| 摘要 |
In a passive optical network in which a plurality of subscriber equipment units 20 are connected to a central office equipment unit 18 via a star coupler, non-faulty subscriber equipment units can be quickly recovered from a communication failure caused by a faulty subscriber equipment unit. A control signal of wavelength # 2 is wavelength-division multiplexed with a main signal of wavelength # 1 . Using the control signal of wavelength # 2 , the subscriber equipment units 20 are selectively deactivated from the central office equipment unit 18 and, based on the recovery state during the deactivation process, the faulty subscriber equipment unit or units are located and deactivated. Alternatively, the output of each subscriber equipment unit 20 is monitored and if an abnormality is detected its output is stopped. |
