Flexible waveband routing optical networks

A novel coarse granular routing scheme for elastic optical networks is proposed in this paper together with a node architecture and network design algorithm. The proposed scheme bundles optical paths to be routed together and each bundle of paths, named flexible waveband, is routed as an entity. Path bundling is done by a small port count wavelength-selective switch (WSS) while flexible waveband routing is done by the other optical switches, i.e., two stage routing. The proposed network design algorithm resolves the routing and frequency slot assignment problem while considering specific constraints imposed by the routing scheme. Numerical experiments on several topologies confirm that the routing performance degradation caused by the coarse granular routing is small while the number of WSSs is substantially reduced.