Gateway Energy-Oriented TDMA for LoRa Networks

Low Power Wide Area Network (LPWAN) has been established as the leading communication technology for the Internet of Things (IoT) era and the latest machine-to-machine (M2M) communication applications. Among various flavors of this communication paradigm, LoRa stands out as the most widely adopted one, due to its low power and long-distance characteristics. The motivation for this study arises from the growing demand for sustainable IoT connectivity in remote or off-grid environments, where gateways often operate under severe energy constraints. Ensuring their long-term functionality is essential, as gateway energy depletion can compromise the entire LoRa network’s operation and reliability. In this work, the contribution of a Gateway Energy-Oriented Time Division Multiple Access (GEOT) communication protocol to the longevity of the network is under scrutiny. In contrast to the majority of the established works that study the effects of the nodes’ energy consumption on the network lifespan, this work investigates the impact of gateway energy consumption and proposes a novel communication scheme tailored to the operational characteristics of gateways in LoRa systems, especially for deployments lacking access to the power grid. Following the same rationale, the proposed scheme is evaluated under various node-placement distributions to represent different application scenarios. Simulation results show that GEOT, when applied to gateways powered solely by renewable energy sources, extends the network lifetime by approximately 4.7 to 6 times compared to conventional solutions, depending on the spatial distribution of the nodes.