Patent ID: 7917033

Claim:
A wavelength-multiplexing optical transmission system comprising: a transponder that outputs an optical signal with a predetermined optical wavelength; a wavelength-multiplexing optical transmission apparatus including a wavelength multiplexing unit that multiplexes wavelengths of optical signals input from the transponder into an optical signal, and a wavelength demultiplexing unit that demultiplexes wavelengths of a multiplexed optical signal and outputs demultiplexed optical signals to the transponder; and a connection cable for connecting the transponder and the wavelength-multiplexing optical transmission apparatus, wherein the wavelength-multiplexing optical transmission apparatus further includes a detecting unit that determines whether an optical level of one of the optical signals input from the transponder reaches a predetermined value or not; an optical-wavelength-information storing unit that stores therein optical wavelength information on an optical wavelength of an optical signal to be output from the transponder, and an optical-wavelength-information transmitting unit that transmits the optical wavelength information stored in the optical-wavelength-information storing unit to the transponder via the connection cable, when the detecting unit determines that the optical level of one of the optical signals input from the transponder does not reach the predetermined value, and the transponder includes an optical-wavelength control unit that controls an optical wavelength of an optical signal to be input to the wavelength multiplexing unit based on the optical wavelength information received from the optical-wavelength-information transmitting unit.