{{short description|Contiguous sequence of errors occurring in a communications channel}}
In telecommunications, a '''burst error''' or '''error burst''' is a contiguous sequence of symbols, received over a communication 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.<ref>{{citation|title=Federal Standard 1037C|url=http://www.its.bldrdoc.gov/fs-1037/fs-1037c.htm}}</ref> 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 symbols or more. The parameter ''m'' should be specified when describing an error burst.
==Channel model==
The '''Gilbert–Elliott model''' is a simple channel model introduced by Edgar Gilbert<ref>{{citation|last=Gilbert|first=E. N.|author-link=Edgar Gilbert|title=Capacity of a burst-noise channel|journal=Bell System Technical Journal|volume=39|year=1960|issue=5|pages=1253–1265|doi=10.1002/j.1538-7305.1960.tb03959.x}}.</ref> and E. O. Elliott <ref>{{citation|last=Elliott|first=E. O.|title=Estimates of error rates for codes on burst-noise channels|journal=Bell System Technical Journal|volume=42|year=1963|issue=5|pages=1977–1997|doi=10.1002/j.1538-7305.1963.tb00955.x}}.</ref> that is widely used for describing burst error patterns in transmission channels and 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,<ref>Lemmon, J.J.: Wireless link statistical bit error model. US National Telecommunications and Information Administration (NTIA) Report 02-394 (2002)</ref> 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.
== See also == * Burst error-correcting code
== References == {{Reflist}}
== External links == * {{web archive |url=https://web.archive.org/web/20200729154043/https://www.net.t-labs.tu-berlin.de/papers/HH-GEMPLRTSI-08.pdf |title=The Gilbert-Elliott Model for Packet Loss in Real Time Services on the Internet}} * {{web archive |url=https://web.archive.org/web/20200727052953/http://bnrg.cs.berkeley.edu/~adj/publications/paper-files/winet01.pdf |title=A Markov-Based Channel Model Algorithm for Wireless Networks}} * [http://www.wirelesscommunication.nl/reference/chaptr03/fading/gilbert.htm The two-state model for a fading channel]
Category:Markov models Category:Data transmission