Research Article
Hy-LiRF: Hybrid LiFi and WiFi Network Supporting Seamless Real-Time Transmissions
@INPROCEEDINGS{10.1007/978-3-031-96146-5_12, author={Menghan Li and Runxin Zhang and Yuheng Zhang and Yongsheng Gong and Jianhua He and Lu Lu}, title={Hy-LiRF: Hybrid LiFi and WiFi Network Supporting Seamless Real-Time Transmissions}, proceedings={Smart Grid and Innovative Frontiers in Telecommunications. 8th EAI International Conference, EAI SmartGIFT 2024a, Santa Clara, United States, March 23-24, 2024, Proceedings}, proceedings_a={SMARTGIFT}, year={2026}, month={9}, keywords={Visible Light Communications WiFi LiFi Hybrid Communication System}, doi={10.1007/978-3-031-96146-5_12} }- Menghan Li
Runxin Zhang
Yuheng Zhang
Yongsheng Gong
Jianhua He
Lu Lu
Year: 2026
Hy-LiRF: Hybrid LiFi and WiFi Network Supporting Seamless Real-Time Transmissions
SMARTGIFT
Springer
DOI: 10.1007/978-3-031-96146-5_12
Abstract
With rapid advances of visible light communications techniques, also known as light fidelity (LiFi), its integration with ubiquitous WiFi network interface cards (NICs) has been finalized in the latest IEEE 802.11bb standard in 2023. Although LiFi has abundant bandwidth resources that can support higher physical-layer (PHY-layer) data rates over WiFi, pure LiFi communication links are easily interrupted by blockage, which becomes a big barrier for its widely applications. To tackle this problem in LiFi, this paper proposes a hybrid LiFi and WiFi communication design (Hy-LiRF) in which PHY-layer packets are parallelly transmitted using two RF ports of the WiFi NIC, one for LiFi and the other for conventional WiFi. Since the LiFi link has a frequency up-conversion and down-conversion module to match the low-pass characteristics of LED and photo-diode, additional carrier frequency offset (CFO) which may greatly degrade the system BER performance is introduced because WiFi NICs do not know what happened to its PHY-layer. In this paper, we propose a well-designed precoding matrix that is updated in real time based on channel status information to mitigate effects of additional CFO. Simulation results show that this approach effectively lowers the system’s bit error rate to the level where CFO is negligible. Besides, we build a prototype on top of the WiFi NICs’ MIMO RF ports, which achieves a real-time data rate of 140 Mbps within a 40 MHz bandwidth. To the best of our knowledge, Hy-LiRF is the first real-time bidirectional communication system. Experimental results show that Hy-LiRF can maintain communication regardless of obstacles blocking the optical path or radio frequency interference, and restore to the highest communication rate 3 s after the blockage or interference sources are removed, supporting seamless real-time transmissions.