Multicast Protection in WDM Networks based on Multiobjective Evolutionary Algorithms

The huge bandwidth exploited in optical fibers and the ability to handle multiple simultaneous transmissions on the same fiber due to the WDM technology, have made the problem of protection, multicast routing and wavelength allocation (MPRWA) critical for the success of point-to-multipoint applications. In order to maintain the quality of service required by these applications, the network faces the restriction of rapid recovery in cases of failure. Also, it must minimize the different costs that this entails, and prioritize requests in case of not having the necessary resources for recovery. In this context, this work deals with the design of the main multicast route and its protection, with quality of protection (QoP) levels. For this reason, two protection schemes have been addressed: dualtree based and biconnected-subgraph based. To achieve this, competitive evolutionary techniques are applied; where the total number of links used, the number of wavelength converters, the number of splitter nodes, and the number of destinations served and protected are objective functions simultaneously optimized in a Pareto context. The experimental tests were carried out on different network topologies and multicast demands, considering the hypervolume as a Pareto quality measure. The results suggest that the subgraph-based strategy is more promising, obtaining better results than the protection based on dual-tree.