Communications switching—From operators to photonics

Very soon after Alexander Graham Bell invented the telephone, it became obvious that it would be impractical to extend wires from every telephone to all other telephones. To conserve copper and dollars, wires had to converge on central points where individual telephone-to-telephone connections would be made. In this paper we will describe many significant changes in the Bell System network from the early part of this century when manual switching systems predominated to the stored program controlled electronic switching network which existed in 1984 at the time of the Bell System divestiture; as well as the current thrusts in digital switching, packet switching, distributed control, and research in broad-band and optical switching technology.