Development of a Multichannel PAM Telephone Transmission System
R. Scott, J. C. Perkins · IRE Transactions on Communications Systems · 1965
This paper outlines the design features, principles of operation, and performance characteristics of a voice transmission path employed in an electronic telephone switching system. The transmission path is two-wire, bidirectional, and incorporates PulseAmplitude Modulation (PAM) as a means of interconnecting the subscribers' line circuits. The system provides facility for 100 simultaneous conversations or "links" in the form of 100 discrete time positions. The techniques employed for supervising and signaling the subscriber's line are also described.