Toward Hybrid COTS-based LiFi/WiFi Networks with QoS Requirements in Mobile Environments

2025-10-31

AI Summary

To address the delayed QoS guarantee in commercial LiFi/WiFi hybrid networks under mobile scenarios, this paper proposes two physical-layer signal–based predictive vertical handover mechanisms. Specifically, it dynamically forecasts LiFi link degradation by monitoring either received optical power (RSS) or CRC packet loss rate, triggering proactive handover to WiFi before violating predefined QoS thresholds (e.g., 20 Mbps throughput). Unlike conventional reactive approaches relying solely on connection failure detection, our method enables QoS-driven, anticipatory decision-making. Evaluated on a real-world testbed comprising commercial LiFi/WiFi equipment, real-time channel quality monitoring, and a conveyor-belt mobility platform, the proposed schemes reduce QoS outage duration to under one second—improving upon baseline methods by multiple orders of magnitude. This significantly enhances handover timeliness and communication continuity, providing a practically deployable, protocol-level solution for LiFi commercialization.

Technology Category

• Planning, Routing, and Scheduling: Plan Execution and Monitoring
• Search and Optimization: Learning to Search
• Humans and AI: Human-Aware Planning and Behavior Prediction

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Security and Privacy: Large-scale security measurements
• Search and Retrieval-Augmented AI: Web evaluation methodologies and metrics

Abstract

We consider a hybrid LiFi/WiFi network consisting of commercially available equipment, for mobile scenarios, where WiFi backs up communications, through vertical handovers, in case of insufficient LiFi QoS. When QoS requirements in terms of goodput are defined, tools are needed to anticipate the vertical handover relative to what is possible with standard basic mechanisms, which are only based on a complete loss of connectivity. We introduce two such mechanisms, based on signal power level readings and CRC-based packet failure ratio, and evaluate their performance in terms of QoS-outage duration, considering as a benchmark an existing baseline solution based on the detection of a connectivity loss. In doing this, we provide insights into the interplay between such mechanisms and the LiFi protocol channel adaptation capabilities. Our experimental results are obtained using a lab-scale testbed equipped with a conveyor belt, which allows us to accurately replicate experiments with devices in motion. With the proposed methods, we achieve QoS outages below one second for a QoS level of 20 Mbps, compared to outage durations of a few seconds obtained with the baseline solution.

Problem

• Hybrid LiFi/WiFi networks require QoS-aware vertical handover mechanisms
• Standard connectivity loss detection causes prolonged QoS outages in mobility
• Proposed methods reduce QoS outage duration using signal and packet metrics

Innovation

• Hybrid LiFi/WiFi network using commercial equipment
• Early vertical handover based on signal metrics
• Experimental validation with moving device testbed