The Future of Digital Communications

The current global telecommunications plant, an estimated 50 billion dollar investment, is built around the 4-kc channel and frequency division multiplex (FDM). The characteristics of this 4-kc channel are uniquely suited to telephone communications at continental distances (mean of 2000 miles with a dynamic range varying from 200 to 6000 miles) and all but ignore predominately digital communications. The characteristics of the present plant also ignore the possibility of a high percentage of intercontinental connections (mean of 6000 miles and a dynamic range varying from 1500 to 15,000 miles). Intercontinental communication is not limited by feasibility, but by appropriate planning and generally poor signal quality, i.e., low signal-to-noise ratios for speech and high error rates for digital communication. This paper considers the characteristics of digital communications resulting from increases in intercontinental traffic, and indicates the effect of impact of these characteristics on future telecommunication networks.