Wavelength cross connect device, and wavelength cross connect method

A wavelength cross connect device comprising:

• a wavelength band switching unit and a wavelength cross connect (WXC) unit,
• wherein the wavelength band switching unit is configured to:
• receive a first plurality of wavelength multiplexed signal beams each having been transmitted in multiple bands in a plurality of optical transmission lines respectively, the plurality of optical transmission lines each including one or a plurality of optical fibers, the first plurality of wavelength multiplexed signal beams each including multiplexed optical signals of distinct wavelength bands;
• split each of the received first plurality of wavelength multiplexed signal beams into a predetermined number of wavelength multiplexed signal beams;
• generate a plurality of wavelength-band-converted wavelength multiplexed signal beams generated for each of the received first plurality of wavelength multiplexed signal beams by performing wavelength band conversion on each of the predetermined number of wavelength multiplexed signal beams to convert the optical signals of the distinct wavelength bands multiplexed in the wavelength multiplexed signal beam into optical signals of different wavelength bands;
• and
• output a second plurality of wavelength multiplexed signal beams each of which is selected from a predetermined one of the split first plurality of wavelength multiplexed signal beams and the plurality of wavelength-band-converted wavelength multiplexed signal beams generated from the predetermined number of wavelength multiplexed signal beams split from the predetermined one of the split first plurality of wavelength multiplexed signal beams,
• wherein the WXC unit comprises:
• a plurality of first input-side WSSes each configured to split a respective one of the second plurality of wavelength multiplexed signal beams into a third plurality of wavelength multiplexed signal beams;
• and
• a plurality of first output-side WSSes mesh-connected to the plurality of first input-side WSSes, and
• wherein the WXC unit is configured to input the third plurality of wavelength multiplexed signal beams split by each of the plurality of first input-side WSSes to the plurality of first output-side WSSes so as to reroute the second plurality of wavelength multiplexed signal beams to be output to output transmission lines.