Patent ID: 7817918
Filing Date: 2010-10-19
Classification: H04J,H04Q

Abstract:
1. A method of transmitting information from a start node through a plurality of intermediate nodes to a target node in a wavelength division multiplex optical communications network, each node including a wavelength selective optical cross-connect, the method comprising the steps of: configuring the cross-connect at each of the start node and the target node with a plurality of switching matrices for switching wavelength channels, the cross-connect at each of the start node and the target node having only a single switching matrix being operative for switching a wavelength channel of each single wavelength, each single wavelength channel being switchable by only the respective said single switching matrix; applying two wavelength channels having two wavelengths that are different, but modulated with the same information, to different respective switching matrices of the cross-connect at the start node; transmitting the two applied wavelength channels with the different wavelengths via the plurality of nodes passing through different respective switching matrices of the target node; extracting the two transmitted wavelength channels from different respective switching matrices of the cross-connect at the target node; modifying the wavelength of at least one of the two wavelength channels at a cross-connect of one of the intermediate nodes; dividing the wavelengths transmissible in the optical network into at least two groups; and selecting the wavelengths of the at least two wavelength channels from different ones of the at least two groups, each wavelength modification of one of the two wavelength channels at the cross-connect of the one intermediate node occurring between the wavelengths of a same group.