QoS Multicast Routing Algorithm Research Based On Multi-restraint

In recent years,along with the rapid developments of network,the"best-effort"services can not satisfy the users'demands proposed in transferring business flow. Especially Internet is rapidly developed and the number of nodes is increasing at exponent level toward the giant capacity,high speed and multimedia. Many new applications have appeared on internet,particularly multimedia application with high-bandwidth demand. It requires a mass of transmission of audio and video which take high bandwidth,such as video on demand,network meetings. How to guarantee the quality of service has already become the significant content and the hotspot in recently research domain of the network. We can know that routing algorithm is vital to complement QoS in network in recent years from study. And the ant colony algorithm is one of the best algorithms for solving the multicast routing problem with multi-QoS constraint.On these several issues proposed,this paper gives introduces and discuss.In the beginning,this paper introduced the basic backgrounds of QoS multicast routing and summarized the multicast routing algorithms briefly,then analyzed several classical QoS routing algorithms in details,and proposed several issues existing in the study of QoS multicast routing like Shrotest Path Tree algorithm-SPT,Minimal Spanning Tree algorithm,Steiner Tree algorithm,and gives a prospect of its development in the end.This paper analyzes the basic theory and model of ACA; introduces the features of ACA and its research state ; selects some key parameters'value of ACA by simulations.The slow convergence and stagnation behavior are the main drawback of basic ACA,so In allusion to the flaws of ant colony algorithm,a bi-directional ant colony algorithm for solving the problem has been posed in this paper,and the update strategy of the pheromone in the ant colony algorithm has been improved. Simulation results demonstrate that the algorithm can converge to the approximately or best solution fast,and perform well as the size of network increasing.The traditional QoS routing problem researches assume that the network information is precise,while in practical situation the growing network size makes it increasingly difficult to gather up-to-date state information in a dynamic environment and so the full knowledge on network parameters is typically unavailable. In order to solve this problem,this paper integrate ant colony algorithm and bandwidth based on the non-precise information and proposes a new way of solving the probability. Simulation results demonstrate that the algorithm can achieved good results such as the mission success rate.