Control circuit for PCM TDM async. integrated telephone exchanges - uses one exchange to synchronise other to reduce number of speech buffers

摘要

The control circuit, for PCM TDM a sync. integrated telephone exchanges, reduces the number of buffers or speech memories in the input circuitry by operating both transmission directions in synchronism with one exchange (Vstl). One of the input circuits of the neighbouring exchange is used as a synchronising group (SG) for all read and write operations in time with its own exchange. The other input circuits are operated as a sychronous groups (AG), without buffers, for the read and write operations of their own exchanges. These other circuits are synchronised with the circuits of the first exchange. Transit time equalisation between transmission directions takes place only in the synchronous group.