Research On Resource Allocation Strategy In Wireless Body Area Networks

With the acceleration of the aging of the population,the health problems of the middle-aged and elderly have received more and more extensive attention.At the same time,more and more food safety issues pose a great threat to people's health.These health problems lead to rising numbers of sudden-onset diseases,heart diseases,chronic diseases,and cancer deaths,meanwhile early diagnosis and treatment can effectively reduce the mortality rate of the disease.With the development of communication tech-nology and sensor technology,wireless body area network as a promising network can be widely used in the long-distance health monitoring to provide people with long-term,real-time and ubiquitous health monitoring.In the development of wireless body area networks,there are many challenges as follows:1)Resource-constrained sensor nodes;2)High Quality of Service(QoS)re-quirements;3)Dynamic link characteristics;4)A wide range of application scenarios.These challenges are related to each other and affect each other.Therefore,with com-prehensively considering the various challenges of wireless body area network under the conditions of dynamic links and multiple application requirements,how to design the effective resource allocation strategy for the guarantee of service quality and the extension of system lifetime is worth exploring in depth.Therefore,this dissertation focuses on two kinds of power supply scenarios in wireless body area network:the lim-ited battery power supply and the energy harvesting module power supply,and conducts systematic and in-depth research on the resource allocation strategy in the wireless body area network.The main contributions of this dissertation are given as follows:(1)A transmission rate adaptive resource allocation strategy is proposed,which has high efficiency and quality of service under the condition of limited battery power sup-ply.Specifically,after considering the characteristics of energy constraints,dynamic link characteristics and high service quality requirements in WBANs,a QoS optimiza-tion problem is proposed to optimize the resource allocation.Due to high dynamic link,the QoS requirement may not be satisfied,which will lead to the problem of resource al-location optimization which can not be solved properly.Therefore,a transmission rate adaptation strategy is proposed to assist the resource allocation strategy.This strategy can adaptively adjust the transmission rate of wireless nodes according to the satisfac-tion of the quality of service,and then it can assist optimization of resources to optimize service allocation.The final comparison experimental results show that,under the con?dition of high dynamic link quality,the transmission rate adaptive assisted resource allocation strategy can guarantee the high service quality demand of the system.At the same time,this strategy can also obtain the best system energy efficiency performance.(2)A buffer-aware resource allocation strategy is proposed under limited battery power supply conditions.Specifically,in order to deal with multiple application re-quirements in the wireless body area network,a mixed cost function is designed to comprehensively evaluate the system energy efficiency and the satisfaction of service quality,and then a mixed-cost minimization problem is proposed to optimize the re-source allocation for meeting the system's requirements of energy efficiency and QoS.In order to further improve the short-term QoS,a low-complexity buffer status eval-uation method is proposed.This method can evaluate the buffer status of each wire-less node in real time,and finally decide whether to re-allocate resources to cope with the blocked packets according to the node's status.Contrasting experiments show that timely reallocation of resources can effectively solve the problem of blocked data pack-ets in the node buffer due to dynamic links,which can improve the performance of the system.(3)A high-efficient resource allocation strategy for energy-harvesting powered WBANs is proposed.First,the statistical characteristics of the energy harvesting pro-cess of each node are explored,and a joint power and source rate control strategy is pro-posed to maximize the system throughput.Therefore,the energy neutral operation state can be achieved by optimizing the source rate and transmission power.Then the nodes are classified according to the real-time residual energy of the nodes and the blocked data packets.For different node types,the corresponding time slot allocation strategy is designed,and the service quality of the system and the utilization of resources are im-proved by effectively allocating time slots.Experimental results show that the strategy can make full use of the time-varying energy collected by the nodes to improve the sys-tem throughput and QoS performance,and the time slot allocation strategy effectively improves the utilization of system bandwidth resources.