Optimal nonuniform wavebanding in WDM mesh networks

Grouping together a set of consecutive wavelengths in a WDM network and switching them together as a single waveband could achieve savings in switching costs of an optical cross-connect. This technique is known as waveband switching. While previous work has focused on either uniform band sizes considering a single node or ring networks, in this paper we focus on optimizing the number of wavebands and their sizes for mesh topologies. We formulate a problem of optimizing the number of wavebands in a mesh network for a given set of lightpaths. The objective of the Band Minimization is to minimize the number of nonuniform wavebands in the network while satisfying the traffic requests. We formulate an integer-linear program, and propose efficient heuristics. Simulation results are presented to demonstrate the effectiveness of the proposed approaches. Our results show that the number of switching elements can be reduced by a large amount using waveband switching compared to wavelength switching.