| 摘要 |
PURPOSE:To effectively utilize the area of a wavelength for maintenance by transmitting service information besides a call by using an optical signal in the area of the wavelength for maintenance which is not used excepting for the case of measuring the characteristic of an optical fiber. CONSTITUTION:A switch circuit 27 successively switches connection with a characteristic measuring device 25 in order to investigate the characteristic of each optical fiber 12 similarly to conventional and normally, however, a service supplying device 31 is connected to the optical fiber 12 which is not connected to the characteristic measuring device 25. Therefore, when any light pulse having the wavelength for maintenance is not transmitting for measuring the characteristic, the service supplying signal is transmitted from the service supplying device 31 through the route of the switch circuit 27, optical fiber 13, photocoupler 21, optical fiber 23, photocoupler 22 and optical fiber 17 to a service receiver 33. |
