In
telecommunications
Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than tha ...
and
data communication
Data transmission and data reception or, more broadly, data communication or digital communications is the transfer and reception of data in the form of a digital bitstream or a digitized analog signal transmitted over a point-to-point or ...
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
In digital transmission, the number of bit errors is the number of received bits of a data stream over a communication channel that have been altered due to noise, interference, distortion or bit synchronization errors.
The bit error rate (BER ...
s, such as modern
fiber optic transmission system
Fiber-optic communication is a method of transmitting information from one place to another by sending pulses of infrared light through an optical fiber. The light is a form of carrier wave that is modulated to carry information. Fiber is pr ...
s, or systems with higher low-level error rates that are corrected using large amounts of
forward error correction
In computing, telecommunication, information theory, and coding theory, an error correction code, sometimes error correcting code, (ECC) is used for controlling errors in data over unreliable or noisy communication channels. The central idea is ...
, errored seconds are often a better measure of the effective user-visible error rate than the 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
In telecommunications and computer networking, a network packet is a formatted unit of data carried by a packet-switched network. A packet consists of control information and user data; the latter is also known as the ''payload''. Control informa ...
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
In telecommunication, 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 rec ...
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.
See also
*
Degraded minute
*
Severely errored second
*
Channel bit error rate
External links
Cisco DS1, T1 and E1 Glossary
{{telecom-stub
Data transmission
Network performance
Error measures