TWO-WAY OPTICAL COMMUNICATION SYSTEM AND METHOD FOR SETTING ITS OPTICAL TRANSMISSION RECEPTION LEVEL

摘要

PROBLEM TO BE SOLVED: To keep transmission quality constant by easily and surely adjusting a level of an optical signal and correcting fluctuation in the level of the optical signal in real time. SOLUTION: A monitor controller 22 in a center station 1 monitors a transmission reception state of an outgoing optical transmitter 3 and an incoming optical receiver 6, sets an attenuation of an optical variable attenuator 19 to a specified value and a status monitor circuit 23 in a node optical transmitter 2 monitors an outgoing optical receiver 4 and an incoming optical transmitter 5 and sets an attenuation of an optical variable attenuator 10 to a specified value.