The Telephone Channel in a Global Communications System

The nominal 4-kc telephone channel is by far the most dominant parameter of contemporary telecommunication networks. It is, directly or otherwise, underwritten by a world-wide investment of the order of fifty billion dollars. The engineering of present and future global communication networks must therefore provide for working with and into such channels, concomitantly with finding avenues out of their limitations as a device for partitioning and and utilizing communications space. This paper is a characterization of the telephone channel to a first order of approximation-its loss, phase and noise characteristics and some related operational factors.