Research Of Energy Holeavoidance In Cluster-based For Wireless Sensor Networks

At present，Wireless Sensor Networks（WSN）crossed by many subjects is apopular research area in the world. It is a novel technology on information acquiring,information processing and communication, which aims to collaboratively detecting，collecting and processing network information in a certain region and sending theinformation back to observers through wireless communication. With the developmentof computer technology, wireless communications, micro-system technology andintegrated circuits, WSN has been applied in more and more fields．There is seriousresources limited in wireless sensor network，therefore，to design routing protocol ofhigh energy efficiency in order to prolong the network lifetime is one of the mostsevere challenges WSN has to face．Firstly, this thesis describes the basic characteristic of WSN and introduces severaltypical routing protocols in detail，and analyzes the good aspects and bad aspects ofthese routing protocols. Then, Researching the energy hole problem of clusteringrouting protocol is the main work of this paper, Energy hole is mainly brought bydirected network traffic–most network traffic is from sensor node to sink node or viceversa. The nodes near to sink node consume energy very fast because of relaying largenumber of packet. To solve Energy hole, This paper propose two new clustering routingprotocol, one is Uneven Clustering protocol based on the Optimal cluster Radius(UCOR), and the other is Clustering protocol based on Energy Balance Routing withnonuniform relay node selection (EBR)The Basic strategy of UCOR is to cluster heterogeneously, generating unequalscaled clusters, which make the cluster close to sink node smaller than the cluster farfrom it. UCOR reserves energy of nodes near the sink for forwarding data inter-clusterby reducing energy consumption for intra-cluster data processing. Compared to othernon-uniform clustering routing protocol, the UCOR optimizes the distribution and sizeof cluster by using the optimal cluster radius. The cluster size grows gradually as thedistance between the cluster head and sink node increase and closes to the optimalcluster size as much as possible. The experiment results show that UCOR balances theenergy consumption of nodes effectively and extends the network life-cyclesignificantly.EBR divides the network to some circular layers and classifies the nodes into sensor node and relay node. Sensor nodes are uniform distributed in network, but relaynodes are nonuniform deployed in network. The number of relay node in each layer iscalculated according to energy balance principle. After deployment, node densityincreases from outer layer to inner layer. This distribution allows the nodes near sinknode can afford much more network traffic. The simulation experiment results showthat EBR avoids energy hole effectively, balances energy consumption among nodesand extend the network lifetime significantly, in the meanwhile maintains the advantageof uniform distribution of sensor nodes.