| 摘要 |
PURPOSE:To orientate the faulty point of optical fiber without using any additional measuring device, by setting previously the synchronized reference time at the both end offices of an optical fiber communication and then measuring at the both end offices the time from the reference time a fault detection of the optical signal level. CONSTITUTION:The input signal Q1 is supplied to the light transmission part 34 at the end office A, and theoptical signal reaches the end office B via the optical coupler 35, optical cable 31 plus optical repeaters 32 and 33. Then the signal Q1 is delivered from the light reception part 37 through the optical coupler 36. In the same way, the signal Q2 supplied to the light transmission part 38 of the end office B is delivered from the light reception part 39 of the office A. When the synchronous signal is supplied to the part 34 at the office A and at the time t1, the synchronous signal is supplied directly to the time counting part 43 and also sent to the office B to be separated at the synchronous signal separating part 41 and then supplied to the time counter 42. Thus a synchronous reference time is set. The occurrence of fault is detected at the fault detecting parts 44 and 45, and a difference of time to the reference time is counted at the time counting parts 43 and 42. In this way, the fault point (x) is orientated without using any additional measuring device. |
