Hybrid-Fidelity: Utilizing IEEE 802.11 MIMO for Practical Aggregation of LiFi and WiFi

• Published in: IEEE transactions on mobile computing Vol. 22; no. 8; pp. 4682 - 4697
• Main Authors: Zubow, Anatolij, Gawlowicz, Piotr, Brunn, Carolin, Bober, Kai Lennert, Jungnickel, Volker, Habel, Kai, Dressler, Falko
• Format: Magazine Article
• Language: English
• Published: Los Alamitos IEEE 01-08-2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Accuracy; Channels; Commodities; COTS; Light fidelity; MIMO communication; Optical receivers; Optical transmitters; optical wireless communication; Radio frequency; Radio signals; Signal fading; Signal processing; visible light communication; Waveforms; WiFi; Wireless communication; Wireless fidelity
• ISSN: 1536-1233; 1558-0660
• DOI: 10.1109/TMC.2022.3157452

We present Hy-Fi , a system that aggregates light fidelity (LiFi) and radio frequency (RF)-based communication on the 802.11 (WiFi) physical layer by utilizing the MIMO capabilities in IEEE 802.11-compliant commodity WiFi chips. Hy-Fi is based on two key ideas. First, we use inexpensive commodity hardware to facilitate direct transmission of WiFi waveforms over the optical wireless channel, as this is proposed in the IEEE P802.11bb task group. Second, we use the MIMO signal processing from WiFi to aggregate LiFi and radio signals directly at the physical layer. Hy-Fi was implemented as a prototype and evaluated in a small testbed. Experimental results reveal that our approach offers excellent robustness against signal fading, blockage and external interference in both, the optical and radio channels making it suitable for applications with very strict requirements to the packet delay and loss ratio. Moreover, the two channels, LiFi and RF, can be aggregated to double the link capacity in the best case. Finally, we demonstrate how Hy-Fi could be used as wireless access technology in next-generation indoor enterprise networks providing both high capacity and seamless mobility.