The Study And Application Of Ant Colony Algorithm In The Field Of Routing Optimization

In recent decades, multimedia communication applications such as audio and video service are becoming more and more popular with the rapid development of computer network. The’best effort delivery’ mechanism in traditional network has shown emergency to meet requirements of these applications. Quality of service (QoS), as a new standard to evaluate the performance of network, seems to be the mainstream. Proper QoS routing algorithms are keys to guard requirements in QoS. As a result, a lot of researchers show their interests in QoS multicast routing problems. However, such questions are difficult to answer based on traditional algorithms, which calls on new approaches.As one of evolutionary algorithms, ant colony algorithm mimics behaviours of ants in the natural. It shows advantages on solving combinational optimization problems due to its features:positive feedback, robustness and parallelism. In addition, many scientists pay attention to this algorithm in the field of QoS multicast routing optimization (QMR). This essay is aimed to rise a new ant colony algorithm to solve QMR under multi-constrains.In this essay, all the work done can be divided into three parts:(1) Unicast routing analysis and mathematic model building. In this part, an advanced ant system is proposed to solve unicast routing optimization. Besides, this algorithm is the background of the following work.(2) Mathematic model rebuilding based on multicast routing and QoS constrains. The essay is main about constrains on delay and bandwidth. In this part, based on the previous algorithm, a new version of ant colony algorithm is proposed through new mechanisms of state transmission and pheromone update to solve QMR optimization.(3) Simulation results show that the new algorithm proposed in part two can find optimal solution quickly and has a good scalability.