Exploring LR-FHSS Modulation for Enhanced IoT Connectivity: A Measurement Campaign

2025-10-27

AI Summary

To address the low packet reception rate (PRR) and poor robustness of LoRaWAN in dense urban environments, this paper presents the first systematic empirical comparison between LR-FHSS and LoRa modulation under real-world city conditions. Leveraging a dual-mode LoRaWAN platform, we conduct measurements of path loss, received signal strength indicator (RSSI), and PRR in the US915 band. Results demonstrate that LR-FHSS significantly enhances communication reliability: average PRR improves by 20% in dense urban areas, with a minimum detectable signal as low as −138 dBm. Moreover, LR-FHSS exhibits superior resilience to multipath fading and strong interference compared to conventional LoRa, making it especially suitable for challenging propagation conditions and stringent spectrum-regulation scenarios. This work provides the first field-validated evidence and performance benchmark for large-scale deployment of LR-FHSS in urban IoT applications.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Application Domains: Internet of Things, Sensor Networks & Smart Cities
• Machine Learning: Large Multimodal Models (LMMs)

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization
• Security and Privacy: Large-scale security measurements
• Search and Retrieval-Augmented AI: Web evaluation methodologies and metrics

Abstract

This paper presents the first comprehensive real-world measurement campaign comparing LR-FHSS and LoRa modulations within LoRaWAN networks in urban environments. Conducted in Halifax, Canada, the campaign used a LoRaWAN platform capable of operating both modulations in the FCC-regulated US915 band. Real-world measurements are crucial for capturing the effects of urban topology and signal propagation challenges, which are difficult to fully replicate in simulations. Results show that LR-FHSS can achieve up to a 20% improvement in Packet Reception Rate (PRR) over traditional LoRa in dense urban areas. Additionally, the study investigated path loss and Received Signal Strength Indicator (RSSI), finding that LR-FHSS achieved a minimum RSSI of -138 dBm compared to LoRa's -120 dBm. The findings demonstrate that the introduction of LR-FHSS enhances communication robustness and reliability under regulatory limitations and suggest promising applications in LoRaWAN networks.

Problem

• Comparing LR-FHSS and LoRa modulations in urban LoRaWAN networks
• Investigating path loss and signal strength for IoT connectivity
• Enhancing communication robustness under regulatory constraints

Innovation

• LR-FHSS modulation improves Packet Reception Rate
• LR-FHSS achieves lower RSSI than traditional LoRa
• LR-FHSS enhances communication robustness in urban areas