Abstract: A switching arrangement for pulse code modulation (PCM) time division multiplex telecommunication switching system is described. The frame storages for incoming and outgoing directions of transmission as well as their address memories, and the crosspoint address memory form a memory unit. The frame storages are read-in in cyclic sequence and read out selectively and it is possible to transfer information from anyone of the frame storages to either the same PCM trunk or to the space division switching network. Thus, there is a possibility both for return switching to the same PCM trunk and for switching through other switching units in a time-space-space-time format.