LoRaIN: A Constructive Interference-Assisted Reliable and Energy-Efficient LoRa Indoor Network

2025-06-19

AI Summary

To address the low reliability and high energy consumption of indoor LoRa IoT networks, this paper proposes LoRaIN, a novel link-layer protocol. First, it introduces constructive interference (CI) into indoor LoRa systems—modeling interference and enabling precise timing control to enhance received signal quality. Second, it proposes a lightweight booster node architecture requiring no hardware modification, wherein ordinary end devices collaboratively relay ACK frames in a distributed manner. Third, it designs a joint adaptive mechanism for bandwidth and spreading factor to co-optimize reliability and energy efficiency. Evaluated on a 20-node indoor testbed, LoRaIN achieves a gateway packet reception rate increase from 62% to 95% using only 15% of nodes as boosters, while reducing average end-device energy consumption by 2.5×.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Application Domains: Internet of Things, Sensor Networks & Smart Cities
• Intelligent Robots: Learning & Optimization for ROB

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Security and Privacy: Privacy-enhancing technologies
• Semantics and Knowledge: Methods to enhance, augment, integrate or synergize semantic models such as knowledge graphs and LLMs

Abstract

LoRa is a promising communication technology for enabling the next-generation indoor Internet of Things applications. Very few studies, however, have analyzed its performance indoors. Besides, these indoor studies investigate mostly the RSSI and SNR of the received packets at the gateway, which, as we show, may not unfold the poor performance of LoRa and its MAC protocol, LoRaWAN, indoors in terms of reliability and energy-efficiency. In this paper, we extensively evaluate the performance of LoRaWAN indoors and then use the key insights to boost its reliability and energy-efficiency by proposing LoRaIN, LoRa Indoor Network, a new link-layer protocol that can be effectively used for indoor deployments. The approach to boosting the reliability and energy efficiency in LoRaIN is underpinned by enabling constructive interference with specific timing requirements analyzed both empirically and mathematically for different pairs of channel bandwidth and spreading factor and relaying precious acknowledgments to the end-devices with the assistance of several booster nodes. The booster nodes do not need any special capability and can be a subset of the LoRa end-devices. To our knowledge, LoRaIN is the first protocol for boosting reliability and energy-efficiency in indoor LoRa networks. We evaluate its performance in an indoor testbed consisting of one LoRaWAN gateway and 20 end-devices. Our extensive evaluation shows that when 15% of the end-devices operate as booster nodes, the reliability at the gateway increases from 62% to 95%, and the end-devices are approximately 2.5x energy-efficient.

Problem

• Improving LoRaWAN reliability and energy-efficiency indoors
• Addressing poor performance of LoRa MAC protocol in indoor settings
• Enabling constructive interference for better indoor LoRa communication

Innovation

• Constructive interference with timing requirements
• Relaying acknowledgments via booster nodes
• Boosts reliability and energy-efficiency indoors