A Routing and Network Dimensioning Strategy to reduce Wavelength Continuity Conflicts in All-Optical Networks

Due to the high computational complexity of exact methods (e.g., integer programming) for routing and wavelength assigment in optical networks, it is beneficial to decompose the problem into a routing task and a wavelength allocation task. However, by this decomposition it is not necessarily possible to obtain a valid wavelength assignment for a given routing because of wavelength continuity constraints in the network. This paper proposes an extension of the routing and network dimensioning subproblem that facilitates a subsequent wavelength assignment in the absence of wavelength converters. The extension anticipates wavelength continuity conflicts by limiting the maximum number of traversing lightpaths at each node. Such a limitation is derived from a lower bound on the number of conflicts, given a routing and network configuration. Preliminary computational experiments indicate that our approach can reduce the number of lightpath blockings significantly.