Optical access system and control signal superimposition method

An optical access system that performs communication using an optical signal on which a management control signal used for management and control is superimposed, the optical access system comprising:

• a subscriber device on a transmitting side and having an optical transmitter, where the optical transmitter is configured to generate an optical signal by superimposing a first management control signal on a main signal and transmits the generated optical signal;
• a management controller configured to output a second management control signal addressed to a communication counterpart of the subscriber device on a transmitting side, which is superimposed on the optical signal transmitted by the subscriber device on the transmitting side and which has a frequency band different from a frequency of the first management control signal superimposed on the optical signal and contains control content different from the first management control signal;
• and
• a control signal superimposer configured to superimpose the second management control signal output from the management controller on the optical signal.