A new approach to multicast transmission scheduling in IoT networks

Abstract

The rapid expansion of the Internet of Things (IoT) has led to the deployment of massive networks connecting thousands of lowpower devices that require long-range communication and minimal energy consumption. Among the various technologies enabling such large-scale connectivity, LoRaWAN has emerged as a leading Low Power Wide Area Network (LPWAN) protocol due to its cost efficiency and extensive coverage. However, while LoRaWAN offers scalable uplink communication, the downlink channel remains constrained by limited gateway capacity and duty-cycle restrictions, posing challenges for efficient group communication. To improve downlink performance, this paper proposes a time-slot-based multicast scheduling mechanism that coordinates multicast transmissions across gateways. The proposed approach leverages the spatial distribution of end devices and gateway coverage to identify non-interfering regions, allowing simultaneous multicast transmissions within shared time slots. By implementing this coordination at the network server level, the mechanism achieves reduced collision probability, improved spectral efficiency, and faster data dissemination, particularly beneficial for Firmware Update Over-The-Air (FUOTA) and other multicast-based operations in dense LoRaWAN deployments.