Error burst
Encyclopedia
In telecommunication
Telecommunication
Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...

, a burst error or error burst is a contiguous sequence
Sequence
In mathematics, a sequence is an ordered list of objects . Like a set, it contains members , and the number of terms is called the length of the sequence. Unlike a set, order matters, and exactly the same elements can appear multiple times at different positions in the sequence...

 of symbols, received over a data transmission
Data transmission
Data transmission, digital transmission, or digital communications is the physical transfer of data over a point-to-point or point-to-multipoint communication channel. Examples of such channels are copper wires, optical fibres, wireless communication channels, and storage media...

 channel
Channel (communications)
In telecommunications and computer networking, a communication channel, or channel, refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel...

, such that the first and last symbols are in error
Error
The word error entails different meanings and usages relative to how it is conceptually applied. The concrete meaning of the Latin word "error" is "wandering" or "straying". Unlike an illusion, an error or a mistake can sometimes be dispelled through knowledge...

 and there exists no contiguous subsequence of m correctly received symbols within the error burst
Burst
Burst may refer to:*Burst mode , a mode of operation where events occur in rapid succession**Burst transmission, a term in telecommunications**Burst switching, a feature of some packet-switched networks**Bursting, a signaling mode of neurons...

.

The integer parameter m is referred to as the guard band
Guard band
-Radio and electronic signalling:In radio, a guard band is an unused part of the radio spectrum between radio bands, for the purpose of preventing interference....

 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.

The length of a burst of bit errors in a frame is defined as the number of bits from the first error to the last, inclusive.

Channel model

The Gilbert–Elliott model is a simple channel model introduced by Edgar Gilbert
Edgar Gilbert
Edgar Nelson Gilbert was an American mathematician and coding theorist, a longtime researcher at Bell Laboratories whose accomplishments include the Gilbert–Varshamov bound in coding theory, the Gilbert–Elliott model of bursty errors in signal transmission, and the Erdős–Rényi model for random...

 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
Markov chain
A Markov chain, named after Andrey Markov, is a mathematical system that undergoes transitions from one state to another, between a finite or countable number of possible states. It is a random process characterized as memoryless: the next state depends only on the current state and not on the...

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, it is assumed that k = 1 and Gilbert also assumed that h = 0.5.

External links

  • http://www.net.t-labs.tu-berlin.de/papers/HH-GEMPLRTSI-08.pdf
  • http://bnrg.cs.berkeley.edu/~adj/publications/paper-files/winet01.pdf
  • http://www.wirelesscommunication.nl/reference/chaptr03/fading/gilbert.htm
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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