Introducing QoS Classes to Provide Different Levels of Reliability in LoRaWAN Downlink

LoRaWAN supports bi-directional communication, allowing end-devices not only to transmit data to the network server (uplink), but also to receive commands or configuration updates from the network server (downlink). Although most of the research has focused on uplink performance, downlink traffic plays a critical role in enabling control, configuration, and actuation in industrial scenarios. LoRaWAN defines three device classes that offer different Quality of Service (QoS) levels for downlink communication, but they do not specifically address reliability. This work introduces three QoS classes for LoRaWAN downlink that enable configurable trade-offs between reliability and end-device energy consumption. Moreover, this work investigates novel gateway selection strategies that dynamically schedule downlink traffic according to the required QoS levels. Preliminary simulation results show that the proposed strategy significantly improves the packet delivery ratio for downlink transmissions requiring reliability, especially in scenarios with mixed QoS requirements, at the expense of increased energy consumption.