Some Key Issues On Energy-Efficient Methods For Wireless Sensor Networks

Wireless sensor networks are emerging technologies,which adopts distributed information processing techniques with high precision monitoring, fault-tolerant performance,large coverage areas,remote monitoring and many other advantages.It can be founded for the military purpose,intelligent traffic and E-hospital, etc.Thus,it has become a hotspot in research area.But wireless sensor networks have several special characteristics which include shortage of energy,difficulty with energy supply and so on.It's the bottleneck in current application of wireless sensor networks. So how to prolong the lifetime of wireless sensor networks by reducing power consumption to ensure the network coverage has become a new research area.The dissertation focus on energy issues of wireless sensor networks,including energy management from the use of redundant nodes and the nodes of density, energy-saving routing based on the movement of nodes and wireless sensor network management.In addition,this thesis presents the corresponding solutions.The research work was funded by the National Natural Science Foundation project "Ad Hoc network management and performance assessment of public key technology research (No.60572035)" and the project of Beijing Municipal Communication and Information System Key Laboratory under Grant No.JD100040513.The part achievement of the thesis has gotten a national invention patent authorization(NO.ZL200610067188.7).For the energy-efficient methods on wireless sensor networks,the main contributions of the dissertation are as follows:1.An energy-efficient redundant nodes tree mechanism has been proposed.Its basic method proposes an energy-efficient redundant nodes tree mechanism in which the redundant nodes in each cluster can be used to relay information to the base-station. The principle is that the redundant nodes relay tree is constructed according to the position of the redundant nodes and all the information received by the cluster heads is sent to the closest redundant node of the redundant nodes tree.The selected redundant node transmits the information to the base-station by the relaying of the redundant nodes tree.Simulation results show that this method can improve the lifetime of wireless sensor networks efficiently.2.This thesis presents a method which evaluates the distribution uniformity of the entire wireless sensor network.This method adopts a series of parameters which include compression discrepancy,sparseness discrepancy,self discrepancy, maximum cavity radius and minimum cavity radius to evaluate the nodes distribution uniform performance.The method can measure the distribution uniformity of wireless sensor network nodes under the condition that the nodes are deployed randomly.3.This thesis presents a new grid movement based deployment algorithm of wireless mobile sensor networks.The new algorithm reduces the time complexity of WMSN deployment algorithm.The new algorithm,which enhances the coverage degree of the task area and cut down the coverage hole,can adapt to the application on WMSN.The proposed algorithm meets the requirement of coverage of the network deployment under the circumstances of reducing the algorithm complexity.In order to save the energy of wireless sensor networks,the corresponding adjustment strategy is to makes maximum cavity radius and minimum cavity radius infinitely close to,which gives the basic node motion solution.4.This thesis proposes a node motion.This paper explores the motion capability and proposes a kind of node motion solution,including the way to identify the redundant sensors,the way to search for agency node and the way to choose the best node movement route.The method,which considers the factors of energy consumption, remaining energy and node distributing density,makes use of Analytic Hierarchy Process(AHP).So we can find out the best node movement route under many condition controls,in order to prolong the lifetime of wireless sensor networks.5.This thesis presents a generic large-scale(a variety of business,a number of regions, the large node number) of wireless sensor networks integrated network management system of tiered model.The whole model is divided into five levels,as the following order from top to bottom:integrated management,operations management,network management agents,and gateway and network management node management unit. It's main function including accounting management,configuration management, performance management,fault management,security management,energy management,perception management,communication management and strategic management.The model's reliability was analyzed and simulated in this work.6.This thesis presents a data exchange model of generic large-scale wireless sensor network management system,which defines the data interactive method and interface standards among the model,gateway nodes and other network management system.In the corresponding exchange in the original language,in order to reduce the impact of each other,achieve maximum decoupling;avoid using obstructive manner in the interactive process,this interface standard used asynchronous message mechanism.