A Research On Coverage With Connectivity-Guaranteeing In Wireless Sensor Networks

Wireless sensor network has been paid more attention in recent years.Sensor nodes have data acquisition,data storing,data processing.They are capable of wireless communication between nodes and nodes,which can send the collecting data by collaboration to the user.In a WSN,the coverage reflects the physical perceived quality of service of the network during monitoring the area or target,and the connectivity indicates the capability of transmitting and receiving data.Coverage and connectivity are the two major concerns of the WSN which affect energy consumption and the network lifetime severely.In a Wireless sensor network,sensor nodes must cover the targets or certain areas in the monitoring area rightly for the perception task.Without the coverage of the target or monitoring area or guaranteeing the connectivity,WSNs will not be capable of completing the goal of perception task and will have no availability eventually.Likewise without suitable node duty cycle and node topology control during the process of monitoring task,the energy of network will soon run out.Then the survival of the network would be threatened.Therefore,the proper plan of monitoring the targets or certain area,topology controlling and duty cycling need to be designed for special monitoring tasks.This dissertation analyzes the research status of WSN cover problem in the world,based on some intelligence algorithms,then use improved BIWO(Binary Invasive Weed Optimization algorithm,BIWO)to solve the cover problem.Firstly,on the basis of the original IWO algorithm to optimize the method of weed encoding and the weed update.The weed is replaced by binary coding composition;The mutated probability of each bit in the parent weed will be calculated by the specific function and specified the mutation bits through specific mapping calculation.Secondly,in order to overcome the drawbacks of IWO,to increase the convergence speed of the algorithm,increase the diversification,to exploit the potential areas to find the global optimum.Adaptive dispersion mechanism isintegrated in the BIWO algorithm.Finally,build network coverage model by Matlab platform.and carry out the simulation experiments.This paper compares the performance on the cover problem of WSN of proposed BIWO algorithm with that of genetic algorithm.Also,the paper compares the the coverage ratio and percentage of dead nodes with different num of nodes and rounds.The related simulation results show that BIWO algorithm has quicker convergence speed,improves coverage ratio remarkably,and prolongs the the lifetime of WSN.The paper also proposes a Shortest path Algorithm for Guaranteeing the Connectivity and the Coverage of WSN,SAGCC).The aim is to form a sensor network connected cover set.Firstly,the sense nodes determine whether they are the redundant nodes through neighbor node sets.Secondly,the redundant nodes turn into sleep preparation mode through node selection rules.The other nodes then turn into the working mode.Then,the load balance can be guaranteed and the blind spot can be avoided.Finally,in order to guarantee network connectivity,auxiliary nodes on the shortest path should be awaked..The simulation experiments are performed by NS-2 on Linux platform.The related simulation results show that the number of working nodes of SAGCC keeps stable with the increase of the number of the deployed nodes.Considering coverage/communication ratio,connectivity,network coverage,SAGCC performs better to most algorithms based on homogeneous network.It is superior to most algorithms of homogeneous networks and is similar to most algorithms of heterogeneous networks with regard to network lifetime.