<communications> (56 kilobits per second) The data capacity of
a normal single channel digital telephone channel in North
America. The figure is derived from the bandwidth of 4 kHz
allocated for such a channel and the 16-bit encoding (4000
times 16 = 64000) used to change analogue signals to
digital, minus the 8000 bit/s used for signalling and
supervision.
At the end of 1997 there were two rival modem designs
capable of this rate: k56flex and US Robotics' X2. In
February 1998 the ITU proposed a 56kbps standard called
V.90, which is expected to be formally approved during
September 1998.
