473 ], [ 545, 557 ] ] }, { "plaintext": "Water-air interfaces provide another source of circular polarization. Sunlight that gets scattered back up towards the surface is linearly polarized. If this light is then totally internally reflected back down, its vertical component undergoes a phase shift. To an underwater observer looking up, the faint light outside Snell's window therefore is (partially) circularly polarized.", "section_idx": 9, "section_name": "In nature", "target_page_ids": [ 30426, 9288958 ], "anchor_spans": [ [ 172, 200 ], [ 322, 336 ] ] }, { "plaintext": "Weaker sources of circular polarization in nature include multiple scattering by linear polarizers, as in the circular polarization of starlight, and selective absorption by circularly dichroic media.", "section_idx": 9, "section_name": "In nature", "target_page_ids": [ 92193 ], "anchor_spans": [ [ 174, 193 ] ] }, { "plaintext": "Radio emission from stars and pulsars can be strongly circularly polarized.", "section_idx": 9, "section_name": "In nature", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Two species of mantis shrimp have been reported to be able to detect circular polarized light.", "section_idx": 9, "section_name": "In nature", "target_page_ids": [ 297924 ], "anchor_spans": [ [ 15, 28 ] ] }, { "plaintext": "Polarizer", "section_idx": 10, "section_name": "See also", "target_page_ids": [ 2722105 ], "anchor_spans": [ [ 0, 9 ] ] }, { "plaintext": "3D film", "section_idx": 10, "section_name": "See also", "target_page_ids": [ 246007 ], "anchor_spans": [ [ 0, 7 ] ] }, { "plaintext": "Chirality", "section_idx": 10, "section_name": "See also", "target_page_ids": [ 32703814 ], "anchor_spans": [ [ 0, 9 ] ] }, { "plaintext": "Sinusoidal plane-wave solutions of the electromagnetic wave equation", "section_idx": 10, "section_name": "See also", "target_page_ids": [ 6420246 ], "anchor_spans": [ [ 0, 68 ] ] }, { "plaintext": "Starlight polarization", "section_idx": 10, "section_name": "See also", "target_page_ids": [ 28996756 ], "anchor_spans": [ [ 0, 22 ] ] }, { "plaintext": "Waveplate", "section_idx": 10, "section_name": "See also", "target_page_ids": [ 51940 ], "anchor_spans": [ [ 0, 9 ] ] }, { "plaintext": " Circularly polarized light: beetles and displays", "section_idx": 12, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Article on the mantis shrimp and circular polarization", "section_idx": 12, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Animation of Circular Polarization (on YouTube)", "section_idx": 12, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Comparison of Circular Polarization with Linear and Elliptical Polarizations (YouTube Animation)", "section_idx": 12, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Reversal of handedness of circularly polarized light by mirror. A demonstration – simple, cheap & instructive", "section_idx": 12, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] } ]

[ "Polarization_(waves)", "Stellar_astronomy", "Astrophysics" ]

[]

[ { "plaintext": "A circulator is a passive, non-reciprocal three- or four-port device that only allows a microwave or radio-frequency signal to exit through the port directly after the one it entered. Optical circulators have similar behavior. Ports are where an external waveguide or transmission line, such as a microstrip line or a coaxial cable, connects to the device. For a three-port circulator, a signal applied to port 1 only comes out of port 2; a signal applied to port 2 only comes out of port 3; a signal applied to port 3 only comes out of port 1, and so on. An ideal three-port circulator has the following scattering matrix:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 30874071, 64719459, 42920842, 20097, 42852, 6310882, 3854225, 41811, 2022356, 46380, 1972332 ], "anchor_spans": [ [ 18, 25 ], [ 31, 41 ], [ 57, 61 ], [ 88, 97 ], [ 101, 116 ], [ 184, 202 ], [ 255, 264 ], [ 268, 285 ], [ 297, 307 ], [ 318, 331 ], [ 605, 622 ] ] }, { "plaintext": "Depending on the materials involved, circulators fall into two main categories: ferrite circulators and nonferrite circulators.", "section_idx": 1, "section_name": "Types", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Ferrite circulators are radio-frequency circulators which employ magnetized microwave ferrite materials. They fall into two main classes: differential phase shift circulators and junction circulators, both of which are based on cancellation of waves propagating over two different paths in or near magnetized ferrite material. Waveguide circulators may be of either type, while more compact devices based on stripline are usually of the junction type. Two or more junction circulators can be combined in a single component to give four or more ports. Typically permanent magnets produce a static magnetic bias in the microwave ferrite material. Ferrimagnetic garnet crystal is used in optical circulators.", "section_idx": 1, "section_name": "Types", "target_page_ids": [ 4269572, 216650, 37506, 6310882 ], "anchor_spans": [ [ 408, 417 ], [ 645, 658 ], [ 659, 665 ], [ 685, 703 ] ] }, { "plaintext": "Junction type stripline circulators utilize two ferrite disks above and below the stripline. These ferrites are circularly magnetized in opposite directions. They form two separate resonators with the stripline disk between them. The static magnetic bias alters the effective permeabilities in the top and bottom ferrites. The ferrite whose circular magnetization is in the same direction as the resultant electron spin precession, will see a permeability increase. The ferrite that is magnetized opposite the electron spin precession will see a permeability decrease. These changing permeabilities result in resonant frequency shifts of the two resonators previously mentioned. The operating frequency is set between the two resonances such that the impedance angle of both resonators is set to 30 degrees (for a three port implementation). The ferrite with the higher permeability will have a higher resonance frequency and an inductive reactance component. The lower permeability ferrite has a lower resonance and capacitive reactance component. These circulator types operate based on faraday rotation. Wave cancellation occurs when waves propagate with and against the circulation direction. An incident wave arriving at any port is split equally into two waves. They propagate in each direction around the circulator with different phase velocities. When they arrive at the output port they have different phase relationships and thus combine accordingly. This combination of waves propagating at different phase velocities is how junction circulators fundamentally operate. ", "section_idx": 1, "section_name": "Types", "target_page_ids": [ 518692 ], "anchor_spans": [ [ 1089, 1105 ] ] }, { "plaintext": "Though ferrite circulators can provide good \"forward\" signal circulation while suppressing greatly the \"reverse\" circulation, their major shortcomings, especially at low frequencies, are the bulky sizes and the narrow bandwidths.", "section_idx": 1, "section_name": "Types", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Early work on nonferrite circulators includes active circulators using transistors that are non-reciprocal in nature. In contrast to ferrite circulators which are passive devices, active circulators require power. Major issues associated with transistor-based active circulators are the power limitation and the signal-to-noise degradation, which are critical when it is used as a duplexer for sustaining the strong transmit power and clean reception of the signal from the antenna.", "section_idx": 1, "section_name": "Types", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Varactors offer one solution. One study employed a structure similar to a time-varying transmission line with the effective nonreciprocity triggered by a one-direction propagating carrier pump. This is like an AC-powered active circulator. The research claimed to be able to achieve positive gain and low noise for receiving path and broadband nonreciprocity. Another study used resonance with nonreciprocity triggered by angular-momentum biasing, which more closely mimics the way that signals passively circulate in a ferrite circulator.", "section_idx": 1, "section_name": "Types", "target_page_ids": [ 231506 ], "anchor_spans": [ [ 0, 8 ] ] }, { "plaintext": "In 1964, Mohr presented and experimentally demonstrated a circulator based on transmission lines and switches. In April, 2016 a research team significantly extended this concept, presenting an integrated circuit circulator based on N-path filter concepts. It offers the potential for full-duplex communication (transmitting and receiving at the same time with a single shared antenna over a single frequency). The device uses capacitors and a clock and is much smaller than conventional devices.", "section_idx": 1, "section_name": "Types", "target_page_ids": [ 15150 ], "anchor_spans": [ [ 193, 211 ] ] }, { "plaintext": "When one port of a three-port circulator is terminated in a matched load, it can be used as an isolator, since a signal can travel in only one direction between the remaining ports. An isolator is used to shield equipment on its input side from the effects of conditions on its output side; for example, to prevent a microwave source being detuned by a mismatched load.", "section_idx": 2, "section_name": "Applications", "target_page_ids": [ 22949908 ], "anchor_spans": [ [ 95, 103 ] ] }, { "plaintext": "In radar, circulators are used as a type of duplexer, to route signals from the transmitter to the antenna and from the antenna to the receiver, without allowing signals to pass directly from transmitter to receiver. The alternative type of duplexer is a transmit-receive switch (TR switch) that alternates between connecting the antenna to the transmitter and to the receiver. The use of chirped pulses and a high dynamic range may lead to temporal overlap of the sent and received pulses, however, requiring a circulator for this function.", "section_idx": 2, "section_name": "Applications", "target_page_ids": [ 25676, 41077, 61164, 187317, 491851 ], "anchor_spans": [ [ 3, 8 ], [ 44, 52 ], [ 80, 91 ], [ 99, 106 ], [ 135, 143 ] ] }, { "plaintext": "In the future-generation cellular communication, people talk about full-duplex radios, where signals can be simultaneously transmitted and received at the same frequency. Given the currently limited, crowded spectrum resource, full-duplexing can directly benefit the wireless communication by twice of the data throughput speed. Currently, the wireless communication is still performed with \"half-duplex\", where either the signals are transmitted or received at different time frames, if at the same frequency (typically in radar), or the signals are simultaneously transmitted and received at different frequencies (realized by a set of filters called a diplexer).", "section_idx": 2, "section_name": "Applications", "target_page_ids": [ 735672 ], "anchor_spans": [ [ 25, 47 ] ] }, { "plaintext": "A reflection amplifier is a type of microwave amplifier circuit utilizing negative differential resistance diodes such as tunnel diodes and Gunn diodes. Negative differential resistance diodes can amplify signals, and often perform better at microwave frequencies than two-port devices. However, since the diode is a one-port (two terminal) device, a nonreciprocal component is needed to separate the outgoing amplified signal from the incoming input signal. By using a 3-port circulator with the signal input connected to one port, the biased diode connected to a second, and the output load connected to the third, the output and input can be uncoupled.", "section_idx": 2, "section_name": "Applications", "target_page_ids": [ 237770, 237770, 530655, 1290862 ], "anchor_spans": [ [ 2, 22 ], [ 74, 106 ], [ 122, 134 ], [ 140, 150 ] ] }, { "plaintext": " Circulators and Isolators", "section_idx": 5, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " RF Circulators what they are, different types, how they work, etc.", "section_idx": 5, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] } ]

[ "Microwave_technology", "Radio_technology", "Telecommunications_equipment" ]

[]

[ { "plaintext": "Cladding is an outer layer of material covering another. It may refer to the following:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Cladding (boiler), the layer of insulation and outer wrapping around a boiler shell", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 24541786 ], "anchor_spans": [ [ 0, 17 ] ] }, { "plaintext": "Cladding (construction), materials applied to the exterior of buildings", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 29821556 ], "anchor_spans": [ [ 0, 23 ] ] }, { "plaintext": "Wall cladding, exterior material applied to the walls of a building", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 740818 ], "anchor_spans": [ [ 0, 13 ] ] }, { "plaintext": "Copper cladding, applying copper to the exterior of buildings", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 19696006 ], "anchor_spans": [ [ 0, 15 ] ] }, { "plaintext": "Rainscreen cladding, an exterior wall detail to create a capillary break and to allow drainage and evaporation of water", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 21779320 ], "anchor_spans": [ [ 0, 10 ] ] }, { "plaintext": "Cladding (fiber optics), fiber optics property to contain light in the core of the fiber by total internal reflection ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 29821546 ], "anchor_spans": [ [ 0, 23 ] ] }, { "plaintext": "Cladding (metalworking), a bonding together of dissimilar metals", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 29821539 ], "anchor_spans": [ [ 0, 23 ] ] }, { "plaintext": "Cladding (nuclear fuel), the outer layer of the fuel rods, standing between the coolant and the nuclear fuel", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 2046416 ], "anchor_spans": [ [ 0, 23 ] ] }, { "plaintext": "CLAD (disambiguation)", "section_idx": 1, "section_name": "See also", "target_page_ids": [ 3310202 ], "anchor_spans": [ [ 0, 21 ] ] } ]

