A Spreading Factor Congestion Status-Aware Adaptive Data Rate Algorithm

Charles Lehong,Bassey Isong,Francis Lugayizi,Adnan Abu-Mahfouz

doi:10.3390/jsan10040070

Abstract

LoRaWAN has established itself as one of the leading MAC layer protocols in the field of LPWAN. Although the technology itself is quite mature, its resource allocation mechanism, the Adaptive Data Rate (ADR) algorithm is still quite new, unspecified and its functionalities still limited. Various studies have shown that the performance of the ADR algorithm gradually suffers in dense networks. Recent studies and proposals have been made as attempts to improve the algorithm. In this paper, the authors proposed a spreading factor congestion status aware ADR version and compared its performance against that of four other related algorithms to study the performance improvements the algorithm brings to LoRaWAN in terms of DER and EC. LoRaSim was used to evaluate the algorithms’ performances in a simple sensing application that involved end devices transmitting data to the gateway every hour. The performances were measured based on how they affected DER as the network size increases. The results obtained show that the proposed algorithm outperforms the currently existing implementations of the ADR in terms of both DER and EC. However, the proposed algorithm is slightly outperformed by the native ADR in terms of EC. This was expected as the algorithm was mainly built to improve DER. The proposed algorithm builds on the existing algorithms and the ADR and significantly improves them in terms of DER and EC (excluding the native ADR), which is a significant step towards an ideal implementation of LoRaWAN’s ADR.

Highlights

IntroductionOver the years Long-Range Wide Area Networking (LoRaWAN) has grown to become one of the leading Media Access Control (MAC) layer protocols in the Low Power Wide
Adaptive Data Rate (ADR), which is the resource allocation mechanism currently being employed in the Long-Range Wide Area Networking (LoRaWAN), has proven to be quite immature and poor performing, especially in dense network scenarios
This paper proposes a modified version of ADR and presents an empirical analysis of its performance in terms of data extraction rate (DER) and energy consumption (EC)

Summary

Introduction

Over the years Long-Range Wide Area Networking (LoRaWAN) has grown to become one of the leading Media Access Control (MAC) layer protocols in the Low Power Wide. Area Networking (LPWAN) space [1]. The LoRaWAN protocol typically runs on top of the. The modulation technique used in the LoRa physical layer is a derivative of the Chirp Spread Spectrum (CSS) modulation and allows technologies such as LoRaWAN to achieve robust multi-kilometre communications while consuming minimal amounts of energy [2]. The popularity of LoRaWAN is owed to its simplicity, openness and cost-effectiveness. Because of the CSS modulation technique which allows for robust long-distance wide-area wireless communications, LoRaWAN is deployed following a simple star topology which keeps it both simple and cost-effective

Results

Discussion

Conclusion