Development of a Multichannel PAM Telephone Transmission System

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.