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[ { "plaintext": "Clearing may refer to:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Clearing (album), a 2001 album by Fred Frith", "section_idx": 1, "section_name": "Arts and media", "target_page_ids": [ 9786393 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " The Clearing (film), a 2004 drama film", "section_idx": 1, "section_name": "Arts and media", "target_page_ids": [ 1141059 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " The Clearing (EP), a 2006 EP by Weatherbox", "section_idx": 1, "section_name": "Arts and media", "target_page_ids": [ 10324365 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " The Clearing (Sleep for Sleepers album), 2009", "section_idx": 1, "section_name": "Arts and media", "target_page_ids": [ 47044428 ], "anchor_spans": [ [ 1, 40 ] ] }, { "plaintext": " The Clearing (Locrian album), 2011", "section_idx": 1, "section_name": "Arts and media", "target_page_ids": [ 53079862 ], "anchor_spans": [ [ 1, 29 ] ] }, { "plaintext": " The Clearing (Homeland), an episode of the American television series Homeland", "section_idx": 1, "section_name": "Arts and media", "target_page_ids": [ 37616158 ], "anchor_spans": [ [ 1, 24 ] ] }, { "plaintext": " The Clearing (podcast), a 2019 true crime podcast", "section_idx": 1, "section_name": "Arts and media", "target_page_ids": [ 61875829 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": " Clearing (forest), a tract of land with few or no trees in the middle of a wooded area", "section_idx": 2, "section_name": "Ecology", "target_page_ids": [ 4425382 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " Clearing (geography), the process by which vegetation is permanently removed", "section_idx": 2, "section_name": "Ecology", "target_page_ids": [ 4425405 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Deforestation, the clearing away of trees to make farmland", "section_idx": 2, "section_name": "Ecology", "target_page_ids": [ 8103 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " Clearing (finance), the process of settling a transaction after committing to it", "section_idx": 3, "section_name": "Economics and finance", "target_page_ids": [ 1341179 ], "anchor_spans": [ [ 1, 19 ] ] }, { "plaintext": " Market clearing, the matching of supply and demand via price movement", "section_idx": 3, "section_name": "Economics and finance", "target_page_ids": [ 813411 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " Clearing, Chicago, a community area in Illinois, U.S.", "section_idx": 4, "section_name": "Other uses", "target_page_ids": [ 1880139 ], "anchor_spans": [ [ 1, 18 ] ] }, { "plaintext": " The Clearing (Ellison Bay, Wisconsin), also known as The Clearing Folk School", "section_idx": 4, "section_name": "Other uses", "target_page_ids": [ 35630577 ], "anchor_spans": [ [ 1, 38 ] ] }, { "plaintext": " Clearing (telecommunications), the disconnecting of a call", "section_idx": 4, "section_name": "Other uses", "target_page_ids": [ 3322453 ], "anchor_spans": [ [ 1, 30 ] ] }, { "plaintext": " Yarn clearing, in textile industry", "section_idx": 4, "section_name": "Other uses", "target_page_ids": [ 32424579 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " Clearing, a practice in Scientology", "section_idx": 4, "section_name": "Other uses", "target_page_ids": [ 2353513 ], "anchor_spans": [ [ 13, 36 ] ] }, { "plaintext": " Clearing, a process used by the UK's Universities and Colleges Admissions Service (UCAS)", "section_idx": 4, "section_name": "Other uses", "target_page_ids": [ 422715 ], "anchor_spans": [ [ 1, 9 ] ] }, { "plaintext": " Clear (disambiguation)", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 2353564 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": " Clearance (disambiguation)", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 2689568 ], "anchor_spans": [ [ 1, 27 ] ] } ]

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[ { "plaintext": "Thomas Latimer (Peter) Cleave (1906–1983) was a surgeon captain who researched the negative health effects of consuming refined carbohydrate (notably sugar and white flour) which would not have been available during early human evolution. Known as 'Peter' to his friends and colleagues, Cleave was born in Exeter in 1906, and educated at Clifton College. Between 1922 and 1927, he attended medical schools at the Bristol Royal Infirmary, and St Mary's Hospital, London, where he was an academic prodigy winning prize after prize and qualifying at the early age of 21, having passed his primary FRCS examination at the age of 18 and ultimately achieving MRCS and LRCP.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 1976739, 27712, 56232, 10326, 440948, 3906749, 1142128 ], "anchor_spans": [ [ 83, 105 ], [ 150, 155 ], [ 160, 171 ], [ 222, 237 ], [ 338, 353 ], [ 413, 436 ], [ 442, 468 ] ] }, { "plaintext": "At Bristol, one of his teachers was Rendle Short, who had proposed that appendicitis is caused by a lack of cellulose in the diet (it is worth noting, perhaps, from a biographical perspective, that Cleave's sister had died at the age of eight years from a perforated appendix). Charles Darwin's writings provided the intellectual framework to Cleave's lifelong engagement with the relationship between diet and health, built upon the premise that the human body is ill-adapted to the diet of modern (western) man.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Cleave's interest focussed on preventative medicine where he observed the harmful effects of the overconsumption of refined carbohydrates such as sugar and refined flour which he called 'The Saccharine Disease'. He noticed that the saccharine manifestations did not occur in wild creatures or among primitive people living on traditional unrefined food.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "He considered refined carbohydrates (white flour and sugar) to be the most transformed food, and therefore the most dangerous. After completing his medical training, Cleave entered the Royal Navy in 1927 as Surgeon Lieutenant.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Between 1938 and 1940, he served as Medical Specialist at RN Hospital, Hong Kong. It was during his war service, in 1941, whilst on the battleship King George V, that he acquired his naval nickname 'the bran man' when he had sacks of bran brought on board to combat the common occurrence of constipation amongst sailors. Cleave's intention was 'to give them bowel movements as efficient as the guns they fired.' The ship assisted in the sinking of the Bismarck. Cleave was on the bridge as the Bismarck was going down and a fellow officer exclaimed to him 'Well done Doc, you deserve a medal, our bowels were working like clockwork!’", "section_idx": 1, "section_name": "Military career", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Following war service, he worked at Royal Naval Hospitals in Chatham (1945–1948), Malta (1949–1951) and Plymouth (1952–1953). He retired from the Royal Navy in 1962 as Surgeon Captain, having finished his naval career as Director of Medical Research at the RN Medical School", "section_idx": 1, "section_name": "Military career", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Cleaves unique contribution to medical thought was his realisation that three mechanisms were at work when refined carbohydrates are eaten; fibre depletion, over-consumption and protein stripping, with over-consumption being the most serious.", "section_idx": 2, "section_name": "Post-military career", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "In 1969, Dr. Cleave brought public attention to the low amount of dietary fiber in modern diets that had become rich in processed ingredients. His work was bolstered by the supporting work of Dr. Denis Burkitt.", "section_idx": 2, "section_name": "Post-military career", "target_page_ids": [ 6235577 ], "anchor_spans": [ [ 192, 209 ] ] }, { "plaintext": "In 1979, Cleave was awarded both the Harben gold medal of the Royal Institute of Public Health and Hygiene and the Gilbert Blane medal for naval medicine by the Royal College of Physicians and Surgeons. Dr. Cleave was a 2009 inductee into the Orthomolecular Medicine Hall of Fame.", "section_idx": 3, "section_name": "Awards and honors", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Cleave published during his lifetime:", "section_idx": 4, "section_name": "Publications", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Cleave T.L. A Molecular Conception of Organisms and Neoplasms. Bristol: John Wright, 1932.", "section_idx": 4, "section_name": "Publications", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Cleave T.L. The Neglect of Natural Principles in Current Medical Practice. J Roy Nav Med Serv 1956; 42/2: 55–63.", "section_idx": 4, "section_name": "Publications", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Cleave T.L. Fat Consumption and Coronary Heart Disease. Bristol: John Wright, 1957.", "section_idx": 4, "section_name": "Publications", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Cleave T.L The Causation of Varicose Veins. Bristol: John Wright, 1960.", "section_idx": 4, "section_name": "Publications", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Cleave T.L Peptic Ulcer. Bristol: John Wright, 1962.", "section_idx": 4, "section_name": "Publications", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Cleave T.L, Campbell C. Diabetes, Coronary Thrombosis and the Saccharine Disease. Bristol: John Wright, 1966.", "section_idx": 4, "section_name": "Publications", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Cleave T.L. The Saccharine Disease. Bristol: John Wright, 1974.", "section_idx": 4, "section_name": "Publications", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Cleave T.L. Over-consumption. Now the most dangerous cause of disease in Westernised countries. Publ Hlth, London, 1977; 91: 127–131.", "section_idx": 4, "section_name": "Publications", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Weston Price", "section_idx": 5, "section_name": "See also", "target_page_ids": [ 7020762 ], "anchor_spans": [ [ 0, 12 ] ] }, { "plaintext": " Biography", "section_idx": 7, "section_name": "Sources", "target_page_ids": [], "anchor_spans": [] } ]

[ "People_educated_at_Clifton_College", "1906_births", "1983_deaths", "Royal_Navy_officers_of_World_War_II", "20th-century_English_medical_doctors", "Royal_Navy_Medical_Service_officers" ]

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[ { "plaintext": "Clipping may refer to:", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Clipping (morphology), the formation of a new word by shortening it, e.g. \"ad\" from \"advertisement\"", "section_idx": 1, "section_name": "Words", "target_page_ids": [ 2263849 ], "anchor_spans": [ [ 1, 22 ] ] }, { "plaintext": " Clipping (phonetics), shortening the articulation of a speech sound, usually a vowel", "section_idx": 1, "section_name": "Words", "target_page_ids": [ 1950506 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Clipping (publications), the cutting-out of articles from a paper publication", "section_idx": 1, "section_name": "Words", "target_page_ids": [ 1932703 ], "anchor_spans": [ [ 1, 24 ] ] }, { "plaintext": " Coin clipping, shaving off a small portion of precious metal for profit", "section_idx": 2, "section_name": "Science and technology", "target_page_ids": [ 1932700 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " Clipping (computer graphics), only drawing things that will be visible to the viewer", "section_idx": 2, "section_name": "Science and technology", "target_page_ids": [ 1932701 ], "anchor_spans": [ [ 1, 29 ] ] }, { "plaintext": " Noclip mode, or \"Noclipping\", when the player or another object in a video game unrealistically passes through another object", "section_idx": 2, "section_name": "Science and technology", "target_page_ids": [ 41568624 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Clipping (gardening), pruning, removing unwanted portions from a plant", "section_idx": 2, "section_name": "Science and technology", "target_page_ids": [ 1932702 ], "anchor_spans": [ [ 1, 21 ] ] }, { "plaintext": " Clipping (medicine), surgical treatment used to treat an aneurysm", "section_idx": 2, "section_name": "Science and technology", "target_page_ids": [ 3738777 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " Clipping (signal processing), a form of distortion that limits a signal once it exceeds a threshold. Some forms include:", "section_idx": 2, "section_name": "Science and technology", "target_page_ids": [ 11351749 ], "anchor_spans": [ [ 1, 29 ] ] }, { "plaintext": " Clipping (audio), the clipping of the top and bottom of a sound wave, referred to as \"distortion\" or \"overdrive\"", "section_idx": 2, "section_name": "Science and technology", "target_page_ids": [ 3375566 ], "anchor_spans": [ [ 1, 17 ] ] }, { "plaintext": " Clipping (photography), the clipping of overexposed area by digital cameras and film", "section_idx": 2, "section_name": "Science and technology", "target_page_ids": [ 6165436 ], "anchor_spans": [ [ 1, 23 ] ] }, { "plaintext": " Soft clipping", "section_idx": 2, "section_name": "Science and technology", "target_page_ids": [ 3951487 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " Horse clipping, trimming all or part of a horse's fur horse short", "section_idx": 3, "section_name": "Animals", "target_page_ids": [ 10630614 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Sheep shearing", "section_idx": 3, "section_name": "Animals", "target_page_ids": [ 1297137 ], "anchor_spans": [ [ 1, 15 ] ] }, { "plaintext": " Wing clipping, trimming a bird's primary flight feathers to disable flight", "section_idx": 3, "section_name": "Animals", "target_page_ids": [ 317517 ], "anchor_spans": [ [ 1, 14 ] ] }, { "plaintext": " Clipping (climbing), the process of protecting against a fall", "section_idx": 4, "section_name": "Sports", "target_page_ids": [ 367975 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " Clipping (gridiron football), a penalty in gridiron football", "section_idx": 4, "section_name": "Sports", "target_page_ids": [ 34409964 ], "anchor_spans": [ [ 1, 29 ] ] }, { "plaintext": " Clipping (ice hockey), hitting an opposing player below the knees", "section_idx": 4, "section_name": "Sports", "target_page_ids": [ 2328675 ], "anchor_spans": [ [ 1, 22 ] ] }, { "plaintext": " Clipping the church, an ancient custom", "section_idx": 5, "section_name": "Other uses", "target_page_ids": [ 19653064 ], "anchor_spans": [ [ 1, 20 ] ] }, { "plaintext": " Clipping (band), an experimental hip-hop group", "section_idx": 5, "section_name": "Other uses", "target_page_ids": [ 43107653 ], "anchor_spans": [ [ 1, 16 ] ] }, { "plaintext": " CLPPNG, their debut album", "section_idx": 5, "section_name": "Other uses", "target_page_ids": [ 45162926 ], "anchor_spans": [ [ 1, 7 ] ] }, { "plaintext": " Clip (disambiguation)", "section_idx": 6, "section_name": "See also", "target_page_ids": [ 1538170 ], "anchor_spans": [ [ 1, 22 ] ] } ]

