Research On Node Sleep Scheduling Optimization Method Based On Time Switching Of SWIPT

Wireless Sensor Networks(WSNs)is a kind of energy-constrained network,and sensor nodes usually use the fixed batteries to supply power,which resulting in the limited service life of the network.Radio-Frequency(RF)signals used in Simultaneous Wireless Information and Power Transfer(SWIPT)technology can transmit information and harvest energy simultaneously,which is expected to prolong the working life of wireless sensor networks.Node sleep scheduling technology reduces the energy consumption of the network by sleeping part of the nodes without affecting the smooth data path of the network.Therefore,SWIPT and sleep scheduling technology can be used to solve energy constraints problem in wireless sensor networks.Based on wireless energy-carrying sensor networks,this dissertation combines sleep scheduling technology and clustering technology to improve the working life of wireless sensor networks.The main work and achievements of this dissertation are as follows:(1)To solve the problem that the existing sleep scheduling methods do not fully consider the residual energy of nodes and the serious energy constraints of nodes,a centralized sleep scheduling method based on SWIPT is proposed.In this method,the network is divided into energy collection layer and information transmission layer.The wireless charging point of energy collection layer harvests energy and provides energy for sensor nodes of information transmission layer.The information transmission layer adopts centralized topology structure.Time Splitting(TS)method is adopted to realize the cooperative transmission of information and energy.After energy harvesting in the first slot,sensor nodes performs sleep scheduling operation on the nodes in the network according to their residual energy,energy harvested in the first slot,information transmission rate and network connectivity requirements.The nodes are divided into sleep nodes and active nodes.In the second slot,active nodes send information to the sink node,and sleep nodes continue to harvest energy.Finally,according to the user's requirements for energy utilization and network coverage,the appropriate range of slot segmentation factor can be obtained.(2)In order to further improve energy utilization and prolong network lifetime,this dissertation proposes a distributed sleep scheduling method based on SWIPT,which combines clustering technology.The sensor nodes are divided into cluster-head nodes and cluster-member nodes.Cluster-head nodes act as the relay of cluster-member nodes,which can reduce the communication distance of single hop and greatly reduce the energy consumption of information transmission.The process of carrying capacity communication is divided into three slots: in the first slot,the sensor node harvest the energy,and then according to the residual energy of the node,the energy harvested in the first slot and the network connectivity requirements,the nodes are divided into sleep nodes and active nodes by sleep scheduling optimization algorithm,and the active nodes are clustered according to the rate of information transmission and the relative position of nodes;Cluster node sends information to cluster head node,cluster head node receives information,sleep node continues to collect energy;third time slot,cluster head node sends collected information to sink node,cluster member node and sleep node continue to collect energy.Finally,according to the user's requirements for energy utilization and network coverage,the appropriate slot segmentation factor is selected.Compared with the centralized sleep scheduling method,the energy utilization and coverage of the network are improved.