摘要 |
An optical repeating path fault location system for a PCM optical transmission system which is composed of a backward transmission path and a forward transmission path respectively formed of separated optical fibers and having disposed therein a plurality of PCM optical regenerative repeaters at the same repeating positions for the transmission paths. For each of the transmission paths at each repeater position, there are provided a detector for extracting from each one of the transmission paths at least one of frequency signal components individually assigned to the repeaters to provide a detected output, and pulse generating means responsive to the detected output to generate a predetermined common test pattern pulse train for applying as an optical signal to the input portion of the corresponding repeater in each the other of the transmission paths. Repeater identify signals including the frequency signal components respectively assigned to the sequentially disposed PCM regenerative repeaters of each one of the transmission paths are sequentially transmitted from a signal transmitting station of each one of the transmission paths. Each the other of the transmission paths is monitored for a fault on the basis of the reception result of the test pattern pulse train received by the signal transmitting station via each the other of the transmission paths. |