A Survey of LoRaWAN Adaptive Data Rate Algorithms for Possible Optimization

The Adaptive Data Rate (ADR) is used in LoRa WAnto ensure optimized data rates and transmission powers for static end devices. However, its implementation is still new, and therefore, its functionalities are limited. Multiple proposals have been made to help improve the ADR but an optimum solution is yet to be found. Therefore, this paper surveyed nine most relevant papers with the goal of identifying the ADR challenges and critically analyzing the solutions put forward to solve them. The critique of the solutions was based on the problems they solve, how they solve them, and the improvements they achieved. Findings show that the poorly designed ADR algorithm results in increased collisions and unfairness in collision probabilities amongst network traffic in LoRaWAN. Furthermore, the findings show that the studies surveyed had limitations in terms of the data rates investigated, the transmission parameters considered, and the region in which they were conducted. To help mitigate some of these challenges, few suggestions are presented in this paper.