Space-division electronic telephone exchanges

Cross-points used in a space-division switching system must fulfil certain requirements in regard to transmission, signalling, control and economics. Several types of component have been proposed for this function and the paper discusses them in the light of these requirements. A description is given of the trunking and control of a spacedivision switching system consisting of line concentrators and a highusage switching network through which calls can be set up on a one-at-a-time basis. The cross-points used in such a system can be any of the types described, and some details are given of the operating conditions of dry-reed-relay cross-points.