A New Schedule-Based Scheme for Uplink Communications in LoRaWAN

Abstract

Long Range Wide Area Network (LoRaWAN) is currently one of the leading communication technologies for the Internet of Things (IoT) connectivity. It offers long-range and wide-area communication at low-power, low cost and low data rate. However, several studies demonstrated that LoRaWAN exhibits excessive collisions and thus performance degradation especially at large scale. This is mainly due to the ALOHA-based channel access technique adopted for uplink communications in LoRaWAN. In this work, we present a new schedule-based schema which allows a deterministic allocation of time, channel and spreading factor, for a collision-free uplink communication in LoRaWAN. For the sake of interoperability, our schema does not involve any additional synchronization phase for end-devices, or major changes in LoRaWAN specification as suggested in most of the existing studies in the literature. The performance evaluation of our proposed scheme proved an outstanding improvement of the network performance in terms of latency and energy-consumption. For instance, for an inter-packet transmission interval equal to 1800s (one packet each 30 min) and a cell size equal to 1000 end-devices, results show that using the proposed schedule-based schema, the uplink communication latency and energy consumption are reduced respectively by 89% and 78%, compared to the original LoRaWAN legacy class A.