避免路由断裂的优化AODV路由协议

移动自组网(MANET)中，节点的移动容易引起链路失效，传统的按需距离矢量(AODV)路由算法的本地修复机制局限于在链路断裂后进行，如果修复失败或者过慢，可能导致缓存的数据包丢失。针对这一问题，提出一种避免路由断裂的优化AODV路由算法ARB-AODV，该算法首先对即将断裂的链路进行预测，然后计算有关节点的相对稳定度，将稳定性较高的节点插入即将断裂的链路中，以消除节点的边缘效应来避免路由断裂。在NS-2平台下采用随机路点移动模型(RWM)和恒定比特率(CBR)数据源进行实验，在节点的移动速度大于10m/s时，ARB-AODV算法的分组投递率保持在80%以上，其平均端到端时延比AODV算法降低了40%，归一化路由开销比AODV算法降低了15%。仿真结果表明，ARB-AODV优于AODV，能有效提高网络性能。

Optimized AODV routing protocol to avoid route breaks

In Mobile Ad Hoc Network (MANET), the movements of nodes are liable to cause link failures, while the local repair in the classic Ad Hoc On-demand Distance Vector (AODV) routing algorithm is performed only after the link breaks, which has some limitations and may result in the cached data packet loss when the repair process fails or goes on too slowly. In order to solve this problem, an optimized AODV routing algorithm named ARB-AODV was proposed, which can avoid route breaks. In ARB-AODV algorithm, the link which seemed to break was predicted and the stability degrees of the nodes' neighbors were calculated. Then the node with the highest stability was added to the weak link to eliminate the edge effect of nodes and avoid route breaks. Experiments were conducted on NS-2 platform using Random Waypoint Mobility Model (RWM) and Constant Bit Rate (CBR) data. When the nodes moved at a speed higher than 10m/s, the packet delivery ratio of ARB-AODV algorithm maintained at 80% or even higher, the average end-to-end delay declined up to 40% and the overhead of normalized routing declined up to 15% compared with AODV. The simulation results show that ARB-AODV outperforms AODV, and it can effectively improve network performance.