Patent ID: 11870497
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 10:
11. An optical transmission method comprising:
a local light transmission step of generating a plurality of local lights having different wavelengths, selecting, from among the plurality of generated local lights having different wavelengths, a local light having a wavelength that is closest to the wavelength of a received optical signal, and transmitting the selected local light to a coherent receiver;
a splitting step of splitting the received optical signal and transmitting the received optical signal to the coherent receiver via a first path; and
a transmission step of receiving the received optical signal via a second path, splitting the received optical signal into different paths according to wavelengths by using a wavelength multiplexer/demultiplexer, and causing a local light to be transmitted in the local light transmission step, the local light having a frequency that corresponds to a path in which the optical signal is included.