No. 10A Remote Switching System: Physical design

The physical design objectives of No. 10A Remote Switching System (RSS) were to package the system into as compact a design as possible to allow for easy adaptation to both CDO and pair gain applications, to maintain an economic advantage over other alternatives, and to provide ESS service requirements. The interconnection technology was chosen to permit a 1024-line system to be contained in a single frame and to maximize the use of least-expensive interconnection techniques. Circuit partitioning and frame engineering rules were devised to minimize equipment growth, which minimizes installation cost, and to maximize plug-in apparatus growth, which keeps more costly circuit equipage at a minimum. The single (−48 volt) power requirement and low-current drain [less than the step-by-step (s×s) equivalent] allowed minimum and often reuseable battery plant requirements. The small system size resulted in reuse of existing buildings or use of a small portable modular building. The circuit partitioning and system design was implemented to ensure ESS central office service objectives. Because of the short time between manufacture and service, burn-in of electronic circuitry was instituted to minimize the impact of infant mortality on early service. Low cost was also carried into the sparing philosophy by using predicated performance data in conjunction with accepted centralized spare stocking strategies to identify a minimum spare stock which achieved required service objectives. Each aspect of the No. 10A RSS physical design taken together provides a low-cost, small-size, highly reliable electronic switch which will further extend the market coverage of electronic switching systems.