| 摘要 |
PROBLEM TO BE SOLVED: To automatically adjust the output levels of the respective wavelengths of a self-station side so that the input levels of the respective wavelengths in an opposite station become uniform. SOLUTION: An optical signal monitoring circuit 20 always monitors an optical signal from a photocoupler circuit 17 and outputs a variety of information on the respective wavelengths, the light levels of the respective wavelengths and SNR(signal to noise ratio) to a monitoring and controlling circuit 21 as monitoring information. The monitoring and controlling circuit 21 works and displays and processes monitoring information inputted form the light signal monitoring circuit 20, outputs in to the overhead bit insertion circuit 3 of respective transmitter parts 11, selects one of received light signal monitoring information inputted from the overhead bit separation circuits 7 of the respective transmitter parts 11, monitors the optical signal levels for the respective wavelengths in received light signal monitoring information and controls the output levels of respective optical amplifier circuits 14 so that the light levels for the respective wavelengths, which are monitored in an opposite station, become constant. |
