改进的蚁群算法与网络QoS组播路由研究

Modified Ant-Colony Algorithm and Its Application in QoS Multicast Routing

组播路由和网络服务质量(Qo S),是当前Internet研究的两个重要应用课题。Qo S组播路由是寻找满足特定Qo S约束的一棵最优组播树,是一个典型的NPC完全多目标优化问题。针对传统蚁群算法,首次引入"蚁王"概念,使其能对路径寻优过程进行存储、排序和指导,从而使群体搜索过程更加协调有序。蚁群信息素的变化则采用精英信息素矩阵更新策略,以加快算法的收敛速度。相关仿真实验证明,这种改进的算法在解决Qo S组播问题时,能够获得比基本蚁群算法明显优越的收敛性能。

Multicast routing and QoS（Quality of Service） are two important topics of present Internet research. QoS multicast routing, focused to select an optimized multicast routing tree with sufficient resources to meet the requirement of customers, is a typical NPC complete multi-objective optimization problem. The traditional ant-colony algorithm is modified with the introduction of a “queen”concept, thus to help in storage, sorting, and selecting of paths. Meanwhile, the elitist pheromone matrix is used as a strategy to update related pheromone, so as to speed up convergence of the algorithm. Simulation with Matlab indicates that, this new method could achieve much better performance than the basic ant-colony algorithm.