To provide a method of monitoring a cause of deterioration in quality of an optical signal that can contribute to the realizing of an economical, highly reliable optical network capable of containing a multimedia service having a large communication capacity per a service and variety of signal formats and signal bit rates, and to provide a device therefor.
A cause of deterioration in quality of an optical signal is estimated by using a measured value of a wave deterioration parameter obtained by a process of estimation of the wave deterioration parameter and a measured value of an optical signal-to-noise ratio parameter obtained by a process of estimation of the optical signal-to-noise ratio parameter. By estimating to prescribe both of the wave deterioration parameter and the optical signal-to-noise ratio parameter, it is judged whether the main cause of the quality deterioration of the optical signal is of the deterioration of the optical signal-to-noise ratio or the deterioration of the wave.
TAKARA HIDEHIKO
UCHIYAMA KENTARO
Kazuo Abe