Electronic Systems and Equipment for Evolving Loop Plant

This paper discusses a French plan for enhanced subscriber service, and some of the systems and equipment that will meet these goals on existing loop plant. Since 1972, the French PTT has been installing digital central offices at the national, regional, and local levels. Coverage is expected to reach 10000000 lines by 1985, so that when integrated services can be offered, the nation will be ready to take advantage of them. A PTT-sponsored program, directed toward all-digital subscriber loops, has revealed four principal phases. The first of these is already in progress: both digital and analog pair-gain systems are now being installed on existing loop plant. Soon to come is the second Phase: residential subscribers will be able to obtain two-channel subscribercarrier installations, with the carrier channel supporting data services, independent of the voice service on the same loop plant. Integrated Services Digital Networks, the third phase, should stretch the French loop plant to maximum capacity. When the demand for broad-band services overrides the capabilities of the existing copper pair plant, fiber optics cable installation will be fully planned and implemented as the fourth phase.