Electronic switching system software structure considering virtualizing technique and software components

Abstract

AbstractThe stored‐program control system presently forms the main‐stream of the switching control system because of the flexibility in function modifications, compared with the wired‐logic hardware. One of the problems which has manifested recently is the large number of steps of the software modifications, which accompany with the modifications of the switching system architecture and the additions of functions. One of the major reasons for the large number of modification steps is the traditional modularisation, where the switching system architecture and the signaling systems are assumed to be retained. Because of this assumption, the modifications have to be made at various scattered points in the software systems, or have to be made at unexpected points, thereby increasing the number of steps in the modifications. This paper aims at improving the versatility of the software, and describes the modular breakdown, where the modification is localized by making the switching system architecture and the signaling system implicit and virtualized. By the same idea as in the hardware architecture, the software component technique is realized, where the program‐unit is subdivided into a set of units depending on the starting conditions of the programs and a set of units not depending on the starting conditions, and the module is composed by combining those two sets of units. By an example, it is shown that the proposed software architecture is useful.