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[ { "plaintext": "Closed captioning (CC) and subtitling are both processes of displaying text on a television, video screen, or other visual display to provide additional or interpretive information. Both are typically used as a transcription of the audio portion of a program as it occurs (either verbatim or in edited form), sometimes including descriptions of non-speech elements. Other uses have included providing a textual alternative language translation of a presentation's primary audio language that is usually burned-in (or \"open\") to the video and unselectable.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 7224224, 226990, 29831, 7677, 167550, 18994087, 19508643 ], "anchor_spans": [ [ 27, 37 ], [ 71, 75 ], [ 81, 91 ], [ 93, 105 ], [ 211, 224 ], [ 232, 237 ], [ 251, 258 ] ] }, { "plaintext": "HTML5 defines subtitles as a \"transcription or translation of the dialogue when sound is available but not understood\" by the viewer (for example, dialogue in a foreign language) and captions as a \"transcription or translation of the dialogue, sound effects, relevant musical cues, and other relevant audio information when sound is unavailable or not clearly audible\" (for example, when audio is muted or the viewer is deaf or hard of hearing).", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 7966125, 1094802, 42029762, 49604 ], "anchor_spans": [ [ 0, 5 ], [ 161, 177 ], [ 420, 424 ], [ 428, 443 ] ] }, { "plaintext": "The term \"closed\" (versus \"open\") indicates that the captions are not visible until activated by the viewer, usually via the remote control or menu option. On the other hand, \"open\", \"burned-in\", \"baked on\", \"hard-coded\", or simply \"hard\" captions are visible to all viewers as they are embedded in the video.", "section_idx": 1, "section_name": "Terminology", "target_page_ids": [ 105803 ], "anchor_spans": [ [ 125, 139 ] ] }, { "plaintext": "In the United States and Canada, the terms \"subtitles\" and \"captions\" have different meanings. Subtitles assume the viewer can hear but cannot understand the language or accent, or the speech is not entirely clear, so they transcribe only dialogue and some on-screen text. Captions aim to describe to the deaf and hard of hearing all significant audio content—spoken dialogue and non-speech information such as the identity of speakers and, occasionally, their manner of speaking—along with any significant music or sound effects using words or symbols. Also, the term closed caption has come to be used to also refer to the North American EIA-608 encoding that is used with NTSC-compatible video.", "section_idx": 1, "section_name": "Terminology", "target_page_ids": [ 7224224, 18839, 44187, 1154851 ], "anchor_spans": [ [ 95, 104 ], [ 507, 512 ], [ 516, 528 ], [ 640, 647 ] ] }, { "plaintext": "The United Kingdom, Ireland, and most other countries do not distinguish between subtitles and closed captions and use \"subtitles\" as the general term. The equivalent of \"captioning\" is usually referred to as \"subtitles for the hard of hearing\". Their presence is referenced on screen by notation which says \"Subtitles\", or previously \"Subtitles 888\" or just \"888\" (the latter two are in reference to the conventional videotext channel for captions), which is why the term subtitle is also used to refer to the Ceefax-based videotext encoding that is used with PAL-compatible video. The term subtitle has been replaced with caption in a number of markets—such as Australia and New Zealand—that purchase large amounts of imported US material, with much of that video having had the US CC logo already superimposed over the start of it. In New Zealand, broadcasters superimpose an ear logo with a line through it that represents subtitles for the hard of hearing, even though they are currently referred to as captions. In the UK, modern digital television services have subtitles for the majority of programs, so it is no longer necessary to highlight which have subtitling/captioning and which do not. ", "section_idx": 1, "section_name": "Terminology", "target_page_ids": [ 31717, 14560, 1926240, 175642 ], "anchor_spans": [ [ 4, 18 ], [ 20, 27 ], [ 418, 427 ], [ 511, 517 ] ] }, { "plaintext": "Remote control handsets for TVs, DVDs, and similar devices in most European markets often use \"SUB\" or \"SUBTITLE\" on the button used to control the display of subtitles/captions.", "section_idx": 1, "section_name": "Terminology", "target_page_ids": [ 105803 ], "anchor_spans": [ [ 0, 14 ] ] }, { "plaintext": "Regular open-captioned broadcasts began on PBS's The French Chef in 1972. WGBH began open captioning of the programs Zoom, ABC World News Tonight, and Once Upon a Classic shortly thereafter.", "section_idx": 2, "section_name": "History", "target_page_ids": [ 29697498, 913305, 484826, 247609, 194731, 26173804 ], "anchor_spans": [ [ 43, 46 ], [ 49, 64 ], [ 74, 78 ], [ 117, 121 ], [ 123, 145 ], [ 151, 170 ] ] }, { "plaintext": "Closed captioning was first demonstrated in the United States at the First National Conference on Television for the Hearing Impaired in Nashville, Tennessee, in 1971. A second demonstration of closed captioning was held at Gallaudet College (now Gallaudet University) on February 15, 1972, where ABC and the National Bureau of Standards demonstrated closed captions embedded within a normal broadcast of The Mod Squad.", "section_idx": 2, "section_name": "History", "target_page_ids": [ 184191, 62027, 21888, 555720 ], "anchor_spans": [ [ 247, 267 ], [ 297, 300 ], [ 309, 337 ], [ 405, 418 ] ] }, { "plaintext": "At the same time in the UK the BBC was demonstrating its Ceefax text based broadcast service which they were already using as a foundation to the development of a closed caption production system. They were working with Professor Alan Newell from the University of Southampton who had been developing prototypes in the late 1960s.", "section_idx": 2, "section_name": "History", "target_page_ids": [ 57038283 ], "anchor_spans": [ [ 230, 241 ] ] }, { "plaintext": "The closed captioning system was successfully encoded and broadcast in 1973 with the cooperation of PBS station WETA. As a result of these tests, the FCC in 1976 set aside line 21 for the transmission of closed captions. PBS engineers then developed the caption editing consoles that would be used to caption prerecorded programs.", "section_idx": 2, "section_name": "History", "target_page_ids": [ 1753836 ], "anchor_spans": [ [ 112, 116 ] ] }, { "plaintext": "The BBC in the UK was the first broadcaster to include closed captions (called subtitles in the UK) in 1979 based on the Teletext framework for pre-recorded programming.", "section_idx": 2, "section_name": "History", "target_page_ids": [ 19344654, 1926240 ], "anchor_spans": [ [ 4, 7 ], [ 121, 129 ] ] }, { "plaintext": "Real-time captioning, a process for captioning live broadcasts, was developed by the National Captioning Institute in 1982. In real-time captioning, stenotype operators who are able to type at speeds of over 225 words per minute provide captions for live television programs, allowing the viewer to see the captions within two to three seconds of the words being spoken.", "section_idx": 2, "section_name": "History", "target_page_ids": [ 5247207, 513332 ], "anchor_spans": [ [ 85, 114 ], [ 149, 158 ] ] }, { "plaintext": "Major US producers of captions are WGBH-TV, VITAC, CaptionMax and the National Captioning Institute. In the UK and Australasia, Ai-Media, Red Bee Media, itfc, and Independent Media Support are the major vendors.", "section_idx": 2, "section_name": "History", "target_page_ids": [ 484826, 16215542, 5506012, 5247207, 21492915, 21967345 ], "anchor_spans": [ [ 35, 42 ], [ 44, 49 ], [ 51, 61 ], [ 70, 99 ], [ 115, 126 ], [ 138, 151 ] ] }, { "plaintext": "Improvements in speech recognition technology means that live captioning may be fully or partially automated. BBC Sport broadcasts use a \"respeaker\": a trained human who repeats the running commentary (with careful enunciation and some simplification and markup) for input to the automated text generation system. This is generally reliable, though errors are not unknown.", "section_idx": 2, "section_name": "History", "target_page_ids": [ 29468, 3095179, 18910 ], "anchor_spans": [ [ 16, 34 ], [ 110, 119 ], [ 255, 261 ] ] }, { "plaintext": "The National Captioning Institute was created in 1979 in order to get the cooperation of the commercial television networks.", "section_idx": 2, "section_name": "History", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The first use of regularly scheduled closed captioning on American television occurred on March 16, 1980. Sears had developed and sold the Telecaption adapter, a decoding unit that could be connected to a standard television set. The first programs seen with captioning were a Disney's Wonderful World presentation of the film Son of Flubber on NBC, an ABC Sunday Night Movie airing of Semi-Tough, and Masterpiece Theatre on PBS.", "section_idx": 2, "section_name": "History", "target_page_ids": [ 277858, 357520, 8343583, 21780, 1020586, 381006, 154796, 29697498 ], "anchor_spans": [ [ 106, 111 ], [ 277, 301 ], [ 327, 341 ], [ 345, 348 ], [ 353, 375 ], [ 386, 396 ], [ 402, 421 ], [ 425, 428 ] ] }, { "plaintext": "Since 2010 BBC provides a 100% broadcast captioning service across all 7 of its main broadcast channels BBC One, BBC Two, BBC Three, BBC Four, CBBC, Cbeebies and BBC News (TV channel).", "section_idx": 2, "section_name": "History", "target_page_ids": [ 212157, 160949, 393289, 345439, 18952437, 393295, 4621 ], "anchor_spans": [ [ 104, 111 ], [ 113, 120 ], [ 122, 131 ], [ 133, 141 ], [ 143, 147 ], [ 149, 157 ], [ 162, 183 ] ] }, { "plaintext": "BBC iPlayer launched in 2008 as the first captioned Video on demand service from a major broadcaster meeting comparable levels of captioning as those provided on its broadcast channels.", "section_idx": 2, "section_name": "History", "target_page_ids": [ 2508745, 147143 ], "anchor_spans": [ [ 0, 11 ], [ 52, 67 ] ] }, { "plaintext": "Until the passage of the Television Decoder Circuitry Act of 1990, television captioning was performed by a set-top box manufactured by Sanyo Electric and marketed by the National Captioning Institute (NCI). (At that time a set-top decoder cost about as much as a TV set itself, approximately $200.) Through discussions with the manufacturer it was established that the appropriate circuitry integrated into the television set would be less expensive than the stand-alone box, and Ronald May, then a Sanyo employee, provided the expert witness testimony on behalf of Sanyo and Gallaudet University in support of the passage of the bill. On January 23, 1991, the Television Decoder Circuitry Act of 1990 was passed by Congress. This Act gave the Federal Communications Commission (FCC) power to enact rules on the implementation of closed captioning. This Act required all analog television receivers with screens of at least 13inches or greater, either sold or manufactured, to have the ability to display closed captioning by July 1, 1993.", "section_idx": 2, "section_name": "History", "target_page_ids": [ 55974 ], "anchor_spans": [ [ 745, 778 ] ] }, { "plaintext": "Also, in 1990, the Americans with Disabilities Act (ADA) was passed to ensure equal opportunity for persons with disabilities. The ADA prohibits discrimination against persons with disabilities in public accommodations or commercial facilities. Title III of the ADA requires that public facilities—such as hospitals, bars, shopping centers and museums (but not movie theaters)—provide access to verbal information on televisions, films or slide shows.", "section_idx": 2, "section_name": "History", "target_page_ids": [ 1338 ], "anchor_spans": [ [ 19, 50 ] ] }, { "plaintext": "The Federal Communications Commission requires all providers of programs to caption material which has audio in English or Spanish, with certain exceptions specified in Section 79.1(d) of the commission's rules. These exceptions apply to new networks; programs in languages other than English or Spanish; networks having to spend over 2% of income on captioning; networks having less than US$3,000,000 in revenue; and certain local programs; among other exceptions. Those who are not covered by the exceptions may apply for a hardship waiver.", "section_idx": 2, "section_name": "History", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The Telecommunications Act of 1996 expanded on the Decoder Circuitry Act to place the same requirements on digital television receivers by July 1, 2002. All TV programming distributors in the U.S. are required to provide closed captions for Spanish-language video programming as of January 1, 2010.", "section_idx": 2, "section_name": "History", "target_page_ids": [ 196010, 8271 ], "anchor_spans": [ [ 4, 34 ], [ 107, 125 ] ] }, { "plaintext": "A bill, H.R. 3101, the Twenty-First Century Communications and Video Accessibility Act of 2010, was passed by the United States House of Representatives in July 2010. A similar bill, S. 3304, with the same name, was passed by the United States Senate on August 5, 2010, by the House of Representatives on September 28, 2010, and was signed by President Barack Obama on October 8, 2010. The Act requires, in part, for ATSC-decoding set-top box remotes to have a button to turn on or off the closed captioning in the output signal. It also requires broadcasters to provide captioning for television programs redistributed on the Internet.", "section_idx": 2, "section_name": "History", "target_page_ids": [ 534366, 272313 ], "anchor_spans": [ [ 353, 365 ], [ 417, 421 ] ] }, { "plaintext": "On February 20, 2014, the FCC unanimously approved the implementation of quality standards for closed captioning, addressing accuracy, timing, completeness, and placement. This is the first time the FCC has addressed quality issues in captions.", "section_idx": 2, "section_name": "History", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "In 2015, a law was passed in Hawaii requiring two screenings a week of each movie with captions on the screen. In 2022 a law took effect in New York City requiring movie theaters to offer captions on the screen for up to four showtimes per movie each week, including weekends and Friday nights.", "section_idx": 2, "section_name": "History", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "As amended by RA 10905, all TV networks in the Philippines are required to give CC. As of 2018, the three major TV networks in the country are currently testing the closed captioning system on their transmissions. ABS-CBN added CC in their daily 3 O'Clock Habit in the afternoon. 5 started implementing CCs on their live noon and nightly news programs. GMA was once started broadcasting nightly and late night news programs, but then they stopped adding CCs lately. Only select Korean drama and local or foreign movies, Biyahe ni Drew (English: Drew's Explorations) and Idol sa Kusina (English: Kitchen Idol) are the programs and shows that they air with proper closed captioning.", "section_idx": 2, "section_name": "History", "target_page_ids": [ 2503405, 2046741, 2713787, 2198623, 2327048 ], "anchor_spans": [ [ 214, 221 ], [ 246, 261 ], [ 280, 281 ], [ 353, 356 ], [ 478, 490 ] ] }, { "plaintext": "Closed captioning in some Filipino films either to be \"included\" if film production companies have a bias on having impact on their viewing experience for those who did not understand the language. Since 2016, all Filipino-Language Films and also on some Streaming Services like iWant had included their English Subtitles in some showing on films. The law regarding that was passed by Gerald Anthony Gullas Jr., a lawmaker from Cebu City, who had implemented the regulations on standardizing both official languages of the Philippines, as the people had not fluently mastered their English vocabulary.", "section_idx": 2, "section_name": "History", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The government of Australia provided seed funding in 1981 for the establishment of the Australian Caption Centre (ACC) and the purchase of equipment. Captioning by the ACC commenced in 1982 and a further grant from the Australian government enabled the ACC to achieve and maintain financial self-sufficiency. The ACC, now known as Media Access Australia, sold its commercial captioning division to Red Bee Media in December 2005. Red Bee Media continues to provide captioning services in Australia today.", "section_idx": 2, "section_name": "History", "target_page_ids": [ 484731, 18122348, 21967345 ], "anchor_spans": [ [ 37, 49 ], [ 331, 353 ], [ 398, 411 ] ] }, { "plaintext": "In 1981, TVNZ held a telethon to raise funds for Teletext-encoding equipment used for the creation and editing of text-based broadcast services for the deaf. The service came into use in 1984 with caption creation and importing paid for as part of the public broadcasting fee until the creation of the NZ on Air taxpayer fund, which is used to provide captioning for NZ On Air content, TVNZ news shows and conversion of EIA-608 US captions to the preferred EBU STL format for only TVNZ 1, TV 2 and TV 3 with archived captions available to FOUR and select Sky programming. During the second half of 2012, TV3 and FOUR began providing non-Teletext DVB image-based captions on their HD service and used the same format on the satellite service, which has since caused major timing issues in relation to server load and the loss of captions from most SD DVB-S receivers, such as the ones Sky Television provides their customers. As of April 2, 2013, only the Teletext page 801 caption service will remain in use with the informational Teletext non-caption content being discontinued.", "section_idx": 2, "section_name": "History", "target_page_ids": [ 369460, 301917, 5024049, 5024049, 1154851, 10380, 3708400, 4538977, 607291, 30043629, 575577, 607291, 30043629 ], "anchor_spans": [ [ 9, 13 ], [ 21, 29 ], [ 302, 311 ], [ 367, 376 ], [ 420, 427 ], [ 457, 460 ], [ 481, 487 ], [ 489, 493 ], [ 498, 502 ], [ 539, 543 ], [ 555, 558 ], [ 604, 607 ], [ 612, 616 ] ] }, { "plaintext": "Closed captions were created for deaf and hard of hearing individuals to assist in comprehension. They can also be used as a tool by those learning to read, learning to speak a non-native language, or in an environment where the audio is difficult to hear or is intentionally muted. Captions can also be used by viewers who simply wish to read a transcript along with the program audio.", "section_idx": 3, "section_name": "Application", "target_page_ids": [ 42029762, 49604 ], "anchor_spans": [ [ 33, 37 ], [ 42, 57 ] ] }, { "plaintext": "In the United States, the National Captioning Institute noted that English as a foreign or second language (ESL) learners were the largest group buying decoders in the late 1980s and early 1990s before built-in decoders became a standard feature of US television sets. This suggested that the largest audience of closed captioning was people whose native language was not English. In the United Kingdom, of 7.5 million people using TV subtitles (closed captioning), 6 million have no hearing impairment.", "section_idx": 3, "section_name": "Application", "target_page_ids": [ 5247207, 415406 ], "anchor_spans": [ [ 26, 55 ], [ 67, 106 ] ] }, { "plaintext": "Closed captions are also used in public environments, such as bars and restaurants, where patrons may not be able to hear over the background noise, or where multiple televisions are displaying different programs. In addition, online videos may be treated through digital processing of their audio content by various robotic algorithms (robots). Multiple chains of errors are the result. When a video is truly and accurately transcribed, then the closed-captioning publication serves a useful purpose, and the content is available for search engines to index and make available to users on the internet.", "section_idx": 3, "section_name": "Application", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Some television sets can be set to automatically turn captioning on when the volume is muted.", "section_idx": 3, "section_name": "Application", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "For live programs, spoken words comprising the television program's soundtrack are transcribed by a human operator (a speech-to-text reporter) using stenotype or stenomask type of machines, whose phonetic output is instantly translated into text by a computer and displayed on the screen. This technique was developed in the 1970s as an initiative of the BBC's Ceefax teletext service. In collaboration with the BBC, a university student took on the research project of writing the first phonetics-to-text conversion program for this purpose. Sometimes, the captions of live broadcasts, like news bulletins, sports events, live entertainment shows, and other live shows, fall behind by a few seconds. This delay is because the machine does not know what the person is going to say next, so after the person on the show says the sentence, the captions appear. Automatic computer speech recognition works well when trained to recognize a single voice, and so since 2003, the BBC does live subtitling by having someone re-speak what is being broadcast. Live captioning is also a form of real-time text. Meanwhile, sport events on ESPN are using court reporters, using a special (steno) keyboard and individually constructed \"dictionaries.