OPERATIONAL SOFTWARE FOR D10 ELECTRONIC SWITCHING SYSTEM.

The operational software for the D10 electronic switching system is an advanced real-time program system with a capacity of 200 kilowords. The program system consists of program groups for call processing, fault processing, administration processing, etc. To meet demands for various services peculiar to telephone switching, the programs are designed from the viewpoint of the state of calling and its transition. Also, since the hardware, except for the speech path, is highly centralized it is important to ensure its stability as a total system, and so such functions as fault detection, switching-over of system composition, restoration from faulty conditions, etc. are realozed in the programs. Programs dealing with communications between system and maintenance personnel are also available. When this program system is applied to subscriber line switching, its processing capacity is estimated at 4,000 Erlangs.