Link-Aware Dynamic Dwell-Timer Handover for Hybrid LiFi/WiFi Networks

The continuous growth in indoor mobile data traffic has led to a high demand for high-capacity, reliable wireless communication infrastructure. Hybrid LiFi/WiFi networks (HLWNets) have emerged as a promising paradigm that combines the high-throughput capabilities of LiFi with the mobility and robustness of WiFi. However, the efficient handling of vertical handovers (VHOs) remains a critical challenge. This is particularly due to LiFi's sensitivity to line-of-sight (LoS) conditions and link disruptions caused by user mobility and environmental obstacles. To address this issue, this paper proposes a Link-Aware Dynamic Dwell Timer Vertical Handover (LA-VHO) scheme that dynamically adjusts the dwell time based on real-time LiFi link availability and unavailability statistics. By incorporating both the blockage and recovery dynamics of the optical channel, the proposed scheme effectively switches between LiFi and WiFi to minimize unnecessary handovers while maintaining high-rate connectivity. Numerical simulations demonstrate that LA-VHO outperforms traditional Immediate VHO (I-VHO) and static Dwell-VHO (D-VHO) strategies, reducing VHO event occurrences by up to 80%, increasing throughput by up to 5 Mbps across various mobility and blockage conditions, and improving signaling efficiency by 30%. These results validate the LA-VHO scheme as a viable and practical solution for future large-scale hybrid LiFi/WiFi networks.