Routing, Protection and Traffic Engineering in WDM All-Optical Networks

Overview & Synopsis

This thesis mainly focuses on all-optical lightpaths establishment. We consider all along the thesis optical networks with finite resources, that is with a given maximum amount of wavelengths per fiber. Both exact and approximate optimization techniques are considered. In a first step, we investigate the problem of routing and wavelength assignment (RWA) considering permanent lightpath demands (PLDs) and develop ILPs (Integer Linear Programs) for both the routing and the wavelength assignment sub-problems. This work is then extend to deal with two classes of traffic demands referred to as scheduled lightpath demands (SLDs) and random lightpath demands (RLDs). On one hand, SLDs are characterized by pre-known dates of arrival and life durations. They may correspond for instance to a set of long term lightpath establishments in order to provide Optical Virtual Private Network services. On the other hand, RLDs are characterized by random arrival and life duration processes. In a second step, we deal with the routing and spare capacity assignment (RSCA) problem. Once again ILPs and heuritics are proposed to deal with the RSCA problem for PLDs, SLDs and RLDs. Due to the wavelength continuity constraint, a new lightpath demand may be rejected. In a third step, we focus on the improvement of the lightpath demand rejection ratio by means of lightpath rerouting strategies. We have developed such strategies in order to minimize traffic disruption on already routed demands. For each step, we have developed multiple optimization tools which have been applied to a wide range of network sizes, topologies and traffic scenarios. Our conclusions are then drawn based on these results.