Many-Objective Evolutionary Algorithms for Multicast Routing with Quality of Service Problem

In order to guarantee a proper end-to-end communication in computer networks, many applications impose Quality of Service (QoS) requirements. In QoS routing, multiple conflicting objectives are optimized simultaneously. On the other hand, multicasting (i.e. sending data to multiple destinations) in its simplest form is a computationally difficult problem, which becomes more challenging when QoS requirements are considered. Previous works have investigated the use of multi-objective evolutionary algorithms (MOEAs) in the multicast routing with QoS problem under a Pareto-dominance approach. In particular, the so-called SPEA2 algorithm has provided good results in problem formulations involving up to four objectives. However, it has been recognized that for higher-dimension problems the convergence of MOEAs can decline substantially. In this work, we propose a model for routing based on the many-objectives algorithm MEAMT (multi-objective evolutionary algorithms with many tables), aiming at better dealing with the difficulty faced by state-of-the-art routing methods when solving for higherdimensional formulations. We present the new model for multicast routing based on MEAMT, as well as report experiments on a comparison with SPEA2-based routing in formulations involving 4, 5 and 6 objectives over several problem instances with different topologies and sizes. The results indicate that the new routing model overcomes SPEA2 in most cases, specially when solving for higher dimensional problems in routing.