A Study On AODV Routing Algorithm For Wireless Sensor Networks

With rapid development of mobile communication, internet and communication technology continues to bring forth the new through the old one, the mobile users’ demands are increasing more and more. It shows that the mobile internet era is approaching quietly. The new challenges have proposed with the integrating of embedded technology, micro-system technology and wireless access technology standard. What’s more, it also makes WSN (wireless sensor networks) as an important and hot issue among researchers for its simple, flexible networking structure, which is integrated with sensors, communications, computing technology. As we know, WSN is derived from traditional Ad-hoc network, considering the routing algorithm needing to adapt its application of the actual situation, a variety of WSN’s routing algorithms are proposed.Each node in the wireless sensor network is both as host and router. Through adapting the multi-hop network structure, data can be delivered from neighbor nodes until reaching the destination. It makes the communication between the nodes not rely on switching with fixed nodes and reduces the possibility of congestion. As a result, the network performance improved. The paper is discussed typical characteristics and applications of WSN’s routing algorithm firstly, and then analyzed the most popular routing algorithms-----AODV (Ad hoc on demand distance vector routing) protocol’s performance, which is compared with others in several aspects, such as network architecture, throughput, topological changing frequency in some specific application environment. During this process, the metric of routing decision is mainly considered.Here, a new routing decision metric is given to replace the minimum hop routing method. That’s because when using hop-count as metric usually ignores the link status, which may cause some destinations to be unreachable. Even if the best route is a minimum hop-count route, in a dense network there may be many routers of the same minimum length, with varying qualities. The random choice made by most minimum hop-count metrics is not likely to select the best, particularly as the network grows and the number of possible paths between a given pair increase. So in this paper, a new module called "ETX" metric is added to modify the original wireless networks’. It can fix the problem through the calculation of sending routing messages forwarding detection to measure the success rate of communication link during given time which can help to indicate the link route decision metric. It’s conducted a series of simulations using NS2to compare the performance of AODV and new protocol. Experimental results show that, new protocol is better than the former one in the area of high throughput and it maintains the good performance of time delay. Moreover, with the adaptive characteristics of AODV algorithm, the new protocol is suitable for large-scale networks. After the routing algorithm simulation tests, it is demonstrated that the proposed algorithm basically achieves the design goals of wireless sensor network routing algorithm.