56 kbps

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.

(1998-09-15)