Patent ID: 8121477

Claim:
An optical node apparatus comprising: pa input-side wavelength mux/demux elements that are capable of receiving wavelength division multiplexed frame signal light input from pa input transmission paths and wavelength division demultiplexing and outputting the signal light, the number pa being one or greater; a switch module comprising: input ends, the number of the input ends being equal to pa times a maximum accommodating number of the wavelength division multiplexing of the wavelength division multiplexed frame signal light; and output ends, the number of the output ends being equal to pb times the number of the maximum accommodating number of the wavelength division multiplexing, pb being at least two; wherein each frame signal light that is wavelength division demultiplexed by an input-side wavelength mux/demux element is received at a corresponding input end, and each frame signal light that is received at the input end is output from one of the output ends which is related to each wavelength and is coupled to one of the pb output transmission paths, the number pb is at least two; pb output-side wavelength mux/demux elements that are capable of wavelength division multiplexing frame signal light for an output transmission path in the switch module for each of the output transmission paths; a reference light source that monitors and controls the switch module, the reference light source being capable of outputting reference light having a wavelength bandwidth that covers a demultiplexing resolution at the input-side wavelength mux/demux elements and the output-side wavelength mux/demux elements, and each of the pa input-side wavelength mux/demux elements comprises at least two first ports and at least two second ports, one of the first ports included in each input-side wavelength mux/demux element is coupled to the input transmission path, the other of the first ports is coupled to the reference light source, and each second port is coupled to each of the input ends of the switch module.