University of Rennes, CNRS, IRISA, 6 rue Kerampont, F-22305 Lannion CEDEX, France.
ETH Zurich, Integrated Systems Laboratory, Gloriastrasse 35, 8092 Zurich, Switzerland.
Sensors (Basel). 2018 May 15;18(5):1578. doi: 10.3390/s18051578.
Wireless sensor nodes are traditionally powered by individual batteries, and a significant effort has been devoted to maximizing the lifetime of these devices. However, as the batteries can only store a finite amount of energy, the network is still doomed to die, and changing the batteries is not always possible. A promising solution is to enable each node to harvest energy directly in its environment, using individual energy harvesters. Moreover, novel ultra-low power wake-up receivers, which allow continuous listening of the channel with negligible power consumption, are emerging. These devices enable asynchronous communication, further reducing the power consumption related to communication, which is typically one the most energy-consuming tasks in wireless sensor networks. Energy harvesting and wake-up receivers can be combined to significantly increase the energy efficiency of sensor networks. In this paper, we propose an energy manager for energy harvesting wireless sensor nodes and an asynchronous medium access control protocol, which exploits ultra-low power wake-up receivers. The two components are designed to work together and especially to fit the stringent constraints of wireless sensor nodes. The proposed approach has been implemented on a real hardware platform and tested in the field. Experimental results demonstrate the benefits of the proposed approach in terms of energy efficiency, power consumption and throughput, which can be up to more than two-times higher compared to traditional schemes.
无线传感器节点传统上由单个电池供电，人们为最大限度地延长这些设备的使用寿命付出了巨大的努力。然而，由于电池只能存储有限的能量，因此网络仍然注定会死亡，而且更换电池并不总是可行的。一种有前途的解决方案是使用单个能量收集器使每个节点能够直接从其环境中收集能量。此外，新兴的超低功耗唤醒接收器允许以可忽略的功耗连续监听信道。这些设备支持异步通信，进一步降低了与通信相关的功耗，这通常是无线传感器网络中最耗电的任务之一。能量收集和唤醒接收器可以结合使用，从而显著提高传感器网络的能量效率。在本文中，我们为能量收集无线传感器节点提出了一种能量管理器和一种利用超低功耗唤醒接收器的异步介质访问控制协议。这两个组件旨在协同工作，特别是要适应无线传感器节点的严格约束。所提出的方法已经在实际硬件平台上实现，并在现场进行了测试。实验结果表明，与传统方案相比，所提出的方法在能量效率、功耗和吞吐量方面具有优势，最高可提高两倍以上。
