2026-08-10T23:54:33Z https://drops.dagstuhl.de/oai

oai:drops-oai.dagstuhl.de:23588 2025-10-27T10:21:48Z ddc:004 open_access

LoRaHART: Hardware-Aware Real-Time Scheduling for LoRa Sahoo, Soumya Ranjan Gamage, Amalinda Kumar, Niraj Easwaran, Arvind LoRa LPWAN Real-time Scheduling Hardware Constraints Time-sensitive data acquisition is critical for many Low-Power Wide-Area Network (LPWAN) applications, such as healthcare monitoring and industrial Internet of Things. Among the available LPWAN technologies, LoRa (Long Range) has emerged as a leading choice, offering kilometer-scale communication with minimal power consumption and enabling high-density deployments across large areas. However, the conventional ALOHA-based Medium Access Control (MAC) in LoRa is not designed to support real-time communication over large-scale networks. This paper introduces LoRaHART, a novel approach that overcomes two critical, under-explored limitations in Commercial Off The Shelf (COTS) LoRa gateways that impact real-time performance. LoRa gateways have limited capacity for demodulation of parallel transmissions and their antenna can either transmit or receive at any time instant. LoRaHART incorporates a hardware-aware super-frame structure, comprising both Time Division Multiple Access (TDMA) slots as well as opportunistic retransmissions using Carrier Sense Multiple Access (CSMA), designed to mitigate the above constraints. We use a partial packing and makespan minimization algorithm to schedule periodic real-time transmissions efficiently within the TDMA slots, and also develop a probabilistic node contention model for CSMA retransmissions, providing analytical guarantees for deadline satisfaction under ideal channel conditions. Our evaluation of LoRaHART on a 40-node LoRa testbed demonstrates significant improvements over existing solutions in practice, achieving an average Packet Reception Ratio of 98% and a 45% higher airtime utilization than the best performing baseline. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Soumya Ranjan Sahoo and Amalinda Gamage and Niraj Kumar and Arvind Easwaran 2025 Is Part Of LIPIcs, Volume 335, 37th Euromicro Conference on Real-Time Systems (ECRTS 2025) InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.ECRTS.2025.10 urn:nbn:de:0030-drops-235880 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ECRTS.2025.10 eng https://creativecommons.org/licenses/by/4.0/legalcode