The minimum coincidence routing approach in wavelength-routed optical WDM networks

Management is a critical issue in optical networks. Highly impacting in management, routing in optical networks, is often decoupled into both the path selection and the wavelength assignment problems. In the former, shortest path based approaches are often applied to compute paths. Although such approaches offer advantages in terms of network loading, they are restricted by the fact, that routes are selected without taking into account parameters pertaining to any explicit and desired service guarantees. Thus, the wavelength assignment process may assign a non-optimal wavelength with respect to incoming traffic requirements and any associated quality of service specifications. This paper addresses the lightpath selection problem by proposing a novel route selection scheme where routes are determined based upon the twin criteria of minimizing the number of hops and balancing the network load, resulting in a reduction in both network congestion and blocking probability.