Research And Improvement Of LEACH Routing Protocol For WSN

As a bridge connected of three worlds-human society, natural materials and information field,and with unique technical advantages, wireless sensor network (WSN) always is the research focus ofwireless communication in recent years. The design of routing protocols is one of the importantbranches of researches on wireless sensor networks. With the impact of limited energy of sensor node,energy saving of network protocols is very important, that is, to make the node forward awarenessinformation to destination node with low energy consumption in the purpose of evenly distributingenergy load and extending network lifetime.First, this thesis briefly introduces the routing protocols in wireless sensor network, and discussestheir characteristics, crucial technology and classification. Then we take LEACH, which is a classichierarchical routing protocol, as the research subject, and describe the idea of single-hop clustering,time line of operation and algorithm process, then summarize the advantages and disadvantages of itsexistence. Then we simulate LEACH protocol and Direct with Matlab, and the results show that theadvantage of LEACH in energy efficiency.Second, this thesis improves the LEACH protocol from two aspects: increasing robustness andoptimizing cluster head selection. The first aspect is achieved by establishing candidate cluster headsset; the second one is achieved by creating fitness function with combination of energy, distance,location factors and then applying genetic algorithm. Then it designs the LEACH-GH routing protocol,which is suitable for small and medium-scale network. Experimental simulation comparesLEACH-GH with LEACH and LEACH-C, and the result indicates the advantage of LEACH-GH inenergy efficiency.Finally, this thesis establishes a multi-hop communication model-programming tree usingdynamic programming and designs LEACH-PT protocol on the basis of analyzing the constrains ofsingle-hop clustering LEACH protocol for large-scale networks and the shortcomings of local greedybased multi-hop routing protocol. By comparing LEACH-PT with LEACH and MR-LEACH throughsimulation experiments, we demonstrate that LEACH-PT can achieve energy conservation andprolong the network life cycle, and can be well applied in large-scale wireless sensor network.