Automatic Toll Switching Systems

This paper deals primarily with the major switching centers required for the nationwide automatic switching plan. These are called Control Switching Points (CSP's) and are supplied with switching equipment endowed with great versatility and a high order of mechanical intelligence. M r . Pilliod's paper 1 explains how for purposes of circuit layout and routing, they are assigned different rankings as follows, starting with the lowest ranking: Primary Outlets (PO's), Sectional Centers (SC's), Regional Centers (RC's) and one National Center (NC). Substantially the same equipment is to be provided for all of these centers so t h a t they all will have inherently the same capabilities. T h e y will, however, differ greatly in size. In the United States and Canada, as now envisaged, there will be somewhat under 100 of these CSP's. T h e system which Hell Telephone Laboratories developed for use at C S P ' s and which embodies all of the features required at those important 860 AUTOMATIC TOLL S W I T C H I N G SYSTEMS