Stored Program Controlled Network: Overview

Two major trends in the North American telecommunications network today are the evolution to an Integrated Services Digital Network (ISDN) and the Stored Program Controlled (SPC) Network, which is an important component of the ISDN. The first is a product of the digital revolution and is driven Dy the fact that digital technology is increasingly becoming the economic choice for conventional voice applications while, at the same time, being the driving force for a wide range of data applications. In contrast, the term SPC network is the label given to a quiet but profound revolution in network intelligence, which is expanding the potential of our telecommunication network for both voice and data applications. More specifically, the SPC network refers to the set of SPC switching systems which is interconnected by common-channel interoffice signaling (ccis). 1579 100 YEAR Fig. 1--Bell System intertoll circuits served by SPC.