Recent new features for the no. 5 crossbar switching system

THE NUMBER 5 crossbar switching system was described by Korn and by Ferguson1 in 1950, just a year and a half after the first installation was placed in service at Media, Pa. These authors mentioned the growing need “ ... for a dial system which would better meet the telephone switching requirements for areas on the outskirts of metropolitan cities and at the same time care for medium-to-large sized offices in other areas.” Since that time, the basic switching plan of this system has proved to be so flexible and adaptable that it is finding an ever-expanding application in many new combinations of switching requirements. After a brief review of the basic switching plan described in more detail in the previous article, this paper will cover some of the new features since added to the system.