Patent ID: 6525850
Filing Date: 2003-02-25
Classification: H04J,H04Q

Abstract:
A method for propagating a data payload from an input network element to an output network element in a wavelength division multiplexing (WDM) network composed of a plurality of network elements, the data payload having a given format and protocol, the method comprising the steps ofgenerating and storing a local routing look-up table in each of the network elements, each local routing table determining alternative local routes through the associated one of the network elements, adding a header to the data payload prior to inputting the data payload to the input network element to produce an optical signal, the header having a format and protocol and being indicative of the local route through each of the network elements for the data payload and the header, the format and protocol of the data payload being independent of the format and protocol of the header, detecting the header at the network elements to produce a switch control signal as the data payload and header propagate through the WDM network, selecting one of the local routes for routing the optical signal through each of the network elements as determined by looking up the switch control signal in the corresponding local routing table, and routing the optical signal through the network elements in correspondence to the selected route, wherein the header is composed of one or more header signals each being conveyed by a distinct sub-carrier frequency and arranged so that the highest detectable sub-carrier frequency corresponds to an active header signal, the plurality of sub-carrier frequencies occupying a frequency band above the data payload, the step of detecting including the steps of concurrently measuring the header signals to produce a header selection signal, selecting the active header signal as conveyed by the highest detectable sub-carrier frequency under control of the header selection signal, and processing the active header signal to obtain the switch control signal for routing the optical signal.