The problem of designing a wavelength routed optical transport network without wavelength conversion at intermediate nodes is considered. A class of valid inequalities for wavelength routing and assignment is reported and is used to augment traditional network design formulations. The resulting network cost provides a lower bound on the cost of a network that permits wavelength routing. The resulting network is shown to be optimal for a majority of the problem instances tested and in those cases where it is not, a trial-and-error method is proposed that is able to find near-optimal solutions within relatively short period of time. This is achieved by developing efficient and effective heuristics that attempt to provide a feasible wavelength routing. Computational tests are reported on relatively larger problem sizes than have been reported in literature on the wavelength routing problem. 
Near optimal design of wavelength routed optical networks