Analysis And Improvement Of Wireless Senor Network Clustering Routing Protocol Based On LEACH Protocol

Wireless Sensor Network is a convergence technology of computer network, communications and sensor. WSN usually is widely applied in the military operations, environmental monitoring, medical rescue, traffic control, home automation and other commercial applications. Study at home and abroad of WSN is not yet mature. Carrying out this cutting-edge technology research timely will bring great value and strategic significance to the development of the country.This article describes the background of improved WSN routing protocols, including a general description of WSN concept and architecture, WSN routing protocol features and key technologies, as well as the plane routing protocols like Flooding and cluster routing protocols as LEACH and LEACH-C. The article analyzes the LEACH cluster head selection algorithm and clustering algorithm, and establishes the energy consumption model of LEACH protocol, and show the optimal cluster number of WSN using the LEACH protocol. Finally, we made some NS2 simulation of several typical routing protocols and analyzed simulation results, summarized their advantages and disadvantages.This article focuses on improving LEACH which is a WSN sub-cluster routing protocols,it establishes a new Leach-ER protocol which based on node residual energy and receiving signal strength through new cluster head election strategy and clustering algorithm. It shows as followings:Firstly, LEACH protocol adopts random cluster head election mode. Sometimes, nodes with lower residual energy or poor communication quality will be elected as cluster heads which makes them premature death and then affect the whole network life cycle. In the cluster head election strategy of Leach-ER protocol, only nodes whose residual energy E and the receiving signal strength indicator (RSSI) are over threshold value can be considered, besides it selects node who has the largest communication link quality (LQI) as their head cluster in the process of clustering. The new cluster head election strategy of LEACH protocol will increase the life cycle of cluster heads.Secondly, Random cluster heads election strategy in LEACH protocol may cause uneven geographical distribution of cluster head nodes. Some head nodes are probably sparsely distributed or far away from the Sink node, which consumes too much energy. Leach-ER protocol takes the receiving signal strength indicator (RSSI) in head cluster election and chooses parent node as cluster head in clustering. This strategy benefits the stability of the network.Thirdly, LEACH protocol assumes that each node can communicate with the Sink node, which is unable being used in large-scale WSN applications. Leach-ER uses multi-hop routing protocol approach, so it can be applied to large-scale WSN.In order to improve the effectiveness, this article uses NS2 network simulator on the Leach-ER protocol and LEACH Protocol in a 200 * 200m2 area of the simulation. Set 2J as the initial energy of all nodes, Sink node is located in the center of the target area, the network's physical layer and MAC layer is IEEE 802.15.4. Simulation includes the network lifetime, network nodes survive, the network energy consumption, simulation results show that the Leach-ER protocol is better than LEACH in these agreements.