Electronic exchange system. Part 1: Structure
T.H. Flowers · Proceedings of the Institution of Electrical Engineers · 1971
Continuing from another paper, the equipment for the structure of an electronic telephone exchange is described together with the reasons for the choices made. Analogue circuits are switched by p.a.m./t.d.m. (pulse-amplitude-modulation/time-division-multiplex) switches and p.c.m. (pulse-code-modulation) circuits by t.d.m. switches of the same kind. The use of t.d.m. switches profoundly influences the choice of processors for supervisory, signalling and other low-level functions, which, in turn, have some effect on the high-level common and unique common processors which are the subject of Pt. 2 of the paper.