Random Walk Based On Coverage Holes Recovery In Wireless Sensor Network

Wireless sensor network is constructed by large number of sensor nodes with selforganization, all sensor nodes have the ability of sensing, information collection, data processing and simple data transmission,they can communicate with each other. Small size, low power consumption, low cost,all of these are the biggest characteristics of sensor nodes, because of these characteristics, wireless sensor network are widely used in real life,such as military, medical, Wisdom City and so on.The connection of the physical world becames possible through wireless sensor network, that is objects and objects can be connected and people and objects are connected,which changed the traditional interactive mode between human beings and natural.At present, the social communities are widelyattention to wireless sensor network, also bring the research boom.The sensor module, processor module and wireless communication module of sensor node will consume energy,and the energy power of sensor nodes is limited, There- fore, so sensor nodes will run out of energy at some time,which will lead to the area original covered by the nodes will not be covered, events in this regional could not be detected,this area is called coverage hole, the coverage holes affect network performanc. In the network, covereage holes will appear in a variety of circumstances, such as the uneven deployment, artificial or natural factors that caused nodes failure.How to repair such coverage holes has a important significance.A coverage hole repair work based on mobile node is proposed in this paper, the main research content includes the following parts:1. Briefly introduce the research background, which contains the development history,characteristics,development trends of wireless sensor networks and its application. Summary the related work of the coverage holes in wireless sensor networks,give a brief introduction of coverage hole recovery domestic and overseas and the basic concept and relevant theoretical knowledge of the coverage holes in wireless sensor network.2. Currently, the specific location of cover the holes is known to mobile node and then mobile node moves coverage hole directly in much literatures. This paper makes the most of the local information the node grasped, static nodes detect local coverage holes by local information that collected.According to the rules formed by local information, mobile node moves in the network to find out the existing coverage holes,the rule takes the energy consumption and delay into considering. The simulation experiment proved that, the method is valid, and path to coverage holes that mobile node formed performs better in aspects of the energy consumption and delay.3. After reaching the coverage hole,a specific position is needed to fill the coverage holes.To make full use of node sensing scope,introduce the method of vector geometry. Figure out the best position through the relevant properties of the vector.This method takes account the overlap area between nodes, and minimize the overlap area as far as possible, to recovery holes maximize.Simulation results show that, this method has better performance, in accordance with the theory.