Research On Routing And Localization Scheme In Wireless Sensor Networks

Wireless sensor networks obtains the physical information of the objective world by collecting,processing and transmitting the information in the monitoring area,t.It has very strong application prospects in industry,medical treatment,agriculture,environment,military and smart home industries.In the important technology of wireless sensor networks,the design of an efficient,energy-efficient and reliable routing strategy which is the key to prolonging the network life cycle and improving the overall performance of the network.Wireless sensor networks has a large monitoring range and the nodes are usually randomly deployed.Therefore,designing a simple and accurate localization algorithm has become the core of node localization technology.Based on the existing research results,this paper focuses on the research of routing protocol and node location technology in wireless sensor networks.The main innovative work of this thesis includes:1.A large-scale routing optimization algorithm for wireless sensor networks is proposed.In LEACH protocol,cluster heads are randomly selected,without considering the communication overhead and residual energy of cluster heads.The proposed optimization algorithm divides the whole network coverage area into several equal-width layers and clusters within the layers.After the high level cluster head nodes collect the data,it transfers to cluster head nodes in the lower layer,and transfers the data to the base station through the lowest cluster head nodes.In the cluster closest to the base station,In the cluster closest to the base station,if the cluster member nodes are farther from the cluster head node than the base station,they will directly transmit data to the base station instead of the cluster head node.The experimental results show that,compared with LEACH protocol,the proposed algorithm has lower energy overhead for communication from member node to cluster head and cluster head to base station,and effectively prolongs the lifetime of the whole network.2.An energy optimization method for wireless sensor networks based on dynamic cluster head competition mechanism is proposed.This optimization method takes into account the main factors affecting network energy consumption,such as distance from sink nodes,distance between nodes and residual energy of nodes.The concepts of competition time and competition radius are proposed.The optimal cluster head is the result of competition by multiple factors.The non-uniform clustering of nodes is achieved by using distance to reduce energy consumption of nodes;For the obtained node clusters,the generation tree was proposed and established,and the cluster head was guided to complete the optimal path selection and power adjustment,and the data transmission to sink was completed in the most energy saving way.Through the simulation experiment,it is proved that this algorithm can improve the energy balance of sensor network significantly,effectively avoid the appearance of energy void and extend the service life of the network.3.A routing optimization algorithm based on OLSR for mobile wireless sensor networks is proposed.Firstly,an objective function of data routing is established,which combines the advantages of least squares support vector machine(LSSVM)algorithm and particle swarm optimization(PSO)algorithm.The residual energy of nodes is predicted online by a combined model,and the data is transmitted through the route with the least energy consumption.The experimental results show that the algorithm can quickly find the route with the least complex overhead,improve the reliability of data transmission,and reduce the data transmission delay.4.An network lifecycle optimization algorithm under the assistance of mobile relays is proposed.A weighted AODV algorithm is proposed to establish a routing tree which considers the residual energy of the node and the distance to the mobile relay node.The movement of the relay node is based on the OMRC algorithm,and it does not only consider the energy of the nodes moving and transmitting data.At the same time,the residual energy of the node is considered.The data transmission is divided into two cases,single data flow and multi data stream transmission.The result shows that this method can reduce energy consumption and prolong network life cycle.5.An improved node location algorithm based on DV-Hop is proposed.The algorithm replaces the average hop distance of beacon nodes with the average hop distance of the whole network,calculates and utilizes the estimated and real distance errors of all beacon nodes in DV-Hop algorithm,thus obtains the error of the average distance of each hop,and then optimizes the positioning process by using particle swarm optimization algorithm,and finally obtains the positioning results of the nodes.The experimental results show that the improved algorithm can improve the positioning accuracy of sensor nodes,and the results are satisfactory.