Modelos e algoritmos para o projeto de redes ópticas WDM

Abstract

This work focuses on the Routing Problem and the Problem of Routing andWavelength Assignment (RWA), both are among the main problems in WDM optical networks. Tey take the network survivability. A protection ad ded to the network in order to make it more reliable in case of failures. Initially, two models are presented for the Routing Problem. The difference between them is basically the element that receives the protection, links or network nodes. In order to add new metrics and features to the models, more objective functions are inserted transforming them into multi-objective. More specifically the models contain three criteria to be minimized, the first being the number of links used in the transportation, the second is the number of rejected requests and the third is the load balancing in the network. It is a problem of high complexity and this work proposes a multi-objective genetic algorithm based on a meta-heuristics NSGA-II. For the RWA problem two models are also proposed. The first attempt is to solve the problem of RWA applying a protection on the links of the network. In the second, a protection is defined over nodes. Because it is a difficult problem due to complexity, a genetic algorithm is developed to treat the RWA problem with protection on the links and the comparisons between the solutions obtained via heuristic and CPLEX show that the solutions are very close. The results show the quality of the algorithm proposed. Finally a third model is proposed for the multi-objective RWA problem, with the goal of adding new features and metrics to the mono-objective model.