ITU-T V.26 TER PDF

Introduction

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.