System of controlling wavelength division multiplexed optical amplifier and method thereof

A method of controlling degree of amplification and supervising operation of optical amplifying stages in an optical exchange system, using a supervision channel optical signal in an optical transmission system, the optical transmission system including an optical transmission path connected to the optical exchange system and the optical amplifying stages, the method comprising:

• (a) designating optical amplifying stages to be controlled and supervised by the optical exchange system, generating a supervision channel optical signal including the degree of amplification for respective optical amplifying stages and supervision requests for the respective optical amplifying stages, multiplexing the supervision channel optical signal and a data channel optical signal to produce a multiplexed optical signal, and transmitting the multiplexed optical signal;
• (b) extracting, at each optical amplifying stage, the supervision channel optical signal from the multiplexed optical signal and converting the supervision channel optical signal so extracted into an electrical signal;
• (c) amplifying, at each optical amplifying stage, the data channel optical signal by one of the degree of amplification set by the optical exchange system for the respective optical amplifying state and included in the supervision channel optical signal or by a degree of amplification set by the respective optical amplifying stage itself when the degree of amplification for the respective optical amplifying stage is not included in the supervision channel optical signal;
• (d) inserting, at each optical amplifying stage, state information of the respective optical amplifying stage into the electrical signal when the respective optical amplifying stage is designated in a request included in the supervision channel optical signal;
• (e) converting, at each optical amplifying stage, the electrical signal into a converted optical signal, multiplexing the converted optical signal with the data channel optical signal amplified by the respective optical amplifying stage to produce a new multiplexed optical signal, and outputting the new multiplexed optical signal;
• and
• (f) extracting, in the optical exchange system, the supervision channel optical signal from the new multiplexed optical signal, converting the supervision channel optical signal extracted at the optical exchange system into a second electrical signal, and supervising operation of the optical amplifying stages in response to the second electrical signal.