The Key Technology Research Based Energy-Efficient In Wireless Sensor Networks

Wireless sensor network(WSN)is a self-organizing networks consist of low-cost,low-power tiny sensor nodes that can wireless communication with each other to perform sensing,data processing and storage cooperatively.Wireless sensor node is a tiny device with limited power,and change battery is almost impossible in some applications.This makes the lifetime of nodes mostly depend on the battery,so reduced power consumption to extend the lifetime of network is the primary problem in the research.Network hierarchical mechanisms,network coverage have closely related with energy consumption,clustering algorithm play a decisive role in Network hierarchical mechanisms.How to deploy the nodes and how to find out the redundant nodes is an important factor on network coverage.This paper carry a deep research mainly on clustering algorithm,deploy of nodes and search algorithm of the redundant nodes from energy efficient.The main research and contributions are as follows:1.This paper proposes an energy efficient maximum-Votes and Load-balance Clustering Algorithm(VLCA),and further validates energy consumption by apply the algorithm in practical scenarios.In large-scale wireless sensor networks,all information collected by each node will eventually be to the sink nodes.This information can be transferred to sink by single-hop or multi-hop.Research show that energy consumption of network will be fewer and the lifetime of network will be longer if nodes are organized in the form of cluster.Much energy efficient routing protocols are designed depends on the cluster structure.In hierarchical network,cluster heads can collect and aggregate data from its cluster members,and make the large amount of data to be little effect information,and then send the information to the sink by multi-hop communication.The cluster head managements cluster members by TDMA protocol. Functions of the cluster members are relatively simple,and do not need maintain complicated routing information,greatly reducing routing control information,has a good scalability.Because cluster heads could be elected at any time,hierarchical network have strong ability to withstand destroy.On the base of analysis WSN clustering algorithm,this paper proposes an energy efficient maximum-Votes and Load-balance Clustering Algorithm(VLCA).A node's importance should be reflected from all its neighbors(include itself)insead of from its local properties alone.Sensors collect votes from their neighbors and calculate the total vote received.The more votes a sensor accumulates,the more important it is in the whole network.Node casts a vote for its neighbor depends on all residual energy of the node and its neighbor.This paper provides the pseudo code of the algorithm and theoretical analysis,and compares it with sutra clustering algorithm.This algorithm is completely distributed,location-unaware and independent of network size and topology.Simulation results show that our algorithm can reduce the number of clusters by 20%-50%.We further apply the algorithm in practical scenarios,and prolong the lifetime of a sensor over that of existing energy-efficient clustering protocols.2.This paper proposes two valid deployment mechanisms of sensors,and extends further two linear network model to a large-scale networks,and validates an uneven clustering routing mechanism from the perspective of energy consumption.As well as orientation and track,deployment of the nodes is the basic problem,which reflects the cost and monitoring ability of WSN.The strategy of deployment can enhance network monitoring quality and reduce energy consumption,and eventually extend node's life. Using an extension of energy consumption model of the wireless sensor node and two linear network models,this paper analyzes the energy consumption and energy efficiency by individual nodes and the network as a whole,when there are multiple transmission sources.By contrast,we propose two valid deployment mechanisms of sensors.First,when nodes are deployed with equidistant spacing,there is an optimum one-hop transmission distance d_opt,and it is independent of the physical network topology,the number of transmission sources,and the total transmission distance.It only depends on the propagation environment and the device parameters.Second,more improving energy efficiency,balancing every node's load,extending a network's lifetime,another deployment mechanism is that nodes are deployed with optimal spacing;every node optimal spacing formula is present.Two deployment mechanisms of sensor nodes are good useful with energy efficiency in wireless sensor networks.Combining network hierarchical mechanisms with the two deployment mechanisms, we extend further two linear network model to a large-scale networks,and validates an uneven clustering routing mechanism from the perspective of energy consumption.As the distance between cluster head and sink is large,research show that communication between cluster head and sink reduces energy consumption by multi-hop forwording model,but it arises a problem of energy consumption unbalance.On the "many-to-one" traffic patetrn as all sensor nodes send data to the sink node,the cluster heads closer to sink are burdened with every relay traffic,they will die much faster than the other cluster heads,reducing sensing coverage and causing network partitioning,which reduces the network lifetime.Based on the analysis of cluster network,the deployment of the network,this paper design an uneven clustering protocol in wireless sensor network.For large-scale networks we carry out uneven clustering using VLCA,cluster heads manage its members by TDMA mechanism.Cluster heads collect and aggregate the data from its members,and then transmit the data to sink via multi-hop communication. Base on the two valid deployment mechanisms of nodes,and given r from cluster head to sink,there is an optimal hopk_opt=r/d_opt.When k_opt-1 relay nodes lie in k_opt equidistant partition between cluster head and sink,energy consumption of end-to-end transmission is minimized.However,in practical network environment,restricted by the node density,it is not reliable that we find relay node just in each k_optequidistant partition.It is a good choice that we select the nearest node to k_optequidistant partition, thus we maximized to reduce energy consumption of end-to-end transmission.This is the basic idea of our multi-hop routing.In order to validate the routing protocol,we carry out even-clustering and uneven-clustering for the network by VLCA,and transmit data to sink by our routing protocol,and compare its energy consumption and lifetime. Simulation results show that the uneven clustering routing mechanism can balance every node's load and energy consumption,further extend a network's lifetime. 3.This paper proposes a redundant node search algorithm based on border coverage, and apply the algorithm to the dynamic coverage control mechanism with tracking mobile target.Each node has a limited sensing range,when a large number of sensors are deployed randomly in the monitoring region,this meight produce the coverage-overlap between sensing range of nodes,thus cause the appearance of redundant nodes. How to search these redundant nodes and control their regular sleep is the problem of coverage control.Because sleep nodes does not consume energy basically,so network energy consumption.can be reduced greatly.Therefore,this paper proposes a redundant nodes search algorithm EDRNS(Efficient Distributed Redundant Node Search), realizing the static coverage control of the entire network.Through transforming about the coverage range from two-dimensional space to one-dimensional space,The EDRNS algorithm can effectively simplify and reduce the complexity of the problem.The algorithm not only can guarantee the overall coverage of the monitoring region,but also can quickly search redundant nodes in the network. All nodes implement the redundant node search algorithm by themselves,if the redundancy of nodes in the monitoring region is lower,the algorithm can be ended early, thus reducing the additional computation,and the energy consumption of the system.Today most coverage control mechanism is static,it means that we control and manage the entire network by static mechanism,so coverage region is fixed.But in some application scenarios,such as mobile target tracking,most nodes which are farside from the target cannot sense the target or the error of the sensing datas,if these sensor nodes are in active,which will be of no value,moreover this will waste the energy of the sensor node.If we use dynamic coverage control,we only implement coverage control around a mobile target,and the coverage region varied with the mobile target,which can effectively avoid energy waste of static topology management. Therefore,this paper implement a dynamic coverage control algorithm ID-DCC (Information Driven Dynamic Coverage Control)which is suitable for tracking mobile target.Namely through constructing effective management-regions nearby the mobile targets,only the nodes in management-regions responsibly completed the requested task,the rest nodes outside the management-regions were put in sleep;At the same time,the ID-DCC algorithm unified the EDRNS algorithm to further carry on the coverage-redundancy control to the management-regions,therefore effectively reduce the overall energy consumption of the network system.