2400 BITS PER SECOND DUPLEX MODEM USING THE FREQUENCY DIVISION TECHNIQUE STANDARDIZED FOR USE ON THE GENERAL SWITCHED TELEPHONE NETWORK AND ON POINT-TO-POINT 2-WIRE LEASED TELEPHONE-TYPE CIRCUITS
Introduction These modems are intended for use on connections on the GSTN and on point-to-point 2-wire leased telephonetype circuits (see Note). The principal characteristics of these modems are as follows: a) duplex mode of operation on the GSTN and point-to-point leased circuits@ b) channel separation by frequency division@ c) quadrature amplitude modulation for each channel with synchronous line transmission at 600 baud (nominal)@ d) inclusion of a scrambler@ e) inclusion of an adaptive equalizer and a compromise equalizer@ f) inclusion of test facilities@ g) data signalling rates of: 2400 bit/s synchronous@ 2400 bit/s start-stop@ 1200 bit/s synchronous@ 1200 bit/s start-stop@ h) it is compatible with a V.22 modem operating in Modes i) or ii) at the 1200 bit/s signalling rate and includes automatic bit rate recognition. Note - In certain countries the use of such modems over the GSTN may not be allowed.