Carrier Communication Terminals

Abstract

Development in power line carrier communication has for many years been guided by the assumption that a single communication path between the terminal stations of a power line would be all that is required. Even where two or three telephone circuits were found to be desirable at a later time, recourse was again had to single-channel telephone terminals, which were then connected in parallel to the input of the coupling circuits. These carrier terminals were designed exclusively for telephone conversation. When remote supervision and control entered the picture at some later date, the first carrier terminals built were again of the single-purpose type and their transmission band was chosen so as to fit into the allocation scheme established for the speech frequencies.