Research On Energy-balanced Hierarchical Routing Methods For WSNs

Wireless Sensor Networks(WSNs)is a wireless ad hoc network which consists of a large number of sensor nodes deployed in a specific monitoring area with perceptual,acquisition and processing capabilities.Due to the advantages such as self-organization and data transmission capabilities,wireless sensor networks are widely used in military detection,environmental science and smart home and other fields,which are also listed as the most influential 21 st technology and one of the world's top ten technologies to change the world in the 21 st century.The wireless sensor network has the characteristics of limited energy and limited communication bandwidth,so it is the primary goal of designing wireless sensor network to extend the network lifetime on the basis of ensuring the safe transmission of information.The energy of the wireless sensor network is mainly consumed in the data transmission,and the hierarchical routing is the core technology of the wireless sensor network.Therefore,it is very important to design a reasonable and efficient hierarchical routing method to extend the network lifespan.In general,the uneven energy consumption of nodes is a major cause of short network life,so the designing of energy-balanced hierarchical routing method can solve the problem of network lifetime.In this paper,two hierarchical routing methods are proposed,which are applied to the square network model and the rectangular network model respectively.The main contents are summarized as follows:1)This paper proposes a variable weight based clustering approach(VWCA).According to the characteristics of the node residual energy is greatly different in different operation stages,the construction of the cluster and data communication process are classified into two stages: the early stage of the network operation and the later stage of the network operation.In the early stage of network operation,the node energy gap is not obvious,then increase the weight of the distance of nodes to enhance the influence of the distance on the formation of clusters and energy costs,mainly to make energy consumption as small as possible.At the later stage of the network operation,the residual energy of some nodes is very small,then increase the weight of the remaining energy of the node to improve impact of the residual energy on the creation of the cluster and routing.The simulation results show that the method is superior to other methods on the key indexes such as the network lifetime,the energy surplus after the different running rounds and the number of surviving nodes.2)A hierarchical routing method based on precise distance is proposed for the "energy hole" problem in striped multi-hop wireless sensor networks.The core idea of the method is to change the amount of data and transmission distance of each layer based on network uneven stratification to realize the energy balance of network.In this method,the network is stratified.Firstly,the average energy consumption of the nodes in the first layer is optimized,and the width when the average energy consumption of first layer node is smallest and the minimum average energy consumption of the first layer node are deduced.Secondly,according to the principle of equal energy consumption of each layer,the precise width and precise transmission distance of other layers are deduced when the network energy is balanced.The simulation results show that the network lifetime,energy consumption equalization and energy residual rate of the method proposed are superior to other methods.