Research On Routing Protocol Of Wireless Sensor Network Based On Energy And Distance

The wireless sensor network is composed of a large number of sensor nodes in a self-organizing and multi-hop manner.All sensor nodes cooperate in the area to collecte,process and transmit data.However,sensor nodes are usually battery-powered,and they are often be located in an uncontrollable area.It is unable to replace the battery.If the node's energy is exhausted,the network system will crash.Therefore,achieving low consumption and high utilization of node's energy and prolonging lifetime of the network is an important problem.First,this paper studies wireless sensor networks and their routing protocols,gives the system structure of the wireless sensor network and the characteristics and classifications of the routing protocol,and lists some typical wireless sensor network routing protocols.Secondly,put the focus on the analyzing and improving of LEACH protocol.The main contents and achievements are follows:1.To solve the problem of cluster head selecting in LEACH protocol,this paper optimizes cluster head selecting process by considering energy and distance of nodes.The improved algorithm considers the mean and standard deviation of the residual energy and the distance between the node and base station as a weight parmeter introduced into the original threshold to form a new threshold.It makes nodes who is closer to the base station and has more residual energy more likely to be chosen as cluster heads.2.To solve the problem of uneven clustering,this paper optimizes clustering process by considering energy and distance of cluster heads.In the clustering process,it adds a clustering-threshold which is calculated based on the energy of the cluster heads and the distance between the node and the cluster head.This make nodes select a more appropriate cluster head according to the value of this threshold.This improvementreduces the number of maximum or minimum clusters.3.To solve the problem of unstable number of cluster heads,this paper adds the optimal number of cluster heads in the network.Firstly,find the relationship between the total energy consumption and the number of cluster heads according to the energy consumption model of the network and the clustering process.Then,recken the formula for calculating the optimal number of cluster heads.This improvement narrows the range of cluster heads up and down through the operation of the network.Finally,the improvement of LEACH protocol by the MATLAB and OMNeT++simulation software.The simulation results show the improvement in this paper can balance clustering,the number of cluster heads and network load,and extend the network lifetime.