\"", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 46621, 12689044, 513332, 462594, 19344654, 175642, 1926240, 32335474, 305384 ], "anchor_spans": [ [ 68, 78 ], [ 118, 141 ], [ 149, 158 ], [ 162, 171 ], [ 355, 358 ], [ 361, 367 ], [ 368, 376 ], [ 1084, 1098 ], [ 1142, 1156 ] ] }, { "plaintext": "In some cases, the transcript is available beforehand, and captions are simply displayed during the program after being edited. For programs that have a mix of pre-prepared and live content, such as news bulletins, a combination of techniques is used.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 1449800 ], "anchor_spans": [ [ 199, 212 ] ] }, { "plaintext": "For prerecorded programs, commercials, and home videos, audio is transcribed and captions are prepared, positioned, and timed in advance.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "For all types of NTSC programming, captions are \"encoded\" into line 21 of the vertical blanking interval - a part of the TV picture that sits just above the visible portion and is usually unseen. For ATSC (digital television) programming, three streams are encoded in the video: two are backward compatible \"line 21\" captions, and the third is a set of up to 63 additional caption streams encoded in EIA-708 format.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 21689, 1154851, 329829, 272313, 8271, 1149687 ], "anchor_spans": [ [ 17, 21 ], [ 63, 70 ], [ 78, 104 ], [ 200, 204 ], [ 206, 224 ], [ 400, 407 ] ] }, { "plaintext": "Captioning is modulated and stored differently in PAL and SECAM 625 line 25 frame countries, where teletext is used rather than in EIA-608, but the methods of preparation and the line 21 field used are similar. For home Betamax and VHS videotapes, a shift down of this line 21 field must be done due to the greater number of VBI lines used in 625 line PAL countries, though only a small minority of European PAL VHS machines support this (or any) format for closed caption recording. Like all teletext fields, teletext captions can't be stored by a standard 625 line VHS recorder (due to the lack of field shifting support); they are available on all professional S-VHS recordings due to all fields being recorded. Recorded Teletext caption fields also suffer from a higher number of caption errors due to increased number of bits and a low SNR, especially on low-bandwidth VHS. This is why Teletext captions used to be stored separately on floppy disk to the analogue master tape. DVDs have their own system for subtitles and captions, which are digitally inserted in the data stream and decoded on playback into video.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 24438, 28706, 1926240, 1154851, 188578, 52124, 159598, 41706 ], "anchor_spans": [ [ 50, 53 ], [ 58, 63 ], [ 99, 107 ], [ 131, 138 ], [ 220, 227 ], [ 232, 235 ], [ 664, 669 ], [ 841, 844 ] ] }, { "plaintext": "For older televisions, a set-top box or other decoder is usually required. In the US, since the passage of the Television Decoder Circuitry Act, manufacturers of most television receivers sold have been required to include closed captioning display capability. High-definition TV sets, receivers, and tuner cards are also covered, though the technical specifications are different (high-definition display screens, as opposed to high-definition TVs, may lack captioning). Canada has no similar law but receives the same sets as the US in most cases.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 626814 ], "anchor_spans": [ [ 301, 312 ] ] }, { "plaintext": "During transmission, single byte errors can be replaced by a white space which can appear at the beginning of the program. More byte errors during EIA-608 transmission can affect the screen momentarily, by defaulting to a real-time mode such as the \"roll up\" style, type random letters on screen, and then revert to normal. Uncorrectable byte errors within the teletext page header will cause whole captions to be dropped. EIA-608, due to using only two characters per video frame, sends these captions ahead of time storing them in a second buffer awaiting a command to display them; Teletext sends these in real-time.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The use of capitalization varies among caption providers. Most caption providers capitalize all words while others such as WGBH and non-US providers prefer to use mixed-case letters.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "There are two main styles of line 21 closed captioning:", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Roll-up or scroll-up or paint-on or scrolling: Real-time words sent in paint-on or scrolling mode appear from left to right, up to one line at a time; when a line is filled in roll-up mode, the whole line scrolls up to make way for a new line, and the line on top is erased. The lines usually appear at the bottom of the screen, but can actually be placed on any of the 14 screen rows to avoid covering graphics or action. This method is used when captioning video in real-time such as for live events, where a sequential word-by-word captioning process is needed or a pre-made intermediary file isn't available. This method is signaled on EIA-608 by a two-byte caption command or in Teletext by replacing rows for a roll-up effect and duplicating rows for a paint-on effect. This allows for real-time caption line editing.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 1154851 ], "anchor_spans": [ [ 641, 648 ] ] }, { "plaintext": " Pop-on or pop-up or block: A caption appears on any of the 14 screen rows as a complete sentence, which can be followed by additional captions. This method is used when captions come from an intermediary file (such as the Scenarist or EBU STL file formats) for pre-taped television and film programming, commonly produced at captioning facilities. This method of captioning can be aided by digital scripts or voice recognition software, and if used for live events, would require a video delay to avoid a large delay in the captions' appearance on-screen, which occurs with Teletext-encoded live subtitles.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "TVNZ Access Services and Red Bee Media for BBC and Australia example:", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 369460 ], "anchor_spans": [ [ 0, 4 ] ] }, { "plaintext": "UK IMS for ITV and Sky example:", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "US WGBH Access Services example:", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "US National Captioning Institute example:", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 5247207 ], "anchor_spans": [ [ 3, 32 ] ] }, { "plaintext": "US other provider example:", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "US in-house real-time roll-up example:", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Non-US in-house real-time roll-up example:", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "US CaptionMax example:", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 5506012 ], "anchor_spans": [ [ 3, 13 ] ] }, { "plaintext": "For real-time captioning done outside of captioning facilities, the following syntax is used:", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " '>>' (two prefixed greater-than signs) indicates a change in single speaker.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 11033536 ], "anchor_spans": [ [ 20, 37 ] ] }, { "plaintext": " Sometimes appended with the speaker's name in alternate case, followed by a colon.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 59131 ], "anchor_spans": [ [ 77, 82 ] ] }, { "plaintext": " '>>>' (three prefixed greater-than signs) indicates a change in news story or multiple speakers.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Styles of syntax that are used by various captioning producers:", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Capitals indicate main on-screen dialogue and the name of the speaker.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Legacy EIA-608 home caption decoder fonts had no descenders on lowercase letters.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 1154851, 935991 ], "anchor_spans": [ [ 8, 15 ], [ 50, 59 ] ] }, { "plaintext": " Outside North America, capitals with background coloration indicate a song title or sound effect description.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Outside North America, capitals with black or no background coloration indicates when a word is stressed or emphasized.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Descenders indicate background sound description and off-screen dialogue.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 61218080 ], "anchor_spans": [ [ 54, 64 ] ] }, { "plaintext": " Most modern caption producers, such as WGBH-TV, use mixed case for both on-screen and off-screen dialogue.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 484826, 215741, 61218080 ], "anchor_spans": [ [ 40, 47 ], [ 53, 63 ], [ 87, 97 ] ] }, { "plaintext": " '-' (a prefixed dash) indicates a change in single speaker (used by CaptionMax).", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 5506012 ], "anchor_spans": [ [ 69, 79 ] ] }, { "plaintext": " Words in italics indicate when a word is stressed or emphasized and when real world names are quoted.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 265914 ], "anchor_spans": [ [ 10, 17 ] ] }, { "plaintext": " Italics and bold type are only supported by EIA-608.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 219805, 1154851 ], "anchor_spans": [ [ 13, 22 ], [ 45, 52 ] ] }, { "plaintext": " Some North American providers use this for narrated dialogue.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 565176 ], "anchor_spans": [ [ 44, 52 ] ] }, { "plaintext": " Some providers use this for off-screen dialogue.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 61218080 ], "anchor_spans": [ [ 29, 39 ] ] }, { "plaintext": " Italics are also applied when a word is spoken in a foreign language.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Text coloration indicates captioning credits and sponsorship.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Used by music videos in the past, but generally has declined due to system incompatibilities.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 90138 ], "anchor_spans": [ [ 9, 20 ] ] }, { "plaintext": " In Ceefax/Teletext countries, it indicates a change in single speaker in place of '>>'.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Some Teletext countries use coloration to indicate when a word is stressed or emphasized.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Coloration is limited to white, green, blue, cyan, red, yellow and magenta.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " UK order of use for text is white, green, cyan, yellow; and backgrounds is black, red, blue, magenta, white.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 17599355, 12460, 6102, 34368, 4035, 25825, 4543, 46408, 17599355 ], "anchor_spans": [ [ 29, 34 ], [ 36, 41 ], [ 43, 47 ], [ 49, 55 ], [ 76, 81 ], [ 83, 86 ], [ 88, 92 ], [ 94, 101 ], [ 103, 108 ] ] }, { "plaintext": " US order of use for text is white, yellow, cyan, green; and backgrounds is black, blue, red, magenta, white.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 17599355, 34368, 6102, 12460, 4035, 4543, 25825, 46408 ], "anchor_spans": [ [ 29, 34 ], [ 36, 42 ], [ 44, 48 ], [ 50, 55 ], [ 76, 81 ], [ 83, 87 ], [ 89, 92 ], [ 94, 101 ] ] }, { "plaintext": " Square brackets or parentheses indicate a song title or sound effect description.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 59338, 59338 ], "anchor_spans": [ [ 1, 16 ], [ 20, 31 ] ] }, { "plaintext": " Parentheses indicate speaker's vocal pitch e.g., (man), (woman), (boy) or (girl).", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 59338 ], "anchor_spans": [ [ 1, 12 ] ] }, { "plaintext": " Outside North America, parentheses indicate a silent on-screen action.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 59338 ], "anchor_spans": [ [ 24, 35 ] ] }, { "plaintext": " A pair of eighth notes is used to bracket a line of lyrics to indicate singing.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 88706, 38518 ], "anchor_spans": [ [ 11, 22 ], [ 53, 59 ] ] }, { "plaintext": " A pair of eighth notes on a line of no text are used during a section of instrumental music.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Outside North America, a single number sign is used on a line of lyrics to indicate singing.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 59006, 38518 ], "anchor_spans": [ [ 33, 44 ], [ 66, 72 ] ] }, { "plaintext": " An additional musical notation character is appended to the end of the last line of lyrics to indicate the song's end.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " As the symbol is unsupported by Ceefax/Teletext, a number sign - which resembles a musical sharp - is substituted.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 175642, 1926240, 59006, 139920 ], "anchor_spans": [ [ 33, 39 ], [ 40, 48 ], [ 52, 63 ], [ 92, 97 ] ] }, { "plaintext": "There were many shortcomings in the original Line 21 specification from a typographic standpoint, since, for example, it lacked many of the characters required for captioning in languages other than English. Since that time, the core Line 21 character set has been expanded to include quite a few more characters, handling most requirements for languages common in North and South America such as French, Spanish, and Portuguese, though those extended characters are not required in all decoders and are thus unreliable in everyday use. The problem has been almost eliminated with a market specific full set of Western European characters and a private adopted Norpak extension for South Korean and Japanese markets. The full EIA-708 standard for digital television has worldwide character set support, but there has been little use of it due to EBU Teletext dominating DVB countries, which has its own extended character sets.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 31217, 10597, 26825, 23915, 3614445, 27019, 15573, 1149687, 10380, 146977 ], "anchor_spans": [ [ 74, 85 ], [ 397, 403 ], [ 405, 412 ], [ 418, 428 ], [ 661, 667 ], [ 682, 694 ], [ 699, 707 ], [ 726, 733 ], [ 846, 849 ], [ 870, 873 ] ] }, { "plaintext": "Captions are often edited to make them easier to read and to reduce the amount of text displayed onscreen. This editing can be very minor, with only a few occasional unimportant missed lines, to severe, where virtually every line spoken by the actors is condensed. The measure used to guide this editing is words per minute, commonly varying from 180 to 300, depending on the type of program. Offensive words are also captioned, but if the program is censored for TV broadcast, the broadcaster might not have arranged for the captioning to be edited or censored also. The \"TV Guardian\", a television set-top box, is available to parents who wish to censor offensive language of programs—the video signal is fed into the box and if it detects an offensive word in the captioning, the audio signal is bleeped or muted for that period of time.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 29580 ], "anchor_spans": [ [ 600, 611 ] ] }, { "plaintext": "The Line 21 data stream can consist of data from several data channels multiplexed together. Odd field 1 can have four data channels: two separate synchronized captions (CC1, CC2) with caption-related text, such as website URLs (T1, T2). Even field 2 can have five additional data channels: two separate synchronized captions (CC3, CC4) with caption related text (T3, T4), and Extended Data Services (XDS) for Now/Next EPG details. XDS data structure is defined in CEA-608.