Coding of Speech at 8 kbit/s Using Conjugate-Structure Algebraic-Code-Excited Linear-Prediction (CS-ACELP) - General Aspects of Digital Transmission Systems Study Group 15; 39 pp
that pulse code modulation (PCM) multiplex equipments are already used in various countries, in
particular to provide a large number of short-distance telephone circuits on certain pairs in existing cables, and in order to minimize the number of differen