Four-wire TDM telephone exchange - has additional switching matrix with several switching groups each having access to other groups via four-wire link

摘要

The 4-wire TDM telephone exchange needs fewer switching matrices and fewer crosspoint switches. Connection lines are formed into groups each with a bus for both directions. The buses of a group are connected via an internal group switch. For connections between different groups the bus-bars of the individual groups form the input and output lines of a further switching matrix. This matrix has several switching groups each with a given number of connection groups. Each switching group also has access via TDM, 4-wire link lines to the other groups in this extra matrix or can be reached from these other groups.