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 41389, 47817022, 1907548, 1331154 ], "anchor_spans": [ [ 71, 82 ], [ 223, 226 ], [ 377, 399 ], [ 419, 422 ] ] }, { "plaintext": "As CC1 and CC2 share bandwidth, if there is a lot of data in CC1, there will be little room for CC2 data and is generally only used for the primary audio captions. Similarly, CC3 and CC4 share the second even field of line 21. Since some early caption decoders supported only single field decoding of CC1 and CC2, captions for SAP in a second language were often placed in CC2. This led to bandwidth problems, and the U.S. Federal Communications Commission (FCC) recommendation is that bilingual programming should have the second caption language in CC3. Many Spanish television networks such as Univision and Telemundo, for example, provides English subtitles for many of its Spanish programs in CC3. Canadian broadcasters use CC3 for French translated SAPs, which is also a similar practice in South Korea and Japan.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 276779, 55974, 16118202, 10839777, 10839777, 26667, 5042916 ], "anchor_spans": [ [ 327, 330 ], [ 423, 456 ], [ 597, 606 ], [ 611, 620 ], [ 644, 661 ], [ 678, 685 ], [ 703, 711 ] ] }, { "plaintext": "Ceefax and Teletext can have a larger number of captions for other languages due to the use of multiple VBI lines. However, only European countries used a second subtitle page for second language audio tracks where either the NICAM dual mono or Zweikanalton were used.", "section_idx": 4, "section_name": "Television and video", "target_page_ids": [ 9239, 501983, 3666628 ], "anchor_spans": [ [ 129, 147 ], [ 226, 231 ], [ 245, 257 ] ] }, { "plaintext": "The US ATSC digital television system originally specified two different kinds of closed captioning datastream standards: the original analog-compatible (available by Line 21) and the more modern digital-only CEA-708 formats are delivered within the video stream. The US FCC mandates that broadcasters deliver (and generate, if necessary) both datastream formats with the CEA-708 format merely a conversion of the Line 21 format. The Canadian CRTC has not mandated that broadcasters either broadcast both datastream formats or exclusively in one format. Most broadcasters and networks to avoid large conversion cost outlays just provide EIA-608 captions along with a transcoded CEA-708 version encapsulated within CEA-708 packets.", "section_idx": 5, "section_name": "Digital television interoperability issues", "target_page_ids": [ 272313, 8271, 1154851, 1149687, 55974, 1149687, 5042916, 5985, 1154851, 1149687, 1149687 ], "anchor_spans": [ [ 7, 11 ], [ 12, 30 ], [ 167, 174 ], [ 209, 216 ], [ 268, 274 ], [ 372, 379 ], [ 434, 442 ], [ 443, 447 ], [ 637, 644 ], [ 678, 685 ], [ 714, 721 ] ] }, { "plaintext": "Many viewers find that when they acquire a digital television or set-top box they are unable to view closed caption (CC) information, even though the broadcaster is sending it and the TV is able to display it.", "section_idx": 5, "section_name": "Digital television interoperability issues", "target_page_ids": [ 8271, 29580, 29831 ], "anchor_spans": [ [ 43, 61 ], [ 65, 76 ], [ 184, 186 ] ] }, { "plaintext": "Originally, CC information was included in the picture (\"line 21\") via a composite video input, but there is no equivalent capability in digital video interconnects (such as DVI and HDMI) between the display and a \"source\". A \"source\", in this case, can be a DVD player or a terrestrial or cable digital television receiver. When CC information is encoded in the MPEG-2 data stream, only the device that decodes the MPEG-2 data (a source) has access to the closed caption information; there is no standard for transmitting the CC information to a display monitor separately. Thus, if there is CC information, the source device needs to overlay the CC information on the picture prior to transmitting to the display over the interconnect's video output.", "section_idx": 5, "section_name": "Digital television interoperability issues", "target_page_ids": [ 149902, 60980, 537442, 172809, 231064, 20060, 20060 ], "anchor_spans": [ [ 73, 94 ], [ 174, 177 ], [ 182, 186 ], [ 259, 269 ], [ 275, 286 ], [ 363, 369 ], [ 416, 427 ] ] }, { "plaintext": "The responsibility of decoding the CC information and overlaying onto the visible video image has been taken away from the TV display and put into the \"source\" of DVI and HDMI digital video interconnects. Because the TV handles \"mute\" and, when using DVI and HDMI, a different device handles turning on and off CC, this means the \"captions come on automatically when the TV is muted\" feature no longer works. That source device—such as a DVD player or set-top box—must \"burn\" the image of the CC text into the picture data carried by the HDMI or DVI cable; there's no other way for the CC text to be carried over the HDMI or DVI cable.", "section_idx": 5, "section_name": "Digital television interoperability issues", "target_page_ids": [ 60980, 537442, 29831, 172809, 29580, 537442, 60980, 537442, 60980 ], "anchor_spans": [ [ 251, 254 ], [ 259, 263 ], [ 371, 373 ], [ 438, 448 ], [ 452, 463 ], [ 538, 542 ], [ 546, 549 ], [ 617, 621 ], [ 625, 628 ] ] }, { "plaintext": "Many source devices do not have the ability to overlay CC information, for controlling the CC overlay can be complicated. For example, the Motorola DCT-5xxx and -6xxx cable set-top receivers have the ability to decode CC information located on the MPEG-2 stream and overlay it on the picture, but turning CC on and off requires turning off the unit and going into a special setup menu (it is not on the standard configuration menu and it cannot be controlled using the remote). Historically, DVD players, VCRs and set-top tuners did not need to do this overlaying, since they simply passed this information on to the TV, and they are not mandated to perform this overlaying.", "section_idx": 5, "section_name": "Digital television interoperability issues", "target_page_ids": [ 20319, 20060, 172809, 23442715 ], "anchor_spans": [ [ 139, 147 ], [ 248, 254 ], [ 492, 503 ], [ 505, 509 ] ] }, { "plaintext": "Many modern digital television receivers can be directly connected to cables, but often cannot receive scrambled channels that the user is paying for. Thus, the lack of a standard way of sending CC information between components, along with the lack of a mandate to add this information to a picture, results in CC being unavailable to many hard-of-hearing and deaf users.", "section_idx": 5, "section_name": "Digital television interoperability issues", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The EBU Ceefax-based teletext systems are the source for closed captioning signals, thus when teletext is embedded into DVB-T or DVB-S the closed captioning signal is included. However, for DVB-T and DVB-S, it is not necessary for a teletext page signal to also be present (ITV1, for example, does not carry analogue teletext signals on Sky Digital, but does carry the embedded version, accessible from the \"Services\" menu of the receiver, or more recently by turning them off/on from a mini menu accessible from the \"help\" button).", "section_idx": 5, "section_name": "Digital television interoperability issues", "target_page_ids": [ 10380, 175642, 262796, 262794, 212177, 321943 ], "anchor_spans": [ [ 4, 7 ], [ 8, 14 ], [ 120, 125 ], [ 129, 134 ], [ 274, 278 ], [ 337, 348 ] ] }, { "plaintext": "The BBC's Subtitle (Captioning) Editorial Guidelines were born out of the capabilities of Teletext but are now used by multiple European broadcasters as the editorial and design best practice guide ", "section_idx": 5, "section_name": "Digital television interoperability issues", "target_page_ids": [ 19344654, 1926240 ], "anchor_spans": [ [ 4, 9 ], [ 90, 98 ] ] }, { "plaintext": "In New Zealand, captions use an EBU Ceefax-based teletext system on DVB broadcasts via satellite and cable television with the exception of MediaWorks New Zealand channels who completely switched to DVB RLE subtitles in 2012 on both Freeview satellite and UHF broadcasts, this decision was made based on the TVNZ practice of using this format on only DVB UHF broadcasts (aka Freeview HD). This made composite video connected TVs incapable of decoding the captions on their own. Also, these pre-rendered subtitles use classic caption style opaque backgrounds with an overly large font size and obscure the picture more than the more modern, partially transparent backgrounds.", "section_idx": 5, "section_name": "Digital television interoperability issues", "target_page_ids": [ 10380, 175642, 146977, 7527410, 7587, 27768260, 262796, 26392, 146606, 160501, 369460, 146977, 160501, 146606, 149902, 3157091, 991349 ], "anchor_spans": [ [ 32, 35 ], [ 36, 42 ], [ 68, 71 ], [ 87, 96 ], [ 101, 117 ], [ 140, 162 ], [ 199, 202 ], [ 203, 206 ], [ 233, 241 ], [ 256, 259 ], [ 308, 312 ], [ 351, 354 ], [ 355, 358 ], [ 375, 386 ], [ 399, 414 ], [ 490, 502 ], [ 579, 588 ] ] }, { "plaintext": "The CEA-708 specification provides for dramatically improved captioning", "section_idx": 5, "section_name": "Digital television interoperability issues", "target_page_ids": [ 1149687 ], "anchor_spans": [ [ 4, 11 ] ] }, { "plaintext": " An enhanced character set with more accented letters and non-Latin letters, and more special symbols", "section_idx": 5, "section_name": "Digital television interoperability issues", "target_page_ids": [ 8439 ], "anchor_spans": [ [ 37, 53 ] ] }, { "plaintext": " Viewer-adjustable text size (called the \"caption volume control\" in the specification), allowing individuals to adjust their TVs to display small, normal, or large captions", "section_idx": 5, "section_name": "Digital television interoperability issues", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " More text and background colors, including both transparent and translucent backgrounds to optionally replace the big black block", "section_idx": 5, "section_name": "Digital television interoperability issues", "target_page_ids": [ 4035 ], "anchor_spans": [ [ 119, 124 ] ] }, { "plaintext": " More text styles, including edged or drop shadowed text rather than the letters on a solid background", "section_idx": 5, "section_name": "Digital television interoperability issues", "target_page_ids": [ 3668374 ], "anchor_spans": [ [ 38, 49 ] ] }, { "plaintext": " More text fonts, including monospaced and proportional spaced, serif and sans-serif, and some playful cursive fonts", "section_idx": 5, "section_name": "Digital television interoperability issues", "target_page_ids": [ 53501, 64100, 64097 ], "anchor_spans": [ [ 28, 38 ], [ 64, 69 ], [ 74, 84 ] ] }, { "plaintext": " Higher bandwidth, to allow more data per minute of video", "section_idx": 5, "section_name": "Digital television interoperability issues", "target_page_ids": [ 15612827, 18985040, 32441 ], "anchor_spans": [ [ 8, 17 ], [ 33, 37 ], [ 52, 57 ] ] }, { "plaintext": " More language channels, to allow the encoding of more independent caption streams", "section_idx": 5, "section_name": "Digital television interoperability issues", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "As of 2009, most closed captioning for digital television environments is done using tools designed for analog captioning (working to the CEA-608 NTSC specification rather than the CEA-708 ATSC specification). The captions are then run through transcoders made by companies like EEG Enterprises or Evertz, which convert the analog Line 21 caption format to the digital format. This means that none of the CEA-708 features are used unless they were also contained in CEA-608.", "section_idx": 5, "section_name": "Digital television interoperability issues", "target_page_ids": [ 1154851, 21689, 1149687, 272313, 32468562, 1154851, 1149687, 1154851 ], "anchor_spans": [ [ 138, 145 ], [ 146, 150 ], [ 181, 188 ], [ 189, 193 ], [ 298, 304 ], [ 331, 353 ], [ 405, 412 ], [ 466, 473 ] ] }, { "plaintext": "NTSC DVDs may carry closed captions in data packets of the MPEG-2 video streams inside of the Video-TS folder. Once played out of the analog outputs of a set top DVD player, the caption data is converted to the Line 21 format. They are output by the player to the composite video (or an available RF connector) for a connected TV's built-in decoder or a set-top decoder as usual. They can not be output on S-Video or component video outputs due to the lack of a colorburst signal on line 21. (Actually, regardless of this, if the DVD player is in interlaced rather than progressive mode, closed captioning will be displayed on the TV over component video input if the TV captioning is turned on and set to CC1.) When viewed on a personal computer, caption data can be viewed by software that can read and decode the caption data packets in the MPEG-2 streams of the DVD-Video disc. Windows Media Player (before Windows 7) in Vista supported only closed caption channels 1 and 2 (not 3 or 4). Apple's DVD Player does not have the ability to read and decode Line 21 caption data which are recorded on a DVD made from an over-the-air broadcast. It can display some movie DVD captions.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 149902, 79792, 156101, 288212, 148078, 43941, 326123, 856, 3405945 ], "anchor_spans": [ [ 264, 279 ], [ 297, 309 ], [ 406, 413 ], [ 417, 432 ], [ 462, 472 ], [ 882, 902 ], [ 911, 920 ], [ 992, 999 ], [ 1000, 1010 ] ] }, { "plaintext": "In addition to Line 21 closed captions, video DVDs may also carry subtitles, which generally rendered from the EIA-608 captions as a bitmap overlay that can be turned on and off via a set top DVD player or DVD player software, just like the textual captions. This type of captioning is usually carried in a subtitle track labeled either \"English for the hearing impaired\" or, more recently, \"SDH\" (subtitled for the deaf and Hard of hearing). Many popular Hollywood DVD-Videos can carry both subtitles and closed captions (e.g. Stepmom DVD by Columbia Pictures). On some DVDs, the Line 21 captions may contain the same text as the subtitles; on others, only the Line 21 captions include the additional non-speech information (even sometimes song lyrics) needed for deaf and hard-of-hearing viewers. European Region 2 DVDs do not carry Line 21 captions, and instead list the subtitle languages available-English is often listed twice, one as the representation of the dialogue alone, and a second subtitle set which carries additional information for the deaf and hard-of-hearing audience. (Many deaf/ subtitle files on DVDs are reworkings of original teletext subtitle files.)", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 1154851, 1632580 ], "anchor_spans": [ [ 111, 118 ], [ 528, 535 ] ] }, { "plaintext": "Blu-ray media cannot carry any VBI data such as Line 21 closed captioning due to the design of DVI-based High-Definition Multimedia Interface (HDMI) specifications that was only extended for synchronized digital audio replacing older analog standards, such as VGA, S-Video, component video, and SCART. Both Blu-ray and DVD can use either PNG bitmap subtitles or 'advanced subtitles' to carry SDH type subtitling, the latter being an XML-based textual format which includes font, styling and positioning information as well as a unicode representation of the text. Advanced subtitling can also include additional media accessibility features such as \"descriptive audio\".", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 11015826, 329829, 60980, 537442, 73041, 80765 ], "anchor_spans": [ [ 0, 7 ], [ 31, 34 ], [ 95, 98 ], [ 105, 141 ], [ 260, 263 ], [ 295, 300 ] ] }, { "plaintext": "There are several competing technologies used to provide captioning for movies in theaters. Cinema captioning falls into the categories of open and closed. The definition of \"closed\" captioning in this context is different from television, as it refers to any technology that allows as few as one member of the audience to view the captions.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Open captioning in a film theater can be accomplished through burned-in captions, projected text or bitmaps, or (rarely) a display located above or below the movie screen. Typically, this display is a large LED sign. In a digital theater, open caption display capability is built into the digital projector. Closed caption capability is also available, with the ability for 3rd-party closed caption devices to plug into the digital cinema server.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 13390326 ], "anchor_spans": [ [ 100, 106 ] ] }, { "plaintext": "Probably the best known closed captioning option for film theaters is the Rear Window Captioning System from the National Center for Accessible Media. Upon entering the theater, viewers requiring captions are given a panel of flat translucent glass or plastic on a gooseneck stalk, which can be mounted in front of the viewer's seat. In the back of the theater is an LED display that shows the captions in mirror image. The panel reflects captions for the viewer but is nearly invisible to surrounding patrons. The panel can be positioned so that the viewer watches the movie through the panel, and captions appear either on or near the movie image. A company called Cinematic Captioning Systems has a similar reflective system called Bounce Back. A major problem for distributors has been that these systems are each proprietary, and require separate distributions to the theater to enable them to work. Proprietary systems also incur license fees.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 815012, 484826, 18290 ], "anchor_spans": [ [ 74, 103 ], [ 113, 149 ], [ 367, 370 ] ] }, { "plaintext": "For film projection systems, Digital Theater Systems, the company behind the DTS surround sound standard, has created a digital captioning device called the DTS-CSS (Cinema Subtitling System). It is a combination of a laser projector which places the captioning (words, sounds) anywhere on the screen and a thin playback device with a CD that holds many languages. If the Rear Window Captioning System is used, the DTS-CSS player is also required for sending caption text to the Rear Window sign located in the rear of the theater.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 1754335, 253836, 6429 ], "anchor_spans": [ [ 29, 52 ], [ 81, 95 ], [ 335, 337 ] ] }, { "plaintext": "Special effort has been made to build accessibility features into digital projection systems (see digital cinema). Through SMPTE, standards now exist that dictate how open and closed captions, as well as hearing-impaired and visually impaired narrative audio, are packaged with the rest of the digital movie. This eliminates the proprietary caption distributions required for film, and the associated royalties. SMPTE has also standardized the communication of closed caption content between the digital cinema server and 3rd-party closed caption systems (the CSP/RPL protocol). As a result, new, competitive closed caption systems for digital cinema are now emerging that will work with any standards-compliant digital cinema server. These newer closed caption devices include cupholder-mounted electronic displays and wireless glasses which display caption text in front of the wearer's eyes. Bridge devices are also available to enable the use of Rear Window systems. As of mid-2010, the remaining challenge to the wide introduction of accessibility in digital cinema is the industry-wide transition to SMPTE DCP, the standardized packaging method for very high quality, secure distribution of digital movies.