Crossbar Tandem as a Long Distance Switching System
01 January 1956
The crossbar tandem switching system, originally designed for switching between local dial offices, will now play an important role in nationwide dialing. New features are now available or are being developed that will permit this system to switch all types of traffic. As a result, crossbar tandem offices will have widespread use at many of the important switching centers of the nationwide switching network. This paper briefly reviews the crossbar tandem switching system and its application for local switching, followed by discussion of the general aspects of the nationwide switching plan and of the major new features required to adapt crossbar tandem to this plan. 1 CROSSBAR TANDEM OFFICES USED FOR LOCAL SWITCHING Crossbar tandem offices are now used in many of the large metropolitan areas throughout the country for interconnecting all t} pes of local dial offices. In these applications they perform three major functions. Basically, they permit economies in trunking by combining small amounts of r