Research On The Fault-Tolerant Of Dynamic Source Routing Protocol In Wireless Ad Hoc Networks

A mobile ad hoc network is a collection of wireless mobile nodes forming a temporary network without the use of any existing network infrastructure or centralized administration. This network routing technology is one of the key technologies to ensure the quality of the wireless network. However for the reason that its network node positions are not fixed, and mobile nodes speed and direction are unpredictable, the routing have frequently led to the failure. The failure of routing will show poor performance in wireless network. So how to design a fault-tolerant routing protocol to fit the current situation changes and adjustments will be one of the hot spots.Dynamic source routing (DSR) protocol is a very popular self-organizing wireless network routing protocol. As it is a reaction routing protocols and network topology is not update in period time, DSR have some problem in dealing with the network wrong that due to routing failure. Therefore, how to tolerate the fault of the DSR protocol path routing failure, and ensure higher performance of wireless network in frequent changes in network topology will be the focus of this paper.This paper introduced the principle of DSR protocol, including routing found, routing maintain and the content of packet header. Through analyzing the performance changes of wireless networks in the conditions of mobile nodes, we discovered the implications arising from the failure of the routing. We present two optimizing strategy including information feedback strategy and routing prediction strategy in DSR protocol. Information feedback strategy can improve the ability of routing found by using the principle of data packets passing the redundant information. Routing prediction strategy is a pro-active mechanism of routing maintenance. Through estimating the survival time by location-based information of the adjacent nodes and mobility information, it can reduce the routing maintenance time by noticing advance node to initiate the routing replacement. Because of the tolerance of routing failure, it guarantees wireless network performance under the conditions of frequent changes in topology.In this paper, NS-2 network simulation software was used to realize two strategies and to make performance analysis. The experiment results indicated that the performance of optimized DSR protocol had been improved significantly in throughput, the average end-to-end delay and packet loss rate, and in the mobile node conditions, the wireless network would tolerant the fault of invalid routing by using timely routing replacement.