Transmission system, transmission device, and transmission method

A transmission device comprising:

• an optical amplifier configured to amplify a first wavelength-multiplexed signal light in a first wavelength band;
• a multiplexer coupled to an output of the optical amplifier, the multiplexer being configured to multiplex the first wavelength-multiplexed signal light and a first supervisory control signal light ray that is a control signal for the first wavelength-multiplexed signal;
• and
• a transmission processing circuit coupled to an output of the multiplexer, the transmission processing circuit being configured to
• obtain the first wavelength-multiplexed signal light multiplexed with the first supervisory control signal light ray,
• demultiplex the first supervisory control signal light ray from the obtained first wavelength-multiplexed signal light to yield the demultiplexed first wavelength-multiplexed signal light from which the first supervisory control signal light ray has been removed,
• convert, to a second wavelength band different from the first wavelength band,
• the demultiplexed first wavelength-multiplexed signal light, and
• transmit a wavelength-multiplexed signal to another transmission device, the wavelength-multiplexed signal being obtained by multiplexing a second wavelength-multiplexed signal in the first wavelength band, a second supervisory control signal light ray that is a control signal for the second wavelength-multiplexed signal, the demultiplexed first wavelength-multiplexed signal in the second wavelength band, and the first supervisory control signal light ray demultiplexed from the obtained first wavelength-multiplexed signal light in the first wavelength band, the another transmission device including:
• a reception processing circuit configured to
• receive the wavelength-multiplexed signal,
• demultiplex, from the received wavelength-multiplexed, the first wavelength-multiplexed signal in the second wavelength band, the second wavelength-multiplexed signal in the first wavelength band, the first supervisory control signal light ray, and the second supervisory control signal light ray, and
• convert, from the second wavelength band to the first wavelength band, the demultiplexed first wavelength-multiplexed signal, and
• multiplex the demultiplexed first wavelength-multiplexed signal in the first wavelength band and the demultiplexed first supervisory control signal light ray;
• and
• a demultiplexer coupled to an output of the reception processing circuit, the demultiplexer being configured to demultiplex the first supervisory control signal light ray from the first wavelength-multiplexed signal output from the reception processing circuit, wherein
• the first supervisory control signal light ray and the second supervisory control signal light ray each have a wavelength in a wavelength band different from the first wavelength band and the second wavelength band.

A transmission method comprising:

• amplifying a first wavelength-multiplexed signal light in a first wavelength band;
• multiplexing the first wavelength-multiplexed signal light and a first supervisory control signal light ray that is a control signal for the first wavelength-multiplexed signal;
• demultiplexing the first supervisory control signal light ray from the first wavelength-multiplexed signal light multiplexed with the first supervisory control signal light ray to yield the demultiplexed first wavelength-multiplexed signal light from which the first supervisory control signal light ray has been removed;
• converting, to a second wavelength band different from the first wavelength band, the demultiplexed first wavelength-multiplexed signal light;
• and
• transmitting a wavelength-multiplexed signal to another transmission device, the wavelength-multiplexed signal being obtained by multiplexing a second wavelength-multiplexed signal in the first wavelength band, a second supervisory control signal light ray that is a control signal for the second wavelength-multiplexed signal, the demultiplexed first wavelength-multiplexed signal in the second wavelength band, and the first supervisory control signal light ray demultiplexed from the obtained first wavelength-multiplexed signal light in the first wavelength band, the another transmission device including:
• a reception processing circuit configured to
• receive the wavelength-multiplexed signal,
• demultiplex, from the received wavelength-multiplexed, the first wavelength-multiplexed signal in the second wavelength band, the second wavelength-multiplexed signal in the first wavelength band, the first supervisory control signal light ray, and the second supervisory control signal light ray, and
• convert, from the second wavelength band to the first wavelength band, the demultiplexed first wavelength-multiplexed signal, and
• multiplex the demultiplexed first wavelength-multiplexed signal in the first wavelength band and the demultiplexed first supervisory control signal light ray;
• and
• a demultiplexer coupled to an output of the reception processing circuit, the demultiplexer being configured to demultiplex the first supervisory control signal light ray from the first wavelength-multiplexed signal output from the reception processing circuit, wherein
• the first supervisory control signal light ray and the second supervisory control signal light ray each have a wavelength in a wavelength band different from the first wavelength band and the second wavelength band.