The Research Of A Gradient-Based Self Adaptive Wireless Sensor Network Routing Protocol

In recent years,with the improvement of the micro electro mechanical systems technology and communications technology,sensor nodes are more and more miniaturizing and intelligent.WSNs have become a hot spot in the research of information field.In the large scale applications of WSNs,how to sense the physical information and transmit them to users efficiently using these small,energy constrained, low cost sensor nodes is the key issue to expand the capability for people to obtain information.So the study of wireless sensor network routing protocol is very important.Routing protocol in WSNs is responsible for the data sensed to deliver from source to destination,so the quality of routing protocols has significant impact on the efficiency and reliability of information transmission and the performance of the network.In large scale sensor networks,mostly random deployment,the uneven distribution of nodes can cause some nodes exhaust energy too early and then impairing the performance of the whole network obviously.Thus the design of routing protocols should not only consider the energy,bandwidth,but also the coverage problem caused by uneven distribution.In this thesis,we firstly study on characteristic of large scale sensor networks,and then give the problems of connection and coverage.Besides,some typical topology control protocols and routing protocols are introduced.We propose a gradient-based adaptive wireless sensor network routing protocol(GASRP).There are two parts of the protocol.(1) Sleeping Algorithm:the network life time is extended through detecting the redundant nodes which need to sleep periodically;(2) Multiple-metric Routing Algorithm Based on Gradient:in this algorithm link quality,residual energy and delay are all adopted as a routing measure to provide a high efficient routing policy,which will increase the overall robustness of the network.Subsequently,we analyze the performance of the proposed protocol in Network Simulator(NS2),and make a comparison on the performance with AODV protocol. The result of experiments indicates that the performance of routing algorithm proposed has been improved and sleeping mechanism has the adaptability to the requirement of the sensing coverage.Finally,we present the conclusion and future work.