QoS Based Spreading Factor Assignment for LoRaWAN Networks in IoT Applications

This paper addresses the issue of meeting communication performance requirements for Internet of Things (IoT) applications using LoRaWAN, an emerging low–power wide– area networking (LPWAN) technology. The proposed approach involves the development of rules for the assignment of LoRa spreading factors to IoT devices to limit the number of packet collisions selectively for devices having high Quality of Service (QoS) requirements. Two different spreading factor assignment schemes are proposed that differ in the assignment rules applied. Performance results, obtained using mathematical models and simulations, indicate that the proposed schemes adequately distinguish between high priority and low priority devices and can meet QoS requirements within limitations of network size.