Minimizing wavelength-conversion costs in WDM optical networks with p-cycle-based protection

Abstract

We study the configuration of preconfigured protection cycles (p-cycles) in survivable WDM optical mesh networks with partial wavelength conversion with 100% restorability guaranteed against any single failures. We consider the general case in which a p-cycle is allowed to use converters partially on the path. We formulate the problem as two integer linear programs, one for nonjoint and one for joint optimization. In the nonjoint optimization case, working paths are known before the protection configuration is processed. Then, p-cycles and wavelength converters are optimally determined. In the joint optimization case, working paths, p-cycles, and wavelength converters are jointly determined. The objective in both cases is to minimize the total cost of link capacity used by the working paths and the p-cycles as well as the cost of wavelength converters required for accommodation of a set of traffic demands. The proposed p-cycle configuration architectures take full advantage of converter sharing that reduces the network cost by requiring as few converters as possible. Our numerical results indicate that the proposed approaches outperform existing ones in terms of total network cost, total number of converters required, and maximum number of converters required at a node.