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 8844, 164346 ], "anchor_spans": [ [ 98, 112 ], [ 123, 128 ] ] }, { "plaintext": "Captioning systems have also been adopted by most major league and high-profile college stadiums and arenas, typically through dedicated portions of their main scoreboards or as part of balcony fascia LED boards. These screens display captions of the public address announcer and other spoken content, such as those contained within in-game segments, public service announcements, and lyrics of songs played in-stadium. In some facilities, these systems were added as a result of discrimination lawsuits. Following a lawsuit under the Americans with Disabilities Act, FedExField added caption screens in 2006. Some stadiums utilize on-site captioners while others outsource them to external providers who caption remotely.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 185604, 180244, 1520925, 5581765, 504807, 1338, 395592 ], "anchor_spans": [ [ 88, 95 ], [ 101, 106 ], [ 160, 170 ], [ 194, 200 ], [ 251, 265 ], [ 535, 566 ], [ 568, 578 ] ] }, { "plaintext": "The infrequent appearance of closed captioning in video games became a problem in the 1990s as games began to commonly feature voice tracks, which in some cases contained information which the player needed in order to know how to progress in the game. Closed captioning of video games is becoming more common. One of the first video game companies to feature closed captioning was Bethesda Softworks in their 1990 release of Hockey League Simulator and The Terminator 2029. Infocom also offered Zork Grand Inquisitor in 1997. Many games since then have at least offered subtitles for spoken dialog during cutscenes, and many include significant in-game dialog and sound effects in the captions as well; for example, with subtitles turned on in the Metal Gear Solid series of stealth games, not only are subtitles available during cut scenes, but any dialog spoken during real-time gameplay will be captioned as well, allowing players who can't hear the dialog to know what enemy guards are saying and when the main character has been detected. Also, in many of developer Valve's video games (such as Half-Life 2 or Left 4 Dead), when closed captions are activated, dialog and nearly all sound effects either made by the player or from other sources (e.g. gunfire, explosions) will be captioned.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 5363, 143382, 7764345, 875467, 59288871, 379018, 52842, 575509, 8036013 ], "anchor_spans": [ [ 50, 60 ], [ 382, 400 ], [ 454, 473 ], [ 496, 517 ], [ 606, 614 ], [ 749, 765 ], [ 1072, 1077 ], [ 1101, 1112 ], [ 1116, 1127 ] ] }, { "plaintext": "Video games don't offer Line 21 captioning, decoded and displayed by the television itself but rather a built-in subtitle display, more akin to that of a DVD. The game systems themselves have no role in the captioning either; each game must have its subtitle display programmed individually.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Reid Kimball, a game designer who is hearing impaired, is attempting to educate game developers about closed captioning for games. Reid started the Games[CC] group to closed caption games and serve as a research and development team to aid the industry. Kimball designed the Dynamic Closed Captioning system, writes articles and speaks at developer conferences. Games[CC]'s first closed captioning project called Doom3[CC] was nominated for an award as Best Doom3 Mod of the Year for IGDA's Choice Awards 2006 show.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Internet video streaming service YouTube offers captioning services in videos. The author of the video can upload a SubViewer (*.SUB), SubRip (*.SRT) or *.SBV file. As a beta feature, the site also added the ability to automatically transcribe and generate captioning on videos, with varying degrees of success based upon the content of the video. However, on August 30, 2020, the company announced that communal captions will end on September 28. The automatic captioning is often inaccurate on videos with background music or exaggerated emotion in speaking. Variations in volume can also result in nonsensical machine-generated captions. Additional problems arise with strong accents, sarcasm, differing contexts, or homonyms.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 3524766, 2675737, 19593964, 148126 ], "anchor_spans": [ [ 33, 40 ], [ 135, 141 ], [ 688, 695 ], [ 720, 727 ] ] }, { "plaintext": "On June 30, 2010, YouTube announced a new \"YouTube Ready\" designation for professional caption vendors in the United States. The initial list included twelve companies who passed a caption quality evaluation administered by the Described and Captioned Media Project, have a website and a YouTube channel where customers can learn more about their services and have agreed to post rates for the range of services that they offer for YouTube content.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Flash video also supports captions using the Distribution Exchange profile (DFXP) of W3C timed text format. The latest Flash authoring software adds free player skins and caption components that enable viewers to turn captions on/off during playback from a web page. Previous versions of Flash relied on the Captionate 3rd party component and skin to caption Flash video. Custom Flash players designed in Flex can be tailored to support the timed-text exchange profile, Captionate .XML, or SAMI file (e.g. Hulu captioning). This is the preferred method for most US broadcast and cable networks that are mandated by the U.S. Federal Communications Commission to provide captioned on-demand content. The media encoding firms generally use software such as MacCaption to convert EIA-608 captions to this format. The Silverlight Media Framework also includes support for the timed-text exchange profile for both download and adaptive streaming media.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 2472154, 5140187, 34138, 7089081, 1350109, 3434750, 55974, 12996890, 1154851, 9731719 ], "anchor_spans": [ [ 0, 11 ], [ 89, 99 ], [ 481, 485 ], [ 490, 494 ], [ 506, 510 ], [ 562, 564 ], [ 624, 657 ], [ 754, 764 ], [ 776, 783 ], [ 813, 824 ] ] }, { "plaintext": "Windows Media Video can support closed captions for both video on demand streaming or live streaming scenarios. Typically, Windows Media captions support the SAMI file format but can also carry embedded closed caption data.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 225169, 7089081 ], "anchor_spans": [ [ 0, 19 ], [ 158, 162 ] ] }, { "plaintext": "EBU-TT-D distribution format supports multiple players across multiple platforms.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "QuickTime video supports raw EIA-608 caption data via proprietary closed caption track, which are just EIA-608 byte pairs wrapped in a QuickTime packet container with different IDs for both line 21 fields. These captions can be turned on and off and appear in the same style as TV closed captions, with all the standard formatting (pop-on, roll-up, paint-on), and can be positioned and split anywhere on the video screen. QuickTime closed caption tracks can be viewed in Macintosh or Windows versions of QuickTime Player, iTunes (via QuickTime), iPod Nano, iPod Classic, iPod Touch, iPhone, and iPad.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 1154851, 1154851, 25231, 19006979, 18890, 25231, 186266, 2635169, 13111157, 13111239, 8841749, 25970423 ], "anchor_spans": [ [ 29, 36 ], [ 103, 110 ], [ 135, 144 ], [ 471, 480 ], [ 484, 491 ], [ 504, 513 ], [ 522, 528 ], [ 546, 555 ], [ 557, 569 ], [ 571, 581 ], [ 583, 589 ], [ 595, 599 ] ] }, { "plaintext": "Live plays can be open captioned by a captioner who displays lines from the script and including non-speech elements on a large display screen near the stage. Software is also now available that automatically generates the captioning and streams the captioning to individuals sitting in the theater, with that captioning being viewed using heads-up glasses or on a smartphone or computer tablet.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 83597, 2238936 ], "anchor_spans": [ [ 76, 82 ], [ 128, 142 ] ] }, { "plaintext": "A captioned telephone is a telephone that displays real-time captions of the current conversation. The captions are typically displayed on a screen embedded into the telephone base.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 30003 ], "anchor_spans": [ [ 27, 36 ] ] }, { "plaintext": "Some online video conferencing services, such as Google Meet, offer the ability to display captions in real time of the current conversation.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 61677706 ], "anchor_spans": [ [ 49, 60 ] ] }, { "plaintext": "In the United States especially, most media monitoring services capture and index closed captioning text from news and public affairs programs, allowing them to search the text for client references. The use of closed captioning for television news monitoring was pioneered by Universal Press Clipping Bureau (Universal Information Services) in 1992, and later in 1993 by Tulsa-based NewsTrak of Oklahoma (later known as Broadcast News of Mid-America, acquired by video news release pioneer Medialink Worldwide Incorporated in 1997). US patent 7,009,657 describes a \"method and system for the automatic collection and conditioning of closed caption text originating from multiple geographic locations\" as used by news monitoring services.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 1016832, 668894 ], "anchor_spans": [ [ 38, 62 ], [ 464, 482 ] ] }, { "plaintext": "Software programs are available that automatically generate a closed-captioning of conversations. Examples of such conversations include discussions in conference rooms, classroom lectures, or religious services.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "In 2010, Vegas Pro, the professional non-linear editor, was updated to support importing, editing, and delivering CEA-608 closed captions. Vegas Pro 10, released on October 11, 2010, added several enhancements to the closed captioning support. TV-like CEA-608 closed captioning can now be displayed as an overlay when played back in the Preview and Trimmer windows, making it easy to check placement, edits, and timing of CC information. CEA708 style Closed Captioning is automatically created when the CEA-608 data is created. Line 21 closed captioning is now supported, as well as HD-SDI closed captioning capture and print from AJA and Blackmagic Design cards. Line 21 support provides a workflow for existing legacy media. Other improvements include increased support for multiple closed captioning file types, as well as the ability to export closed caption data for DVD Architect, YouTube, RealPlayer, QuickTime, and Windows Media Player.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 1409254, 1154851, 35539399 ], "anchor_spans": [ [ 9, 18 ], [ 114, 121 ], [ 639, 656 ] ] }, { "plaintext": "In mid-2009, Apple released Final Cut Pro version 7 and began support for inserting closed caption data into SD and HD tape masters via FireWire and compatible video capture cards. Up until this time, it was not possible for video editors to insert caption data with both CEA-608 and CEA-708 to their tape masters. The typical workflow included first printing the SD or HD video to a tape and sending it to a professional closed caption service company that had a stand-alone closed caption hardware encoder.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 856, 461771, 26246088, 1154851, 1149687 ], "anchor_spans": [ [ 13, 18 ], [ 28, 41 ], [ 136, 144 ], [ 272, 279 ], [ 284, 291 ] ] }, { "plaintext": "This new closed captioning workflow known as e-Captioning involves making a proxy video from the non-linear system to import into a third-party non-linear closed captioning software. Once the closed captioning software project is completed, it must export a closed caption file compatible with the non-linear editing system. In the case of Final Cut Pro 7, three different file formats can be accepted: a .SCC file (Scenarist Closed Caption file) for Standard Definition video, a QuickTime 608 closed caption track (a special 608 coded track in the .mov file wrapper) for standard-definition video, and finally a QuickTime 708 closed caption track (a special 708 coded track in the .mov file wrapper) for high-definition video output.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 25809999, 70729, 25231 ], "anchor_spans": [ [ 45, 57 ], [ 298, 323 ], [ 480, 489 ] ] }, { "plaintext": "Alternatively, Matrox video systems devised another mechanism for inserting closed caption data by allowing the video editor to include CEA-608 and CEA-708 in a discrete audio channel on the video editing timeline. This allows real-time preview of the captions while editing and is compatible with Final Cut Pro 6 and 7.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [ 100468 ], "anchor_spans": [ [ 15, 21 ] ] }, { "plaintext": "Other non-linear editing systems indirectly support closed captioning only in Standard Definition line-21. Video files on the editing timeline must be composited with a line-21 VBI graphic layer known in the industry as a \"blackmovie\" with closed caption data. Alternately, video editors working with the DV25 and DV50 FireWire workflows must encode their DV .avi or .mov file with VAUX data which includes CEA-608 closed caption data.", "section_idx": 6, "section_name": "Uses in other media", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The current and most familiar logo for closed captioning consists of two Cs (for \"closed captioned\") inside a television screen. It was created at WGBH. The other logo, trademarked by the National Captioning Institute, is that of a simple geometric rendering of a television set merged with the tail of a speech balloon; two such versions exist one with a tail on the left, the other with a tail on the right.", "section_idx": 7, "section_name": "Logo", "target_page_ids": [ 5200013, 484826, 18935023, 5247207, 628485, 1187874 ], "anchor_spans": [ [ 73, 74 ], [ 147, 151 ], [ 169, 178 ], [ 188, 217 ], [ 264, 278 ], [ 305, 319 ] ] }, { "plaintext": " Speech-to-text reporter (captioner), an occupation", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 12689044 ], "anchor_spans": [ [ 1, 24 ] ] }, { "plaintext": " Fansub", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 154208 ], "anchor_spans": [ [ 1, 7 ] ] }, { "plaintext": " Same Language Subtitling", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 21466202 ], "anchor_spans": [ [ 1, 25 ] ] }, { "plaintext": " Synchronized Accessible Media Interchange (SAMI) file format", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 7089081 ], "anchor_spans": [ [ 1, 42 ] ] }, { "plaintext": " Sign language on television", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 27699 ], "anchor_spans": [ [ 1, 28 ] ] }, { "plaintext": " Subtitle (captioning)", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 7224224 ], "anchor_spans": [ [ 1, 22 ] ] }, { "plaintext": " Surtitles", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 30862699 ], "anchor_spans": [ [ 1, 10 ] ] }, { "plaintext": " Synchronized Multimedia Integration Language (SMIL) file format", "section_idx": 8, "section_name": "See also", "target_page_ids": [ 28704 ], "anchor_spans": [ [ 1, 45 ] ] }, { "plaintext": "Sources", "section_idx": 9, "section_name": "References", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Realtime Captioning... The VITAC Way by Amy Bowlen and Kathy DiLorenzo (no ISBN)", "section_idx": 9, "section_name": "References", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " BBC Subtitles (Captions) Editorial Guidelines ", "section_idx": 9, "section_name": "References", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Closed Captioning: Subtitling, Stenography, and the Digital Convergence of Text with Television by Gregory J. Downey ()", "section_idx": 9, "section_name": "References", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " The Closed Captioning Handbook by Gary D. Robson ()", "section_idx": 9, "section_name": "References", "target_page_ids": [ 39057234 ], "anchor_spans": [ [ 35, 49 ] ] }, { "plaintext": " Alternative Realtime Careers: A Guide to Closed Captioning and CART for Court Reporters by Gary D. Robson ()", "section_idx": 9, "section_name": "References", "target_page_ids": [ 39057234 ], "anchor_spans": [ [ 92, 106 ] ] }, { "plaintext": " A New Civil Right: Telecommunications Equality for Deaf and Hard of Hearing Americans by Karen Peltz Strauss ()", "section_idx": 9, "section_name": "References", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Enabling The Disabled'' by Michael Karagosian (no ISBN)", "section_idx": 9, "section_name": "References", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Closed Captioning of Video Programming - 47 C.F.R. 79.1-From the Federal Communications Commission Consumer & Governmental Affairs Bureau", "section_idx": 10, "section_name": "External links", "target_page_ids": [ 55974 ], "anchor_spans": [ [ 65, 98 ] ] }, { "plaintext": " FCC Consumer Facts on Closed Captioning ", "section_idx": 10, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Alan Newell, Inventor of Closed Captioning, Teletext for the Deaf, 1982", "section_idx": 10, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " Closed Captioned TV: A Resource for ESL Literacy Education-From the Education Resources Information Center Clearinghouse for ESL Literacy Education, Washington D.C.", "section_idx": 10, "section_name": "External links", "target_page_ids": [ 1958099 ], "anchor_spans": [ [ 69, 107 ] ] }, { "plaintext": " Bill Kastner: The Man Behind Closed Captioning", "section_idx": 10, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " First Sears Telecaption adapter advertised in 1980 Sears catalog", "section_idx": 10, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " BBC Best Practice Guidelines for Captioning and Subtitling (UK)", "section_idx": 10, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " EBU-TT-D Subtitling (Captions) Distribution Format", "section_idx": 10, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Untertitel", "section_idx": 10, "section_name": "External links", "target_page_ids": [], "anchor_spans": [] } ]

