移动自组织网(mobile ad hoc networks,MANET)的多跳的无线连接、动态拓扑和有限的带宽等特征,给其路由协议带来了很多挑战.当多跳路径失效时,路由协议需要对其进行修复.已有的修复机制需要很多的开销和很长的端到端时延.在此修复机制的基础上,提出了一种新的路由局部修复算法,将修复尽量限制在断链的局部范围内,以减少对链路断裂的反应时间和降低路由维护的开销,而且不用考虑失效链路在整个路由上的相对位置,都可以对其进行修复,提高了处理失效链路的能力,有利于提高MANET的可扩展性.仿真表明,这种新的路由局部修复算法明显地提高了网络多方面的性能.
Multi-hop wireless connectivity, frequently changing network topology and limited bandwidth are main characteristics of mobile ad hoc networks, which pose lots of challenges to routing protocols of such networks. If multi-hop route fails, the routing protocol should maintain it. The previous route repair mechanism causes high control overhead and long packet delay. The problem worsens when mobility is high and many real-time applications do not tolerate such long delays. In broken route, only nodes near the broken links may need to be substituted and the rest of nodes can be retained on the route. In this paper, a new idea about local route repair which limits the repair vicinity of the broken links is proposed to decrease the reaction time of route breakage and the overhead of route maintenance. This is desirable to solve the problem with the least cost in terms of both bandwidth and time. Furthermore, the approach can repair failure links without taking into account of their relative position on the whole path. It improves obviously the ability of dealing with failure links and scalability properties of ad hoc networks. Simulations show that the improved routing protocol results in significant performance improvement, such as packet delivery ratio and end-to-end packet delay.