Circuit arrangement for centrally controlled time division multiplex telecommunication switching systems, particularly PCM-telephone switching systems with line trunk groups connected to a switching matrix

摘要

Line trunk groups coupled to a double central switching matrix by way of two PCM lines and including sub-switching matrix and group control units are allocated to one another in pairs. Prepared for stand- by service switch-over by the central switching matrix and the processor are subscriber and trunk lines within each line trunk group pair, which are connected to the sub-switching matrix of a first line trunk group and are switchable to that of a second line trunk group, such that their group control unit also assumes the control functions. The processor going into service with the stand-by switch-over is connected with the group control units of all first line trunk groups via its central switching matrix, while all switching service continues with those of all second line trunk groups. Connection data of all existing connections are stored in all group control units. Each of the first group control units requests these data from the corresponding second group control units which are thereupon transmitted and stored, and thereafter retrieved by the processor going into stand-by service and employed for the establishment of corresponding connections via the central switching matrix and first sub-switching matrices, whereupon subscriber and trunk lines within each line trunk group are switched over from the first sub- switching matrix to the second sub-switching matrix without interruption of connections.