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In telecommunication, a burst error or error burst is a contiguous sequence of symbols, received over a data transmission channel, such that the first and last symbols are in error and there exists no contiguous subsequence of ''m'' correctly received symbols within the error burst. The integer parameter ''m'' is referred to as the guard band of the error burst. The last symbol in a burst and the first symbol in the following burst are accordingly separated by ''m'' correct bits or more. The parameter ''m'' should be specified when describing an error burst. For example, imagine sending a packet containing all of the letters of the alphabet, A through Z. If the recipient's computer "opens" the packet and finds that the first letter in the sequence is "Q" and the last letter in the sequence is "R," that is a burst error. The "burst" of data in the packet is corrupt. Although in the example the first and last letters are defined as corrupt, that does not mean that every letter within the packet is damaged. Imagine that every other letter is as it should be; only position one, "A," and position 26, "Z," have been damaged. The number of correct bits of information between the damaged ends is called the guard band. In this case, the guard band would be 24, because there are 24 correct letters separating the two damaged ones. ==Channel model== The Gilbert–Elliott model is a simple channel model introduced by Edgar Gilbert〔.〕 and E. O. Elliott 〔.〕 widely used for describing burst error patterns in transmission channels, that enables simulations of the digital error performance of communications links. It is based on a Markov chain with two states ''G'' (for good or gap) and ''B'' (for bad or burst). In state ''G'' the probability of transmitting a bit correctly is ''k'' and in state ''B'' it is ''h''. Usually,〔Lemmon, J.J.: Wireless link statistical bit error model. US National Telecommunications and Information Administration (NTIA) Report 02-394 (2002)〕 it is assumed that ''k'' = 1. Gilbert provided equations for deriving the other three parameters (''G'' and ''B'' state transition probabilities and ''h'') from a given success/failure sequence. In his example, the sequence was too short to correctly find ''h'' (a negative probability was found) and so Gilbert assumed that ''h'' = 0.5. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「burst error」の詳細全文を読む スポンサード リンク
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