From the outset, batteries have been the main power source for the Internet of Things (IoT). However, replacing and disposing of billions of dead batteries per year is costly in terms of maintenance and ecologically irresponsible. Since batteries are one of the greatest threats to a sustainable IoT, battery-less devices are the solution to this problem. These devices run on long-lived capacitors charged using various forms of energy harvesting, which results in intermittent on-off device behaviour. In this work, we model this intermittent battery-less behaviour for LoRaWAN devices. This model allows us to characterize the performance with the aim to determine under which conditions a LoRaWAN device can work without batteries, and how its parameters should be configured. Results show that the reliability directly depends on device configurations (i.e., capacitor size, turn-on voltage threshold), application behaviour (i.e., transmission interval, packet size) and environmental conditions (i.e., energy harvesting rate).

翻译：从物联网诞生之初，电池就一直是其主要电源。然而，每年更换和处置数十亿节废电池在维护成本上耗费巨大，且在生态上不负责任。由于电池是可持续物联网面临的最大威胁之一，无电池设备成为解决这一问题的方案。此类设备依靠通过多种能量收集形式充电的长寿命电容器运行，这导致设备出现间歇性开断行为。本研究针对LoRaWAN设备建立了这种间歇性无电池行为的数学模型。该模型使我们能够表征其性能，以确定LoRaWAN设备在何种条件下可无需电池运行，以及如何配置其参数。结果表明，可靠性直接取决于设备配置（即电容器容量、导通电压阈值）、应用行为（即传输间隔、数据包大小）以及环境条件（即能量收集速率）。