A Systematic Design Procedure for Modular Stored-Program Telephone Switch Control Organizations

To overcome many difficulties besetting the design of a cost-effective stored-program telephone switch control, this paper proposes a systematic three-step approach: 1) selection from twelve basic subclasses of a software organization satisfying flexibility, reliability, and speed-of-service constraints; 2) estimation of program size and processing load assuming a rudimentary processor architecture; and 3) determination of an optimal stored-program-wired-logic boundary and a minimum cost processor architecture. The last step is simplified by using a quantitative criterion called speed-size ratio.