## 1 Introduction
A system achieving a bit rate of 7.14 Mbps over an optical link of 6.7 cm was developed in [12], whereas the system proposed in [13] managed video transmission at a rate of 0.115 Mbps over an optical link of 1 m. The research shared in [14] demonstrated a system transmitting video at a rate of up to 0.115 Mbps over a 5 m distance between the transmitter and receiver. Lastly, the proposal in [15] was based on high-powered lasers, which are infeasible for applications involving people due to potential damage to the cornea of the eyes [5] and skin [6]. Conversely, the study conducted in [16] illustrates how Orthogonal Frequency-Division Multiplexing (OFDM) modulation can be employed for boosting spectral efficiency in VLC systems, thereby achieving data rates of up to several Gbps. A development closely related to VLC is Light Fidelity (LiFi) technology, which integrates bidirectional and multi-user communication. This technology forms wireless optical networks with seamless handover capabilities supporting user mobility. LiFi offers higher bandwidth and transmission rates compared to radio frequency (RF) technologies such as WiFi. Although LiFi cannot penetrate opaque objects, this limitation can be advantageous for applications requiring high security levels. Our proposed optoelectronics interfaces can be utilized to provide an innovative solution for transmitting UHD multimedia content in public transportation settings. By utilizing existing reading lights in public transport vehicles, our system sets itself apart from previous studies. Moreover, to our knowledge, no work has reported a VLC system capable of transmitting UHD video using an LED as a transmitter. Additionally, our system offers the flexibility of selecting the modulation scheme--be it On-Off Keying (OOK), OFDM, or any other scheme implemented in the FPGA--by simply toggling a switch. By employing OFDM modulation, our system can achieve data rates comparable to those reported in prior studies. Further, by leveraging high-efficiency LEDs and advanced signal processing techniques, our scheme enhances the transmission rate and improves energy efficiency and connection stability. In this study, we conducted experimental tests in a passenger van, a specific environment that aptly represents the broader public transport context. Passenger van's, commonly used for passenger transport in many metropolitan areas, share key operational characteristics with other public transportation modes such as buses and trains. These features include constant movement, the presence of multiple users, and the need for efficient and secure communication systems. Testing in a passenger van allowed us to evaluate the VLC technology under controlled yet realistic conditions, facilitating an accurate observation and measurement of the system's performance. Since there is a similarity in lighting infrastructure and usage conditions, the results obtained can be extrapolated to other public transportation vehicles. Therefore, this experimental approach provides valuable and applicable information for implementing VLC systems in public transportation. The integration of VLC in public transport offers several advantages over traditional wireless technologies. Unlike WiFi and RF, VLC is immune to electromagnetic interference, a crucial element in densely populated environments like trains and buses. Recent studies suggest that VLC can achieve higher spectral efficiency and transmission rates, reaching up to several Gbps in controlled scenarios [16]. Additionally, the ability to utilize existing lighting infrastructure significantly reduces deployment and maintenance costs. These advantages make VLC an ideal solution for enhancing user experiences in public transportation by providing a secure, fast, and reliable connection for streaming UHD multimedia content. The studies conducted in [7; 8; 12] also attest to the viability of VLC for real-time applications, a critical aspect of its implementation in transportation systems.