能量捕获无线传感器网络中低时延的可靠数据传递

Reliable data delivery with low delay in energy harvesting wireless sensor network

在能量捕获无线传感器网络(EH-WSN)中,采用网络编码(NC)技术可有效提高数据传递的可靠性。已有的研究成果大多采用固定的数据速率(DR)和固定的最大重传次数(MNR),传输时延较高。为了降低传输时延,结合EH-WSN中节点的能量捕获特性和相邻节点之间的无线链路质量,提出一种优化数据速率和最大重传次数的低时延数据传递方案。通过对节点的能量捕获过程和能量消耗进行建模,给出了节点的剩余能量公式;对相邻节点之间的无线链路质量进行建模,推导出节点发送数据包的成功收包率和每个数据包的期望传输次数,进而推导出传输路径上每一跳的传输时延公式;基于优化方程,在节点满足链路收包率条件和剩余能量条件的前提下,对其数据速率和最大重传次数进行优化配置,使得每一跳的传输时延最小。实验结果表明,与采用固定数据速率和固定最大重传次数的数据传递方案相比,所提出的方案具有最小的端到端传输时延。

Using Network Coding （NC） can effectively improve the reliability of data delivery in Energy Harvesting Wireless Sensor Network （ EH-WSN）. Most of the existing research used fixed Data Rate （DR） and fixed Maximum Number of Retransmissions （MNR） in reliable data delivery, and its end-to-end delay is long. In order to reduce the data delivery delay, a data delivery scheme, which combined the energy harvesting characteristics of EH-WSN node and the link quality between the adjacent nodes, was proposed to obtain low end-to-end delay by optimizing the DR and the MNR. The energy harvesting process and the energy consumption were modeled and the residual energy equation of node was given. The probability of successfully transmitting a packet under the retransmission mechanism was derived by modeling the link quality between the adjacent nodes, and the transmission delay over a hop on the data delivery path was also derived. The proposed scheme can minimize the transmission delay of each hop by optimizing the DR and the MNR based on the optimization equation under the condition that the node can satisfy the constraints of link quality and residual energy. The experimental results show that compared with the fixed DR and fixed MNR data delivery scheme, the proposed scheme can obtain the lowest end-to-end data delivery delay.