Research Of Multicast Routing Algorithms With QoS Constraint Based On IP Network

With fast development of network technologies, increase of network bandwidth and processing power makes the network provide more multimedia applications, and also makes the multicast communication that supports "one-to-many" or "many-to-many" become a necessary mode of multimedia services. A fundamental issue in multicast communication is how to determine an efficient multicast routing, and finding simple, effective and robust multicast routing algorithms. This is unsolved problem in network fields. In addition, many distributed multimedia applications have various demands on delay, delay variation, bandwidth and packet loss, which requires current network to transmit real-time multimedia information with these quality-of-service (QoS) constraints. So, as an indispensable component in a QoS-centric network architecture, research on multicast routing algorithms based on IP QoS constraint becomes an important part and hotspot issue of network research fields.This paper researches the structure, typical service model and mechanism of QoS based on IP network, and introduces the key technology about it; Sets forth the principle of multicast routing based on IP QoS; And classifies the multicast routing algorithms with QoS constraints which have been put forward, especially analyzes Steiner Tree Algorithms with IP QoS constraint, emphasizes the least cost multicast routing with delay constraint problem and algorithms.The emphases of this paper rest with: analyzses the advantage and disadvantage of the traditional genetic algorithm, tuba search algorithm and stimulated annealing algorithm from convergence and the time and space complexity. And presents an improved Hygrid Genetic Algorithm: TSSAGMA, which combines the merit of tuba search algorithms and stimulated annealing algorithms. This algorithm ensures quick convergence in the last phase because it adopts the fitness function of stimulated annealing algorithm. On the other hand, by introducing crossover and mutation oftuba search algorithm, TSSAGMA can avoid precocity and can get a better solution. The simulative result illustrates TSSAGMA is better than traditional algorithms in solving the least cost multicast routing problem with delay constraint. In addition, by analyzing the simulated annealing algorithm and importing the conception of edges-switching and paths-switching, the paper presents two kinds of improved simulated annealing algorithms: SAESMA and SAPSMA, and proves the respective time complexity of them in theory.