一种基于缓存技术的改进型AODV路由协议

A Modified AODV Routing Protocol Based on Cache Technology

AODV路由协议是adhoc网络中一种典型的按需路由协议,但是当网络节点具有高移动性,网络拓扑变化频繁使得路由链路断开频繁时,按需路由协议包括AODV算法都缺乏鲁棒性,各个移动节点在发送数据包时需要不断发起路由请求。文章对AODV算法进行了详细分析,并利用路由缓存技术对AODV算法进行了改进。在缓存中建立了两条备用路由,当活动路由链路断开时,选取一条较好的备用路由作为活动路由。NS2仿真结果表明,这种带缓存功能的AODV算法能降低丢包率、时延,提高路由的稳健性,从而适应网络拓扑结构的频繁变化。

Various routing protocols are proposed for ad hoc network, especially the On- Demand Routing Protocols, such as AODV. However, all On Demand Routing Protocols, including AODV algorithm, always lack robustness when the route link breaks frequently because of the frequent top changes due to the high mobility of the nodes, which have to send the routing request frequently while they need to send data packets but have no route to destination. This paper first analyzes the AODV protocol in detail, and then proposes an modified scheme by using route cache. Several backup routes are built up so as to select one of them as active route when the active link breaks. The simulation results in NS2 show that the modified AODV protocol by using route cache technology can decrease packet-loss ratio, reduce the routing delay and raise the routing robustness. This modified AODV protocol is more adaptable to the frequent top structure change than original one.