TIMEEDIVISION MULTIPLEXXSIGNAL ACCESS SYSTEM

摘要

PURPOSE:To simplify the constitution of a change-over control circuit by removing a slip phenomenon by changing transmitting and receiving memories over synchronizing with one frame period of an intra-office timing signal in the preamble signal period of a time-division multiplex signal. CONSTITUTION:Transmitting memories IDSM-A and IDSM-B and receiving memories DDSM-A and DDSM-B storable with >= one frame of a time-division multiplex signal are provided; and signals from office extension HWLO-I are written and the contents of the other are sent to office extension HWLO-I. For each memory, those operations are repeatedly switched in sequence and this switching is carried out synchronizing with frame periods of the intra-office timing signal in the preamble signal period of the received time-division multiplex signal. As a result, the occurrence of a slip phenomenon caused by a difference in phase of the timing signal can be prevented.