Patent ID: 7308197
Filing Date: 2007-12-11
Classification: H04J

Abstract:
1. An expandable network element, comprising: a wavelength selective switch having a plurality of input ports and a plurality of output ports, each of said plurality of input ports being coupled to a respective one of a plurality of input optical communication paths, and each of said plurality of output ports being coupled to a respective one of a plurality of output optical communication paths; wherein one of said input optical communication paths carries an optical service channel; a plurality of optical splitters, each of said plurality of optical splitters being coupled to a respective one of said plurality of input optical communication paths; a plurality of optical demultiplexers, each of said plurality of optical demultiplexers being coupled to a respective one of said plurality of optical splitters, one of said plurality of optical demultiplexers having an input coupled to one of said plurality of optical splitters, a plurality of first outputs and a second output; wherein at least one of said plurality of optical demultiplexers comprises an optical splitter having an input and a plurality of outputs, and a plurality of tunable filters, each of which being coupled to a respective one of said plurality of outputs of said at least one of said plurality of optical demultiplexers; a plurality of optical receivers, each of said plurality of optical receivers being coupled to a corresponding one said plurality of first outputs, said second output being a supplemental output not coupled to any one of said plurality of optical receivers; an additional optical demultiplexer coupled to said input optical communication path, said additional optical demultiplexer being configured to select said optical service channel; and a control circuit coupled to said additional demultiplexer and said one of said plurality of optical demultiplexers, said control circuit being configured to control said tunable filters in response to said optical service channel.