Circuit arrangement for extending telephone PABX systems

摘要

The circuit arrangement for extending telephone PABX systems essentially comprises a higher-order, matrix-shaped switching network (KFÜ) with full availability, to which a plurality of sub-systems (TA) can be connected. These sub-systems (TA) are PABX systems designed as satellite systems which are connected via intermediate transmission circuits (Zw-Ue-T) to intermediate transmission circuits (Zw-Ue-H) which are connected to the higher-order switching network (KFÜ). Along with this first type (V1) of connection, which exists during the call set-up stage only, there is also a second type (V2) of connection in which columns of the switching sub-networks (KFT) are directly connected to rows (ZÜ) of the higher-order switching network (KFÜ). This second type (V2) of connection is set up only at the end of dialling and remains set up for the entire duration of a call. <IMAGE>