Patent ID: 6563614
Filing Date: 2003-05-13
Classification: H04B,H04J

Abstract:
An apparatus comprising:an optical signal controller configured to provide a monitoring signal from an optical signal in a plurality of sub-band signals at least one of which includes a plurality of optical signal channels, and control the characteristics of the optical signal based on the sub-band signal characteristics as provided by the monitoring signal; wherein said optical signal controller is configured to combine a compensating channel having a power based on the sub-band signal powers to control the characteristics of the optical signal; and wherein said controller includes: an optical distributor configured to provide the monitoring signal from an optical transmission fiber carrying the optical signal; and a sub-band demultiplexer configured to separate the monitoring signal and provide the plurality of sub-band signals to sub-band control loops, wherein each sub-band control loop includes: an optical to electrical converter configured to receive one of the sub-band signals and provide a sub-band input signal; a sub-band input comparator configured to compare the sub-band input signal power to a set point power level and provide a sub-band input error; a source controller configured to vary the optical power of a sub-band compensating channel provided by a sub-band compensating source in response to the sub-band input error; a multiplexer configured to combine the sub-band compensating channels from said control loops into a compensating channel; and, an optical combiner configured to combine the compensating channel with the optical signal channels in said transmission fiber.