Optical communication device that transmits WDM signal and transmission control method

A transmission control method of processing a WDM (wavelength division multiplexing) signal using an optical communication device provided at a node between a first node and a second node in a WDM transmission system that uses a first wavelength band and a second wavelength band different from the first wavelength band, wherein

• the optical communication device comprises:
• a wavelength filter configured to extract a first WDM signal allocated in the first wavelength band and a second WDM signal allocated in the second wavelength band from a reception WDM signal received from the first node;
• a first wavelength selective switch configured to process the first WDM signal extracted by the wavelength filter;
• a second wavelength selective switch configured to process the second WDM signal extracted by the wavelength filter;
• a third wavelength selective switch;
• a wavelength converter configured to convert wavelengths from the second wavelength band to a third wavelength band;
• a fourth wavelength selective switch configured to process an optical signal in the first wavelength band;
• a fifth wavelength selective switch configured to process an optical signal in the second wavelength band;
• and
• a combiner configured to combine an optical signal output from the fourth wavelength selective switch and an optical signal output from the fifth wavelength selective switch,
• the transmission control method comprising:
• guiding an optical signal, that is branched from the first WDM signal by the first wavelength selective switch, to the third wavelength selective switch;
• guiding a remaining optical signal, that is not branched from the first WDM signal, to the fourth wavelength selective switch;
• guiding an optical signal, that is branched from the second WDM signal by the second wavelength selective switch, to the third wavelength selective switch via the wavelength converter;
• guiding a remaining optical signal, that is not branched from the second WDM signal, to the fifth wavelength selective switch;
• and
• the third wavelength selective switch guides the optical signal branched from the first WDM signal and the optical signal branched from the second WDM signal to an access network connected to the optical communication device.