Patent ID: 6233074
Filing Date: 2001-05-15
Classification: H04J

Abstract:
An optical add drop mpdule (OADM) connected to am ingress optical input and an egress optical output, comprising:a 1 to N wave division multiplexing (WDM) demultiplexor coupled to said ingress optical input, said WDM demultiplexor outputting N optical channels each said channel corresponding to a different wavelength;a N channel optical coupler connected to said N optical channels output of said WDM demultiplexor, said optical coupler outputting N optical pass through channels and N optical drop channels;an N channel optical receiver adapted to receive said N optical drop channels output by said optical coupler, said optical receiver for converting optical input signals to electrical output signals;an N channel optical switch adapted to receive said N pass through channels output from said optical coupler and N optical add channels, each channel outputting, in accordance with a channel control signal, either said optical pass through signal or said optical add signal;an N channel optical transmitter adapted to receive N electrical add channels and to output said N optical add channels, said optical transmitter for converting electrical input signals to optical output signals;an N to 1 WDM multiplexer coupled to said N output optical channels from said optical switch and operative to combine said N output optical channels into a single single channel for transmission over said egress optical output;a controller adapted to generate said N channel control signals input to said N optical switches;wherein each channel of said OADM is operative to drop an optical signal received via said ingress input while simultaneously optically coupling said optical signal to said egress optical output; andwherein each channel participates in optical multicast connections whereby an optical signal generated at a single source node is dropped at multiple destinations while simultaneously being passed optically to a downstream node.