SYSTEM FOR SEARCHING IDLE SWITCHING TIME SLOTS DEFINING A SELECTED FOUR-WIRE COMMUNICATION CONNECTION THROUGH A SWITCHING NETWORK WORKING ON THE BASIS OF TIME AND SPACE-DIVISION

摘要

ABSTRACT:System for searching idle switching time slots defininga selected four-wire communication connection througha switching network working on the basis of time andspace-division.A control arrangement for controlling and coor-dinating the required switching operations in a switchingnetwork is designed among others to search idle switchingtime slots which can be used for a requested four-wirecommunication connection. Thereto a recording memoryis used for continuously recording for each time switchthe idle-busy condition of switching time slots.During the search for idle switching time slots for afour-wire communication connection which has to beestablished via separate time switches at the input ofthe network, at least one pair of idle locations inthe recording file which can be suitable for a four-wire communication connection that has to be establishedvia one and the same time switch is skipped and reservedbefore a pair of idle locations in this recording filerepresentative of the searched switching time slotsfor the requested connection that has to be establishedvia separate time switches, is seized. This createsthe possibility of making the chance of blocking forconnections that have to be established via separateinput time switches (external group connection) virtuallyequal to the chance of blocking for connections thathave to be established via one and the same input timeswitch of the network (internal group connections).