Time-division multiplex switching network

A time-division multiplex switching network, comprising:

• a plurality of switching units, constructed as time stages, arranged in separate groups, and operable to chronologically and spatially assign time channels;
• a respective plurality of time-division multiplex lines for an incoming transmission direction connected to said switching units, such that the lines connected to a switching unit of one group are also connected to a corresponding switching unit in each other group;
• per switching unit group, a plurality of multiplexers equal in number to the number of switching units and each including a plurality of inputs, a plurality of normally-used outputs equal in number to the number of said incoming lines connected to a switching unit, and a plurality of normally-unused outputs, said inputs of each of said multiplexers divided into groups of equal number and each such group connected to a like number of outputs of said switching units such that each switching unit of a switching unit group is connected to each multiplexer assigned to that switching unit group;
• and
• a plurality of normally-open switches connected between at least a portion of said normally-used outputs and corresponding normally-used outputs and operated when the respective switching portion fails.