Heterogeneous Carrier-Sense Multiple Access for Improved Energy Fairness in LoRaWAN

• Published in: International Symposium on Computing and Networking (Online) pp. 172 - 178
• Main Authors: Shao, Chenglong, Muta, Osamu
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.11.2022
• Subjects: carrier-sense multiple access; channel activity detection; Energy consumption; energy fairness; Floors; LoRaWAN; medium access control; Multiaccess communication; Performance evaluation; Proposals; Protocols
• ISSN: 2379-1896
• DOI: 10.1109/CANDAR57322.2022.00031

This paper proposes a heterogeneous carrier-sense multiple access (CSMA) protocol named LoHEC as the first research attempt to improve energy fairness when applying CSMA to Long-Range Wide-Area Network (LoRaWAN). LoHEC is enabled by Channel Activity Detection (CAD), a recently introduced carrier-sensing technique to detect LoRaWAN signals even below the noise floor. The design of LoHEC is inspired by the fact that existing CAD-based CSMA proposals are in a homogeneous manner by having LoRaWAN end devices perform identical CAD regardless of the differences of their used network parameter - spreading factor (SF). This can lead to energy consumption unbalance among end devices since the consumed energy during CAD is significantly affected by SF. By considering the heterogeneity of LoRaWAN in terms of SF, LoHEC requires end devices to perform different numbers of CAD operations with different CAD intervals during channel access. Particularly, the number of needed CADs and CAD interval are determined based on the CAD energy consumption under different SFs. We conduct extensive experiments regarding LoHEC with a practical LoRaWAN testbed including 30 commercial off-the-shelf end devices. Experimental results show that in comparison with the existing solutions, LoHEC can achieve 0.6-0.8× improvement of the energy fairness on average.