Research And Improvement On The Routing Protocol Of Wireless Sensor Network

The four technologies including sensor, embedded computing, network and wirelesscommunication breed wireless sensor network. At present, wireless sensor network can bewidely applied in military, civil use, medicare, environmental monitoring and other fields.Wireless sensor network is generally composed of a great number of sensor nodesdistributed randomly, and its main task is to collect the information in monitoring areas anddeliver it to observers. In wireless sensor network, the energy, computing power andbandwidth carried by sensor nodes are very limited, and that energy is generally providedby batteries, and it is not easy to supplement the power of batteries, therefore, thetraditional wireless routing protocols are not suitable for wireless sensor network. Thus itcan be seen that designing the routing protocol which can save energy effectively, reducethe energy consumption of nodes and extend the life of network is the important topic inthe study on wireless sensor network.Based on studying the existing typical wireless sensor network protocol, the paperfocuses on Leach protocol for the study. Leach protocol is the first layered routing protocolwhich is suitable for wireless sensor network, and it was designed by some researchersfrom Massachusetts Institute of Technology. Its selection mechanism of cluster heads candistribute energy consumption equally to each node to reduce the energy consumption ofentire network, so as to achieve the goal of extending network’s survival time. Incomparison with common planar multi-hop routing protocol and static layered routingprotocol, Leach protocol can extend the life cycle of network by15%.The paper studies and improves the Leach routing protocol of wireless sensor network,and completes the following work tasks:1) Studying the development history, conception, topological structure andcharacteristics of wireless sensor network, the current situation of researches at home andabroad, as well as the composition and protocol stack of sensor nodes, and explaining thedesign criteria and classification of wireless sensor network routing protocol.2) Analyzing the classical planar routing protocols and hierarchical routing protocolsof wireless sensor network from the perspective of topological structure, includingFlooding, SPIN, Directed Diffusion, Leach, TEEN, and so on.3) Focusing on studying the classical routing protocol Leach based on the tasks mentioned above, to mainly analyze its energy model, workflow, advantages anddisadvantages, and so on.4) Putting forward Leach-es protocol and Leach-dd protocol for the shortcomings ofLeach protocol based on studying Leach protocol. Leach-es protocol puts forward someimprovements for the marginalization phenomena of cluster heads, which adds energy anddistance in the process of selecting cluster heads as limiting conditions. Leach-dd protocolalso puts forward some improvements for the unreasonable position of cluster heads in acluster, which selects temporary cluster heads firstly, then verifies the rationality oftemporary cluster heads’ position, and finally selects formal cluster heads. A comparativeanalysis is implemented through NS-2simulation tool, and the result of simulationexperiment shows that the performance of improved protocols is better than that of Leachprotocol.