Routing and wavelength assignment in optical mesh networks with wavelength conversion

In a dynamic lightpath allocation scheme, a lightpath is established on-demand, in response to a request for communication. The optimization techniques traditionally used in determining an optimum routing and wavelength assignment (RWA) in a robust WDM network are quite complex, requiring a significant amount of time. In this paper we introduce a new integer linear program (ILP) formulation for dynamic wavelength allocation in survivable, wavelength convertible WDM networks, using dedicated and shared protection. We also propose a simple and efficient heuristic. Networks with no wavelength conversion can be viewed as a special case of the heuristic. The ILPs are suitable for small to moderate sized networks. They have also been used to validate the performance of the heuristic, by comparing its results to optimal solutions generated by the ILPs. For very large or highly congested networks, the heuristic can be used