Patent ID: 7620323

Claim:
A node for use in a WDM optical communication system that includes a plurality of nodes interconnected by communication links, the node comprising: a first plurality of transponders each generating and/or receiving an information-bearing optical signal at a different channel wavelength from one another; an optical coupling arrangement transferring the channel wavelengths between a link connected to the node and the first plurality of transponders, said arrangement being adaptable to reconfigure its operational state to selectively direct different ones of the channel wavelengths from the link to different ones of the transponders without disturbing the optical path through the node traversed by any other channel wavelengths, wherein said optical coupling arrangement includes a tunable coupling arrangement for selectively transferring the different ones of the channel wavelengths from the link to the first plurality of transponders and a passive coupling arrangement for directing the channel wavelengths from transponders to the link, said optical coupling arrangement further including a reconfigurable optical switch having at least three ports, said reconfigurable optical switch being adaptable to reconfigure its operational state to receive at a plurality of the ports any of the channel wavelengths at which the first plurality of transponders operate and direct said channel wavelengths to any remaining ones of the ports of the optical switch; and a communications and configuration arrangement transferring data identifying the respective channel wavelengths at which the transponders operate from the transponders to the optical coupling arrangement and, in response to the transferred data, reconfiguring the operational state of the optical coupling arrangement.