Apparatus and Equipment
Chester W. Lonnquist, Joseph C. Manganello, Robert S. Skinner, Michael T. Skubiak, D. J. Wadsworth · Bell System Technical Journal · 1969
The No. 2 ESS achieves a standardized modular design that is easy to engineer, manufacture, install, operate, maintain, and administer. The use of much existing standard ESS hardware combined with thin film integrated circuits, plug-in growth units, and judicious interframe connectors, has contributed to the development of an economically attractive system for the small central office market.