A Novel Efficient Design of Survivable WDM Mesh Networks

Abstract

The design of survivable WDM mesh networksbased on p-cycles has been extensively studied. However,most of studies only deal with a single link failure ratherthan node failure. In this paper, we develop a new scalableand efficient design method for computing node-protectingp-cycles in order to ensure network survivability. Theperformance of our new proposed design method makes anobvious improvement 20% in capacity redundancy overthat of the previous one.The conventional design methods formulate the problemof p-cycle design as an Integer Linear Program (ILP). Tosolve the ILP, the prerequisite is to a priori enumeratedall possible p-cycle candidates. For a large network, theresulting ILP may be intractable as the huge number ofcycles may exist. We propose a new design and solutionmethod based on large scale optimization tools, namelyColumn Generation (CG), where p-cycle candidates aregenerated on-line when needed. The main advantage of ourCG-based method is that no p-cycles are a-priori off-lineenumerated; the generation of the promising set of p-cyclesis embedded in the optimization process.Extensive experiments have been conducted for comparison.Experimental results show that our new proposedmethod outperforms the previous method in terms of capacityefficiency.