Research On Routing Protocols Of Wireless Sensor Networks

In recent years, the advance of technology and rapid development of sensor technology, Micro-Electro-Mechanism System(MEMS), modern networking and wireless communications have facilitated the rapid growth of Wireless Sensor Networks(WSNs). Therefore, variety of applications in WSNs are paid attention and developed. The sensor node is fairly limited by energy resource, memory, the computation of processor, the communication capability and so on. The limitations of hardware that make the control of energy consumption to become the primary considered factor in various kinds of relevant research of WSNs. Hierarchical clustering is a key technology for reducing energy consumption. But these researches can not make the network topology stable.The paper takes the wireless sensor network routing protocol LEACH as the object of study, analysis its deficiencies. After exploring existing improved models about LEACH algorithm, the paper points out the cluster formation algorithm does not take the energy of cluster head(CH) nodes into account so it makes the structure of clusters unreasonable. On the basis of protocol LEACH-C, protocol CEFL and protocol DCHS, the different phases of network to elect CH and to clustering in WSN are considered. It includes the process of initial phase of network, the process of nodes join or leave a group, and the process of CH fail. In addition, the stability is very important especially in WSN, so the evacuated mechanism of CH's workload is proposed to assign the part of works to the pseudo-cluster head(PCH) to execute when the CH is overload, and retrieve work authority of PCH when the CH returns to normal performance for improving the stability and performance of WSN. To summarize the main points that have been made in this thesis, the proposed mechanism that the PCH assists to process the workload of the CH by the concept of"slow-start"can balance the overload of a CH. Due to the proposed mechanism that can balance the CH load, keeps a stable network topology and prolongs the lifetime of WSN.In this paper, the proposed mechanism is called LEACH with pseudo-cluster head(LEACH-P in short). In brief, this study includes:(1) design a stable clustering and election mechanism to form a hierarchal wireless sensor network topology;(2) balance the workload of CH and reduce the energy consumption of CH;(3) enhance the stability and performance of the whole network;(4) prolongs the lifetime of the whole network. And the NS2 simulation tool is used for simulation analysis. Simulation results show that LEACH-P protocol effectively improves the efficiency of energy utilization, prolongs the network lifetime, achieves network load balancing.