Patent ID: 6757495
Filing Date: 2004-06-29
Classification: H04J,H04Q

Abstract:
A system for multicasting a data payload through an optical network composed of a plurality of nodes interconnected by links wherein a given one of the nodes multicasts over two outgoing links, the data payload having a given format and protocol, the system comprising:a label-switch controller on said optical network; a route generator coupled to said label-switch controller and configured for generating and storing a local routing look-up table in each of the nodes, each local look-up table listing local addresses for determining alternative local routes through each of the nodes; an adder coupled to said label-switch controller and configured for adding two headers to the data payload with each of the headers being embedded in the same wavelength as the data payload prior to inputting the data payload at an input one of the nodes to produce an optical signal, each of the headers having a format and protocol and conveying multicast information indicative a local route through the given node for the data payload and the headers, the format and protocol of the data payload being independent of the format and protocol of the headers; a switching device on said optical network which is configured for being controlled by the label-switching controller; a detector coupled to said switching device and configured for detecting the multicast information at the given one of the nodes to determine two switch control signals with reference to the multicast information as the data payload and the headers propagate through the optical network; an optical splitter configured for splitting the optical signal received by said switching device into two split optical signals; a selector coupled to said switching device and configured for selecting two local routes through the given one of the nodes in correspondence to the two switch control signals; an optical switch having input ports and output ports wherein one of the split optical signals couples to a first input port and the second of the split optical signals couples to a second input port, and wherein one of the outgoing links couples to a first output port and the second of the outgoing links couples to a second output port; and a switch controller, coupled to the optical switch and responsive to the two switch control signals, and configured for switching the optical switch in response to the multicast information to optically couple the first input port with the first output port and the second input port with the second output port; and wherein the headers are conveyed by a single sideband signal occupying a given frequency band above the data payload; an opto-electrical converter within said detector configured for converting the optical signal to detect the headers; a processor, coupled to opto-electrical converter, within said detector configured for processing the headers to detect the multicast information; and an optical notch filter configured for filtering the optical signal with a reflective part of the notch filter to delete the headers and recover the data payload, and means, coupled to the notch filter, for inserting new single sideband headers at the given frequency band into the optical signal in place of the deleted headers.