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

TL;DR

This paper proposes and evaluates two novel mechanisms for predicting vertical handovers in hybrid LiFi/WiFi networks to ensure QoS, demonstrating significant improvements in outage duration over baseline methods.

Contribution

It introduces two new prediction mechanisms based on signal power and CRC failure ratios for better QoS in hybrid LiFi/WiFi networks.

Findings

QoS outages are reduced to below one second with the proposed methods.

The mechanisms outperform the baseline solution based on connectivity loss detection.

Experimental validation uses a lab-scale testbed with a conveyor belt for mobility simulation.

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.