ITU-T - V.26 TER
2400 BITS PER SECOND DUPLEX MODEM USING THE ECHO CANCELLATION TECHNIQUE STANDARDIZED FOR USE ON THE GENERAL SWITCHED TELEPHONE NETWORK AND ON POINT-TO-POINT 2-WIRE LEASED TELEPHONE-TYPE CIRCUITS
|Publication Date:||1 November 1988|
This modem is intended for use on connections on the GSTN and on point-to-point 2-wire leased telephonetype circuits (see Note 1). Its principal characteristics are as follows:
a) duplex mode of operation on the GSTN and point-to-point leased circuits,
b) half-duplex mode of operation (optional) on the GSTN and point-to-point leased circuits (Note 2),
c) channel separation by echo cancellation,
d) differential phase-shift modulation for each channel with synchronous line transmission at 1200 baud (nominal),
e) inclusion of a scrambler,
f) inclusion of a compromise or adaptive equalizer,
g) inclusion of test facilities,
h) operation with data terminal equipment (DTE) in the following modes:
2400 bit/s synchronous,
1200 bit/s synchronous (fall-back rate),
2400 bit/s start stop (optional),
1200 bit/s start stop (optional) (fall-back rate),
i) inclusion of an operating sequence intended to allow interworking with 2-wire duplex 4800 bit/s modem (which modem is for further study).
Note 1 - In certain countries the use of such a modem over the GSTN may not be allowed.
Note 2 - When the optional half-duplex mode of operation is used, provisions in § 7 shall supersede provisions given elsewhere in this Recommendation.