A Type Of Mobile Data Collection Method Based On Maximum Recharging Benefit In Wireless Rechargeable Sensor Networks

Obtaining valid data with high-quality is one of the most important functions in WSNs(Wireless Sensor Networks),but the energy problem has become a serious obstacle to its further development.In traditional static sensor networks,although the energy efficient strategies are often used to reduce the energy consumption of nodes,the "energy holes" caused by unbalanced energy consumption frequently occurs;With the help of the mobile Sink,this problem can be alleviated to some extent,but it still can't avoid the end of network lifetime.In recent years,the rapid development of wireless recharging technology has brought new opportunities for the long-term operation of WSNs.In general,a network that uses this technology is called as Wireless Rechargeable Sensor Networks(WRSNs).At present,many in-depth researches have been done on energy replenishment methods,recharging scheduling or mobile data collection methods with wireless recharging.However,there are still some shortcomings in WRSNs,such as insufficient consideration of time dealy on data collection,ignoring the limited battery capacity as well as the energy consumption of Wireless Charging Vehicles(WCVs)on moving and not considering the collaboration between the Mobile Data Collectors(MDCs)and WCVs.To reduce time delay on data collection and to prolong the network lifetime,a type of high-efficient Data Collection method based on Maximum Recharging Benefit(DCMRB)is proposed in this thesis.Firstly,the complete coverage model in WSNs is adopted to determine the number and specific distribution of Virtual Traverse Points(VTPs).Secondly,the minimum number of MDCs is calculated out under the constraints of time delay and buffer overflow.Based on these,the Virtual Scan Line(VSL)method is proposed to evenly divide the network into several regions.Then,one MDC and one WCV are employed in each region for distributed data collecting and energy replenishing.Meanwhile,in order to ensure the integrity of data collection and the fairness of node being recharged,a speed adjustment scheme for MDC and an adaptive calculation method of the recharging request threshold are further proposed.Finally,the limited battery capacity of WCV and its energy consumption on moving are also taken into account,and an adaptive recharging scheme based on maximum benefit is constructed to avoid premature death of nodes.Simulation experiments show that compared with typical recharging algorithms,such as Energy Starvation Avoidance Online Charging Scheme(ESAOC),Greedy Mobile Scheme based on Maximum Charging Benefit(GMS-MCB)and First-Come First-Served(FCFS),DCMRB can notonly enhance the efficiency of data collection,but also improve node survival rate and prolong the network lifetime.