Ad Hoc网络基于寿命估算MMAS的QoS组播路由优化算法

QoS Multicast Routing Optimization Algorithm in Ad Hoc Networks Based on MMAS with Lifetime Estimation

Ad Hoc网络QoS组播路由问题的目标是在动态网络拓扑图里生成一棵连通源节点和一组目的节点的带约束的最小生成树,已经被证明为NP完全问题.蚁群算法作为一种基于计算智能的计算方法,已成为解决Ad Hoc网络QoS组播路由问题的新的潜在力量.针对Ad Hoc网络中基于蚁群算法的QoS组播路由算法存在网络开销大、早熟收敛和信息素更新规则设置不合理等问题,提出一种基于寿命估算MMAS的Ad Hoc网络QoS组播路由优化算法,因其具有较好的平衡局部搜索和全局搜索能力,收敛结果可接近全局最优.NS2平台仿真结果也证明该算法具有较高的数据包传输率和较低的端到端分组时延,性能指标有进一步提高.

The goal of QoS multicast routing problem in Ad Hoc network, which has been proved to be a NP complete problem,is to generate a constrained minimum spanning tree connecting source nodes and a group of destination nodes among the dynamic network topology. Based on computational intelligence algorithms as representation of heuristic search algorithrns lAnt colony algorithms have become a potential power for solving this problem. However, QoS multicast routing algorithms based on ant colony algorithms in Ad Hoc network are confronted with numerous difficulties such as the large cost,premature convergence and unreasonable the rule of up- dating pheromone. Therefore, this paper proposes a QoS multicast routing optimization algorithm based on MMAS with lifetime esti- mation （ MMAS_LE } in Ad Hoc network, which is capable of balancing local search and global search and converging to the global optimum. Stimulation results on NS2 show that the proposed algorithm has a high delivery ratio and a low end-to-end delay of packet transmission, and further improves the performance index.