In SDH optical fiber transmission system the transmission path system for change-over

摘要

PURPOSE: To switch the transmission lines while exerting no effect on the line service without disconnection by absorbing the delay amount of signals through two different directions. ;CONSTITUTION: In the VC path terminal generator at the transmission side, a multi-frame structure means makes up the multi frame for the NNI frame on the input data of J1 byte of the VC-3 at the transmission. In a section terminal generator 40 at the reception side, frame synchronizing circuits 43 and 44 establish multi-frame synchronization based on the input data of J1 byte, a control circuit 47 detects the phase difference of the NNI frame signal due to the two directions A and B. The generator 40 controls one of the elastic memories 45 and 46 to absorb the phase difference.;COPYRIGHT: (C)1993,JPO&Japio