[ "Subtitling", "Assistive_technology", "Deafness", "Television_terminology", "High-definition_television", "Transcription_(linguistics)" ]

[ "CC", "closed captions" ]

[ { "plaintext": "A closed-loop transfer function in control theory is a mathematical expression (algorithm) describing the net result of the effects of a closed (feedback) loop on the input signal to the plant under control.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 7039, 775, 11545, 160478, 275871, 13675124 ], "anchor_spans": [ [ 35, 49 ], [ 80, 89 ], [ 145, 153 ], [ 155, 159 ], [ 173, 179 ], [ 187, 192 ] ] }, { "plaintext": "The closed-loop transfer function is measured at the output. The output signal can be calculated from the closed-loop transfer function and the input signal. Signals may be waveforms, images, or other types of data streams.", "section_idx": 1, "section_name": "Overview", "target_page_ids": [ 31146, 47592, 71925, 47868 ], "anchor_spans": [ [ 16, 33 ], [ 174, 183 ], [ 185, 191 ], [ 211, 223 ] ] }, { "plaintext": "An example of a closed-loop transfer function is shown below:", "section_idx": 1, "section_name": "Overview", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "The summing node and the G(s) and H(s) blocks can all be combined into one block, which would have the following transfer function:", "section_idx": 1, "section_name": "Overview", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": " is called feedforward transfer function, is called feedback transfer function, and their product is called the Open loop transfer function.", "section_idx": 1, "section_name": "Overview", "target_page_ids": [ 62234667, 11545 ], "anchor_spans": [ [ 11, 22 ], [ 53, 61 ] ] }, { "plaintext": "We define an intermediate signal Z (also known as error signal) shown as follows:", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [ 325496 ], "anchor_spans": [ [ 50, 62 ] ] }, { "plaintext": "Using this figure we write:", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Now, plug the second equation into the first to eliminate Z(s):", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Move all the terms with Y(s) to the left hand side, and keep the term with X(s) on the right hand side:", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Therefore,", "section_idx": 2, "section_name": "Derivation", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Federal Standard 1037C", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 37310 ], "anchor_spans": [ [ 0, 22 ] ] }, { "plaintext": "Open-loop controller", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 564756 ], "anchor_spans": [ [ 0, 20 ] ] }, { "plaintext": "Open-Loop Transfer Function", "section_idx": 3, "section_name": "See also", "target_page_ids": [], "anchor_spans": [] }, { "plaintext": "Control_theory", "section_idx": 3, "section_name": "See also", "target_page_ids": [ 7039 ], "anchor_spans": [ [ 0, 14 ] ] } ]

