baud rate ==>
baud
<communications, unit> /bawd/ (plural "baud") The unit in which the
information carrying capacity or "signalling rate" of a communication channel is
measured. One baud is one symbol (state-transition or level-transition) per
second. This coincides with bits per second only for two-level modulation with
no framing or stop bits.
A symbol is a unique state of the communication channel, distinguishable by the
receiver from all other possible states. For example, it may be one of two
voltage levels on a wire for a direct digital connection or it might be the
phase or frequency of a carrier.
The term "baud" was originally a unit of telegraph signalling speed, set at one
Morse code dot per second. Or, more generally, the reciprocal of the duration of
the shortest signalling element. It was proposed at the International Telegraph
Conference of 1927, and named after J.M.E. Baudot (1845-1903), the French
engineer who constructed the first successful teleprinter.
The UK PSTN will support a maximum rate of 600 baud but each baud may carry
between 1 and 16 bits depending on the coding (e.g. QAM).
Where data is transmitted as packets, e.g. characters, the actual "data rate" of
a channel is
R D / P
where R is the "raw" rate in bits per second, D is the number of data bits
in a packet and P is the total number of bits in a
packet (including packet overhead).
The term "baud" causes much confusion and is usually best avoided. Use "bits per
second" (bps), "bytes per second" or "characters per second" (cps) if that's
what you mean.
(1998-02-14)
Nearby terms:
batch file « batch processing « bathtub curve «
baud
» baud barf » Baudot » Baudotbetical order
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