Patent ID: 7088922

Claim:
A wavelength division multiplexing optical communication system for transmitting wavelength division multiplexed signal light in which optical signals of a plurality of bit rates at different wavelength arrangement spacing are arranged in a predetermined signal wavelength band, wherein when performing at least one of a demultiplexing process for demultiplexing wavelength division multiplexed signal light to generate a plurality of optical signals and a multiplexing process for multiplexing a plurality of optical signals to generate wavelength division multiplexed signal light, in accordance with a plurality of wavelength regions into which said signal wavelength band is divided on the basis of a wavelength width unit set according to a minimum wavelength arrangement spacing, said wavelength division multiplexing optical communication system comprising: a signal control section capable of setting a bandwidth of each optical signal to an integral multiple of said wavelength width unit, using optical switches controlled by a control circuit, wherein said signal control section sets said bandwidth of each of the optical signals of different bit rates so as to approximately coincide with wavelength arrangement spacing corresponding to each bit rate.