[ "Classical_control_theory", "Cybernetics" ]

[]

[ { "plaintext": "In telecommunication, the term code conversion has the following meanings: ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374 ], "anchor_spans": [ [ 3, 20 ] ] }, { "plaintext": "1. Conversion of signals, or groups of signals, in one code into corresponding signals, or groups of signals, in another code. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 5225 ], "anchor_spans": [ [ 56, 60 ] ] }, { "plaintext": "2. A process for converting a code of some predetermined bit structure, such as 5, 7, or 14 bits per character interval, to another code with the same or a different number of bits per character interval. ", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 3364, 40865 ], "anchor_spans": [ [ 58, 61 ], [ 102, 120 ] ] }, { "plaintext": "In code conversion, alphabetical order is not significant.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [], "anchor_spans": [] } ]

[ "Line_codes" ]

[]

[ { "plaintext": "In telecommunication, a coded set is a set of elements onto which another set of elements has been mapped according to a code.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 33094374, 26691, 5225 ], "anchor_spans": [ [ 3, 20 ], [ 39, 42 ], [ 121, 125 ] ] }, { "plaintext": "Examples of coded sets include the list of names of airports that is mapped onto a set of corresponding three-letter representations of airport names, the list of classes of emission that is mapped onto a set of corresponding standard symbols, and the names of the months of the year mapped onto a set of two-digit decimal numbers.", "section_idx": 0, "section_name": "Introduction", "target_page_ids": [ 150179, 27065, 280582 ], "anchor_spans": [ [ 104, 149 ], [ 226, 234 ], [ 309, 314 ] ] } ]

[ "Telecommunication_theory" ]

[]