网格和组播树结合的QoS路由

Combination of Mesh and Multicast Tree QoS Routing

由于Ad Hoc网络的自身特性,QoS组播路由成为当前主要研究热点之一.ACO算法能够解决这种自适应路由问题.基于网格结构的组播路由健壮性好但传输效率低,基于树结构的则刚好相反.针对以上问题,提出一种基于蚁群算法的按需组播路由协议.首先在传统的基于网格的组播路由协议建立的网格上利用蚁群算法建立一个组播树,以保证组播数据分组的转发率,并通过人工蚂蚁信息素的更新规则满足一定的QoS要求,同时原来的网格结构当树结构被破坏时可以用作备用路径.最后,仿真结果表明,该协议在平均端到端时延和路由开销方面要优于基于网格的协议,如ODMRP,同时在数据分组转发率方面也有不错的表现.

QOS-aware multicast routing is one of the most major issues in Ad Hoc networks since it＇s features like frequent topology changes, ACO algorithm can definitely address this dynamic scenarios. The conventional multicast routing protocols are categorized into two broad groups. Mesh-based approaches are robust and inefficient, tree-based approaches are exact opposite. This paper pro- posed a new ant colony optimization based on-demand multicast routing protocol, abbreviated ACODM, in which a tree structure is built by utilizing ant colony optimization from the previous mesh structure to ensure the effective delivery of multicast data packets, and to satisfy certain QoS requirements through artificial ant pheromone update rules which take into consideration the energy, delay and hops. Meanwhile, the original mesh structure may be used as an auxiliary one in case of tree structure failure. Finally, the simu- lation results show that ACODM outperforms the mesh-based protocol in average end-to-end delay and routing overhead, and has a pretty well performance in data packet delivering rate.