| 摘要 |
PURPOSE:To stop the output of an optical signal at a transmission side automatically at the interrupting of an input optical signal due to the fault of a transmission line. CONSTITUTION:The optical optical repeater 12 of an optical repeater 4 of the optical duplex transmission system monitors an input optical signal from a transmission line 6 and outputs monitoring information 103 such as input optical signal interruption. An optical repeater 103 repeater 13 inserts the monitoring information 103 to an output optical signal outputted to the transmission line 9 and transfers the result. The optical repeater 12 detects the monitoring information from the input optical signal when the input optical signal is not interrupted. When the monitoring information information detected by the optical repeater 12 is a signal representing the interruption of the input optical signal, the optical repeater 13 uses the monitoring information 103 to stop the transmission of the output optical signal. The operation is implemented similarly even in other optical repeater station 3 and optical terminal stations 1, 2. |
