Editing Burst error

{{short description|Contiguous sequence of errors occurring in a communications channel}}
{{expand German|date=August 2020}}

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 transmission|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&nbsp;''k''&nbsp;=&nbsp;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&nbsp;''h''&nbsp;=&nbsp;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]]