Research On Energy Balance In Clustered Wireless Sensor Networks

Wireless sensor network(WSN) is a self-organizing networks consist oflow-cost low-power tiny sensor nodes that can wireless communicationwith each other to perform sensing ,data relaying and processing andstorage cooperatively. Tiny sensor node has limited power and changebattery is almost impossible in some applications. So reduced energyconsumption to extend the lifetime of network is problem in the research.In the clustered wireless sensor networks, since the nodes closed tosink burdened with heavy relay traffic and becomes disabled afterexhausting its energy because it must transmit a great quantity datacoming from other clusters, it may cause"hot spots"problem. Networkswith"hot spots"problem can not collect data completely, and even thedata collected can not be further transmitted to the Sink, and the lifetimeof network is ended, plenty of under-utilized energy resources are left. Inorder to take advantage of the network energy consumption evenly andextend the lifetime of network, this paper carry a deep research mainly onclustering algorithm, deploy of nodes and detection and repair ofcoverage holes from energy balance. The main research and contributionsare as follows:1. An energy balanced scheme based on variable cell transmissionrange for wireless sensor networks EBS-BVCTR is presented. InEBS-BVCTR, the entire network has been divided into some regionsreasonably, each region have roughly the same number of sensor nodes,so the transmission range controls the number of clusters, largetransmission ranges produce a small number of clusters, thus, energy balanced cluster architecture is chosen based on variable transmissionrange. The simulation results show that the EBS-BVCTR can allocateenergy to each node of network regularly with higher energy efficiency,extend lifetime of network, and alleviate"hot spot"problem of datacollecting network.2. A best fit node policy (BFNP) is proposed. The main idea is thatwhen the base station found the failed nodes in the networks the firstboundary node identified coverage holes: the initial boundary nodebroadcast information to its neighbor nodes to find coverage holes,then its neighbor nodes also broadcast its information of coverageholes, and so on down; and then the boundary information of all theboundary nodes is feedback to the initial boundary nodes by thecoverage of any adjacent two empty intersection of the boundary nodeconnected to form a polygon. The initial boundary nodes begin to drawthe smallest polygon coverage round, and determine its center of acircle; and select the closest inactive node of which is surrounded theborder by smallest coverage circle of polygon, and then replace thefailed nodes, as well as activate the closest inactive node and repairingthe coverage holes. The simulation results show that Best Fit NodePolicy can maintain better quality of coverage, and make full use ofenergy resources, and extend lifetime of networks, moreover, BFNP issuperior to Coverage Hole Patching Algorithm.