摘要 |
Optical regenerative relay amplifier (102) have a function for monitoring strengths of optical signals from an optical fibers (101), and issuing optical signal trouble detection signal (AIS (Alarm Indication Signal)) for shutting down optical strengths in case that optical signal inputs are lost, and notifying the trouble, and optical ADMs (103) have a wavelength path selecting function, a wavelength path bundle function, and a wavelength path trouble or quality monitoring function in addition to an AIS issue function, and the optical cross-connect systems (104) have an AIS issue function, a function for monitoring a trouble or quality of optical signals every wavelength path, a wavelength path grooming function, and a wavelength path protection function, and the terminal stations (105) transmit and receive services by optical signals having predetermined wavelengths, and monitoring a trouble or quality of optical signals every wavelength path is conducted without depending on signal speed and format. <IMAGE> |