DOUBLE LOOP TRANSMITTER

摘要

PURPOSE:To attain the relief of a synchronizing signal with simple control by allocating exclusively the synchronizing signal to time slots so that the synchronizing signal areas are not included in the same time slot number between two loops. CONSTITUTION:If the transmission is impossible with a digital transmission line L2, the OR information of switch memories SM1 and SM2 is outputted to a control signal CSM1. While a remote station extracts a frame header signal FH1 that obtained the OR between the synchronous and a synchronous section indicating signals of the line L2 out of the frame information on the line L2. Then a link memory has the same actuation as that of a normal mode. At the same time, the information stored to the memory SM2 can also be outputted to the signal CSM1 like the information of the memory SM1. Thus it is possible to relieve also the terminals connected to other digital transmission lines.