DSR路由协议的优化

Optimization for Dynamic Source Routing in Mobile ad Hoc Networks

DSR是一种按需式路由协议,它分为路由发现和路由维护两部分。但是这个协议有一些不合理的地方:它抛弃了固定网路由协议的所有成果,重新提出了一套全新的路由办法;它采用了洪泛法来发现路由:它的路由维护采用发现下游机不可达时原路返回出错信息的办法,这耽误了时间,而且遇到单向路径时不能工作。本文提出继承固定网频繁交换路由信息的特点,有机会就交换路由信息;由中间节点参与错误路由处理;及利用距离信息优化路由发现等。和DSR路由协议相比,优化后的DSR具有路由查找和维护控制开销小、包传送效率高等特点。该文证明了优化后的DSR协议的正确性,并通过实验仿真分析证实了其有效性。

Routing protocol of AD HOC has been an issue of AD HOC research.but it still seems no one is so good that it can fit all situations and be approbated by people. DSR is a simple, and effective one on demand. It consists of two parts. Part of route finding and part of route maintenance. However, the protocol has some disadvantages. It was created for AD HOC that inherits nothing from Internet route protocol disregarding its having been used effectively for more than ten years. It uses flooding as the way to find route and when a node can not find next hop node it will report the converse. This will result in waste of time and will not work when falling across single way net. Some methods were produced in the paper to solve the problems : 1. Under the condition of supporting sleep nodes should exchange information of route as possible as they can ; 2. To find route according to distance between source node and destination node'3.Intermediate node should be charged with the mistake of losing next hop node. Compared with the original DSR, the changed DSR costs less route finding and controlling spending and possesses higher packet delivery fraction. Optimized DSR was proved and performances of DSR and optimized DSR were simulated, analyzed and compared with nsz in the paper.