Errored second: Difference between revisions

Revision as of 08:11, 2 January 2011

Revision as of 08:15, 2 January 2011

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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 communication systems with very low uncorrected [[bit error rate]]s, such as modern [[fiber optic transmission system]]s, or systems 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-switched communication systems, even a single uncorrected bit error is enough to cause the loss of a [[data packet]] by causing its [[CRC]] to fail; whether that packet loss was caused by a single bit error or a burst of 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.

More specialist and precise definitions of errored seconds exist in standards such as the [[T1]] and [[DS1]] transport systems.