Circuit configuration for telecommunication switching systems, in particular PCM time division multiplex telephone switching systems with a central switching network and peripheral sub-switching networks connected to it

Claim 1

A circuit configuration for centrally-controlled telephone switching installations comprising: a central switching network together with a central processor; a plurality of peripheral line groups equipped with one sub-switching network each for the external connection of connection and/or subscriber lines and with one peripheral control unit; wherein: the line groups are assigned to each other in pairs and mutually represent partner line groups; in each of these line group pairs, internal terminals of the sub-switching network associated with each partner is selectively switchably connected to the terminals of its central switching network and, via link lines, to the terminals of the central switching network and the internal terminals of the sub-switching network of the other partner; each of the line units of the line groups in a partner pair are alternatively switchably connected to the external terminals of their sub-switching network and, via internal lines, to the external terminals of the sub-switching network of the partner line group; whereupon for connections which extend via a line unit of a first partner of a pair of line groups and via the internal lines to the sub-switching network of the second line group of the pair, appropriate switching signal processing as well as sub-switching network setting may be carried out by the control unit of the second line group of the pair; the connection circuits of the network each support a message channel and a signal channel; in preparation for shunting a lien unit to a partner's sub-switching network via an internal line, each of the two control units outputs connection data which, with respect to all message path sub-connections existing via its particular sub-switching network, indicates which external sub-switching network connections are connected with which internal sub-switching network connections to a particular partner control unit and, in conjunction with such received connection data, establishes individual message path sub-connections via the sub-switching network of its own line group, and, specifically, between such sub-switching network connections with which the internal lines of the particular partner line group are connectable through shunting a line unit, and such sub-switching network connections which through this shunting the link lines of the particular partner line group are to be connected via the external sub-switching network connections and message path sub-connection; the internal lines carry only a message channel and within one rerouting phase are all changed over without delay in contrast to the signaling paths which lead within each line group to their control unit and only those connection paths which are free are switched over from their control unit to the partner line group as well as those connections paths via which connections between subscribers are completely through-connected due to the particular called party having answered.