Research On QoS Multicast Routing Algorithm And Simulation

The recent advances in the high-speed communication networks have enabled the network to provide more and more multi-media applications, such as audio/video conference, distributed simulation, multi-user game, distributed database...etc, which have made the multicast a necessity. However, the problem is that if multicast is realized only by sending packet copies to the destinations respectively, the network resources will be wasted greatly while the processing ability of network nodes will be affected dramatically, making network congestion more serious. Therefore, setting up an efficient multicast routing algorithm is essential to the realization of multicast communication in that it is the algorithms determines the construction of multicast tree, along which the packets could be transmitted with high speed.The present study is designed to investigate the multicast routing and the other relevant key problems. Following the introduction to some basic knowledge of multicast communication and its practical problems remained to be solved, the paper presents some typical algorithms such as the multicast routing algorithm, the Steiner tree theory and its relevant algorithm, the genetic algorithm as well as the ant algorithm. Based on the detailed discussion about two key algorithms, the genetic algorithm and the ant algorithm, combination of genetic algorithm and ant algorithm (GAAA), is finally set up and realized by adopting C++ language. The simulation results suggest that the new algorithm is more efficient and more economical than the genetic algorithm and the ant algorithm.This thesis consists of six main charpters:Charpter 1 briefly demonstrates the development of multicast routing, the present situations of the related studies, the objectives, significances and sources of the study, some typical routing algorithms as well as some knowledge about QoS, also introducing the source and meaning for this article.Charpter 2 studies QoS constrained Steiner tree Problem, introducing serval mainly heuristic algorithms, discussing multicast theory that supporting QoS.Charpter 3 recommends the development history of genetic algorithm, and including characteristic, advantage and disadvantage. We also give the basic step, introduce hybridgenetic algorithm, some details have yet to be discussed about soluting the constraint QoS with genetic algorithm.Charpter 4 demonstrates the origin, development, basic principles and procedures of ant algorithm. Ant algorithm is a general purpose algorithm inspired by the study of the behavior of ant colonies. This part Then it studies two typical ACOs , namely ACO and MMAX, carefully.Charpter 5 is the key part of the whole paper. It puts forward GAAA algorithm,a combination of genetic algorithm and ant algorithm for QoS multicast routing, it adopts genetic algorithm to solve and to give information pheromone to distribute and make use of its ability of quickness and stochastic on a globally searching. At the same time, it gives the well solution make use of the characteristics of ant algorithm converges on optimization pass information pherom one accumulation and renew. The simulation result show that the algorithm is valid and effective.Charpter 6 summarizes the major findings, presents the limitations of the present study and puts forward some suggestions for the future studies.This paper is supported by National Natural Science Foundation of China (project NO,60172035).