| 摘要 |
PROBLEM TO BE SOLVED: To prevent deterioration in a transmission characteristic. SOLUTION: In the NB-WDM system, a WDM TERM station 1 and at least two IN-LINE AMP stations 2, 3 are connected in series for the transmission of an optical signal. In this case, the WDM TERM station 1 provides wavelength number information in a management information format of a wavelength number control signal sent in the NB-WDM system. Furthermore, at least the two IN-LINE AMP stations 2, 3 have alarm/control management UNITs 15a, 15b managing the wavelength number information and the two IN-LINE AMP stations 2,3 monitor the presence of occurrence of a fault in an optical signal based on the wavelength number information. Thus, transfer of erroneous information due to a fault of a preceding station is prevented, an output of an optical amplifier is kept proper and the deterioration in the transmission characteristic is prevented. |
