Improvement Of LEACH Routing Protocol In Wireless Sensor Networks

Since the energy of each sensor node is limited and doesn't obtain replenished timely in the wireless sensor network. So energy is an important resource in the network, it determines the lifetime of the whole network. Therefore, according to the characteristics of wireless sensor networks to design an efficient routing protocol is an important content for studying the network.An increasing number of routing protocols have been proposed for the in-depth study of wireless sensor network, but each routing protocol was based on different application requirements, only one or some of the parameters were improved and did not improve all the parameters. This paper studies the classical clustering routing protocol LAECH based on the comprehensive comparison of the plane routing protocol and hierarchical routing protocol, a new improved protocol based on LEACH is proposed in view of the disadvantages of this protocol. The main contents are as follows: first, the paper describes the significance under the background of this study. Next, it describes the routing protocol of wireless sensor network, then compares and analyses several classical routing protocols. Last, classical clustering communication protocol of LEACH was analyzed. Aiming at the problems that the LEACH protocol doesn't consider residual energy of node, position of the non-cluster and the cluster heads communicate with base station directly which will bring great energy consumption. So an improved protocol“Improved-Leach”was proposed based on LEACH protocol. Improved-Leach has redefined the threshold in the cluster head selection, consider both the residual energy of the sensor node and the number of rounds the present node not selected as cluster head. The new cluster structure model was brought up simultaneously, when the distance between non-cluster head node and the base station is closer than it is to cluster heads, the non-cluster head node as an isolated node, it communicates directly with the base station in the communication phase. Moreover,to save more energy, it used both hop and multi-hop combination between the cluster head and the base station.The simulation experiments among the Improved-Leach protocol, the original LEACH protocol and several other improved protocols(LEACH-NEW?LEACH-C and Leach-advanced) are carried out in MATLABR2014 a, the experimental results show that, The death node is beginning to appear in the network when it runs about 160 rounds in LEACH protocol,170 rounds in LEACH-NEW protocol,180 rounds in LEACH-C protocol and 210 rounds in Leach-advanced protocol separately, but it runs about 330 rounds when in the Improved-Leach protocol; All nodes have died in the network when it runs about 600 rounds in the LEACH protocol, 730 rounds in the LEACH-NEW protocol, 800 rounds in the LEACH-C protocol and 840 rounds in the Leach-advanced protocol separately, but it runs about 1000 rounds when in the Improved-Leach protocol. Compared with the four protocols, Improved-Leach protocol improves the energy utilization rate of network obviously and extends the network lifetime.