A special type of Time Division Multiplexer designed to accept 24 analog voice channels, to convert each voice channel to 64 kbps PCM digital voice, and to format the resulting information into a 1.544 Mbps "T1" data stream.
Equipment in the central office that performs various necessary functions so that the ISDN circuit can operate properly. Multiplexes lower speed digital channels into a higher speed composite channel, among other things. Also may be used as CPE on T1 or other high-speed data circuits.
(1) A part of the carrier system that performs the first step of modulation. (2) A multiplexer that modulates a group of channels into a higher frequency band and, conversely, demultiplexes the higher frequency band into individual channels. It can break a signal into the equivalent of 24 analog voice grade and/or 56 Kbps digital channels.