Speech and signalling switching equipment in the Highgate Wood electronic telephone exchange

System operation of a t.d.m. switched highways electronic telephone exchange

“…This overcomes side-tone and transmission problems which would otherwise occur if within-group connections used the same channel pulse. 10 Unlike conventional electro-mechanical common-control exchange systems there is no particular equipment, termed a register, dealing exclusively with an individual call. Signals received from the subscribers take the form of channel pulse trains on a common highway to the register equipment.…”