Research On Data Transmission Scheme In Sensor Network Based On Node Adaptive Duty Cycle

Wireless sensor networks are widely used in industry,agriculture and other fields because of their high flexibility and easy deployment.However,due to the limited communication capability and energy of these sensing devices,the large amount of data generated and perceived in the event of emergencies can easily cause network congestion,which brings great challenges to the efficient data transmission of wireless sensor networks.In order to alleviate network congestion and improve data transmission quality,this thesis studies the data transmission scheme based on adaptive duty cycle of nodes in wireless sensor networks,mainly including the following aspects:(1)Aiming at the problems of network congestion,loss of a large number of data packets,and high energy consumption caused by data retransmission in wireless sensor networks,this thesis proposes a congestion control scheme based on adaptive duty cycle(Adjust the Duty Cycle of All Nodes,ADCAN).In this scheme,the duty cycles of nodes are adaptively adjusted according to the packet arrival rate,the number of packet loss and the size of buffer occupancy,so as to adapt to the dynamic change of network.Compared with the Fixed Duty Cycle scheme,ADCAN can significantly reduce the number of lost packets by 79.53%-100% and buffer occupancy by 18.99%-22.92%.(2)Aiming at the problems such as network congestion and data packet loss caused by large fluctuation of data volume,this thesis proposes a scheme of Adjust the Duty Cycle to Closely Follow Network(ADCCFN).Based on ADCAN,this scheme considers the influence of the change of data packet arrival rate on the scheme design,analyzes two different stages of the network state,and optimizes the adjustment of node’s duty cycle,so as to adapt to the highly dynamic network.Experiments show that ADCCFN can reduce the number of lost packets by up to 56.46%compared with ADCAN and the node energy consumption is basically unchanged.(3)Aiming at problems of high data transmission delay,large energy consumption and unbalanced energy consumption,this thesis proposes a comprehensive optimization scheme for network performance,and proposes two schemes according to the above problems: A scheme of Notify the Upstream Nodes to Detour(NUND)is proposed for networks with large data traffic and unbalanced data distribution.When congestion is about to occur,this scheme reduces packet loss and energy consumption by increasing node’s duty cycle and notifying its upstream nodes to reduce the amount of data forwarded.Experiments show that NUND can reduce the number of lost packets by up to 33.33% and the energy consumption by 11.03%;the scheme of Increasing the Duty Cycle of Far Sink Nodes(IDCFSN)is proposed for networks with high real-time requirements.In this scheme,the duty cycles of nodes in the far sink area are increased by remaining energy,while the duty cycles of nodes with the largest energy consumption remain unchanged,which can effectively reduce the network delay by 20.95%-77.85% without affecting the network lifetime.