| 摘要 |
PURPOSE:To decrease the time required for switching a transmission system by providing a function that an optical transmitter-receiver of a slave system is used for the execution of transmission when a fault of an optical transmitter- receiver or a broken optical fiber takes place in a main transmission system and connecting two sets of the master and slave system optical transmitter- receivers to a same optical star coupler. CONSTITUTION:Optical transmitter-receivers are connected respectively to different ports of a same optical star coupler 6 via optical fibers 7, 8 (OF-A, OF-B). In the normal transmission, stations 1-3 use an optical transmitter-receiver 4 (TR-A) of the system A for the execution of transmission. When a fault of the transmission system A takes place in the station 1, a fault detection transmission system switching circuit 9 detects a fault generated in the transmission system A of its own station, performs the stop of the optical transmitter-receiver 4 (TR-A) of the system A and the changeover to an optical transmitter-receiver 4 (TR-B) of the system B. |
