Multi-stage time connection network

Claim 1

A path finding system for a time division multiplex communication network for providing switching paths for time division multiplex signals transmitted therethrough, comprising: first and second identical multi-stage connection networks, each including an input stage, an intermediate stage, and an output stage, the input stage of each connection network comprising p input time switches having n incoming and m outgoing network lines, the intermediate stage of each connection network comprising m intermediate time switches with two p inputs and q outputs, and the output stage of each connection network comprising q output switches with m inputs and n outgoing network lines, each network line including a plurality of time channels and the switches having the same internal time division switching arrangement, each input time switch of one network being connected to respective inputs of the intermediate time switches of that network and to respective inputs of the intermediate time switches of the other network, each intermediate time switch being connected by means of an intermediate network line with the respective inputs of the output time switches of the network; central memory means, coupled to the intermediate stages of said first and second connection networks, for storing the busy or free condition of all the time channels of the incoming and outgoing network lines of each time switch in said intermediate stages; and access means, coupled between said central memory means and said intermediate stages, for reading into said memory means the condition of each intermediate time switch and for writing in each intermediate time switch the busy or free condition of each time channel in the incoming and outgoing network lines; and wherein said central memory means includes individual memory portions for said first and second connection networks.