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Block Check Character
In telecommunications, a block check character (BCC) is a character added to a transmission block to facilitate error detection. In longitudinal redundancy checking and cyclic redundancy checking, block check characters are computed for, and added to, each message A message is a discrete unit of communication intended by the source for consumption by some recipient or group of recipients. A message may be delivered by various means, including courier, telegraphy, carrier pigeon and electronic bus. A ... 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. Control characters {{telecom-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telecommunication
Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than that feasible with the human voice, but with a similar scale of expediency; thus, slow systems (such as postal mail) are excluded from the field. The transmission media in telecommunication have evolved through numerous stages of technology, from beacons and other visual signals (such as smoke signals, semaphore telegraphs, signal flags, and optical heliographs), to electrical cable and electromagnetic radiation, including light. Such transmission paths are often divided into communication channels, which afford the advantages of multiplexing multiple concurrent communication sessions. ''Telecommunication'' is often used in its plural form. Other examples of pre-modern long-distance communication included audio messages, such as coded drumb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Character (computing)
In computer and machine-based telecommunications terminology, a character is a unit of information that roughly corresponds to a grapheme, grapheme-like unit, or symbol, such as in an alphabet or syllabary in the written form of a natural language. Examples of characters include letters, numerical digits, common punctuation marks (such as "." or "-"), and whitespace. The concept also includes control characters, which do not correspond to visible symbols but rather to instructions to format or process the text. Examples of control characters include carriage return and tab as well as other instructions to printers or other devices that display or otherwise process text. Characters are typically combined into strings. Historically, the term ''character'' was used to denote a specific number of contiguous bits. While a character is most commonly assumed to refer to 8 bits (one byte) today, other options like the 6-bit character code were once popular, and the 5-bit Baudot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmission Block
In telecommunication, the term transmission block has the following meanings: #A group of characters or bits transmitted as a block, unit, message, or packet. It usually includes additional encoded characters for error detection and correction. #In data transmission, a group of records sent, processed, or recorded as a unit. Some protocols require each transmission block to end with an end-of-message marker. This is often a control character such as End-of-Text (ETX), End-of-Transmission-Block (ETB), or End-of-Transmission (EOT). Some protocols (especially those requiring ETX) require each transmission block to begin with a Start-of-Text character (STX). See also *Frame (networking) *Network packet In telecommunications and computer networking, a network packet is a formatted unit of data carried by a packet-switched network. A packet consists of control information and user data; the latter is also known as the ''payload''. Control informa ... References *{{FS1037C Dat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Error Detection
In information theory and coding theory with applications in computer science and telecommunication, error detection and correction (EDAC) or error control are techniques that enable reliable delivery of digital data over unreliable communication channels. Many communication channels are subject to channel noise, and thus errors may be introduced during transmission from the source to a receiver. Error detection techniques allow detecting such errors, while error correction enables reconstruction of the original data in many cases. Definitions ''Error detection'' is the detection of errors caused by noise or other impairments during transmission from the transmitter to the receiver. ''Error correction'' is the detection of errors and reconstruction of the original, error-free data. History In classical antiquity, copyists of the Hebrew Bible were paid for their work according to the number of stichs (lines of verse). As the prose books of the Bible were hardly ever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Longitudinal Redundancy Check
In telecommunication, a longitudinal redundancy check (LRC), or horizontal redundancy check, is a form of redundancy check that is applied independently to each of a parallel group of bit streams. The data must be divided into transmission blocks, to which the additional check data is added. The term usually applies to a single parity bit per bit stream, calculated independently of all the other bit streams ( BIP-8), : "Reliable link layer protocols". although it could also be used to refer to a larger Hamming code. This "extra" LRC word at the end of a block of data is very similar to checksum and cyclic redundancy check (CRC). Optimal rectangular code While simple longitudinal parity can only detect errors, it can be combined with additional error-control coding, such as a transverse redundancy check (TRC), to correct errors. The transverse redundancy check is stored on a dedicated "parity track". Whenever any single-bit error occurs in a transmission block of data, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclic Redundancy Check
A cyclic redundancy check (CRC) is an error-detecting code commonly used in digital networks and storage devices to detect accidental changes to digital data. Blocks of data entering these systems get a short ''check value'' attached, based on the remainder of a polynomial division of their contents. On retrieval, the calculation is repeated and, in the event the check values do not match, corrective action can be taken against data corruption. CRCs can be used for error correction (see bitfilters). CRCs are so called because the ''check'' (data verification) value is a ''redundancy'' (it expands the message without adding information) and the algorithm is based on ''cyclic'' codes. CRCs are popular because they are simple to implement in binary hardware, easy to analyze mathematically, and particularly good at detecting common errors caused by noise in transmission channels. Because the check value has a fixed length, the function that generates it is occasionally used as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Message
A message is a discrete unit of communication intended by the source for consumption by some recipient or group of recipients. A message may be delivered by various means, including courier, telegraphy, carrier pigeon and electronic bus. A message can be the content of a broadcast. An interactive exchange of messages forms a conversation. One example of a message is a press release, which may vary from a brief report or statement released by a public agency to commercial publicity material. History Roles in human communication In communication between humans, messages can be verbal or nonverbal: * A verbal message is an exchange of information using words. Examples include face-to-face communication, telephone calls, voicemails, email etc. * A nonverbal message is communicated through actions or behaviors rather than words, such as conscious or unconscious body language. In computer science There are two main senses of the word "message" in computing: messages be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
