Errored second: Difference between revisions

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{{Short description|Metric for digital communication link}}
In [[telecommunications]] and [[data communication]] systems, an '''errored second''' is an interval of a [[second]] during which any error whatsoever has occurred, regardless of whether that error was a single bit error, or a complete loss of communication for that entire second, is not important for the purpose of counting errored seconds.
 
In [[telecommunications]] and [[data communication]] systems, an '''errored second''' is an interval of a [[second]] during which any error whatsoever has occurred, regardless of whether that error was a single bit error, or a complete loss of communication for that entire second,. The type of error is not important for the purpose of counting errored seconds.
In communication systems with very low uncorrected [[bit error rate]]s, such as modern [[fiber optic transmission system]]s, or systems with higher low-level error rates that are corrected using large amounts of [[forward error correction]], errored seconds are often a better measure of effective error rate than simple bit error rate.
 
For many modern packet-switchedIn communication systems, evenwith avery singlelow uncorrected [[bit error israte]]s, enoughsuch toas cause the loss of amodern [[datafiber-optic transmission packetsystem]]s, byor causingsystems itswith [[CRChigher check]]low-level to fail;error whetherrates that packetare losscorrected wasusing causedlarge byamounts aof single bit[[forward error orcorrection]], errored seconds are often a burstbetter measure of athe hundred-biteffective user-longvisible [[error burst]]rate isthan irrelevantthe raw bit error rate.
 
For many modern packet-switched communication systems, even a single uncorrected bit error is enough to cause the loss of a [[data packet]] by causing its [[CRC check]] to fail; whether that packet loss was caused by a single bit error or a hundred-bit-long [[error burst]] is irrelevant.
For systems using large amounts of forward error correction, the reverse applies; a single low-level bit error will almost never occur, since any small errors will almost always be corrected, but any error sufficiently large to cause the forward error correction to fail will almost always result in a large burst error.
 
For systems using large amounts of forward error correction, the reverse applies; a single low-level bit error will almost never occur, since any small errors will almost always be corrected, but any error sufficiently large to cause the forward error correction to fail will almost always result in a large burst error.
More specialist and precise definitions of errored seconds exist in standards such as the [[T1]] and [[DS1]] transport systems.
 
More specialist and precise definitions of errored seconds exist in standards such as the [[Digital Signal 1|T1]] and [[Digital Signal 1|DS1]] transport systems.
== See also ==
* [[Degraded minute]]
* [[Severely errored second]]
* [[Channel bit error rate]]
 
== External linksReferences ==
* [http://www.cisco.com/en/US/tech/tk713/tk628/technologies_tech_note09186a00800f2fa1.shtml Cisco DS1, T1 and E1 Glossary]
 
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[[Category:Data transmission]]
[[Category:Network performance]]
[[Category:Error measures]]
[[Category:Telecommunications]]