## 1 Introduction
Similarly, private and office spaces benefit from consumer-oriented Li-Fi products, offering internet connectivity through visible or infrared lights [9]. Smart cities stand to gain from VLC's capacity to relieve RF spectrum usage outdoors, providing alternative communication for local, line-of-sight, and short-distance applications [10]. The smart industry sector, including factory automation and logistics, witnesses the potential of VLC in optimizing wireless connectivity within industrial warehouses [11]. Deploying free space optical (FSO) communication as a backhauling system in cities characterized by towering skyscrapers offers a high-capacity and wireless solution for data transmission across urban landscapes [12,13]. The military sector explores the secure, non wall-penetrating nature of VLC, potentially replacing wired communication means for local applications [14]. Healthcare applications leverage VLC for remote health monitoring, aligning with smart health strategies in smart cities [15]. Finally, underwater communication, a traditionally challenging domain, sees VLC's potential to achieve communications in harsh turbulent conditions [16]. This paper critically analyzes and provides the essential tools for integrating VLC communication in short-distance scenarios within urban and industrial settings, contributing to the dynamic landscape of 6G technologies. In the evolution from 5G to 6G, the incorporation of novel waveforms emerges as a pivotal consideration. While 5G's development was encumbered by material limitations, 6G signifies a phase of unconstrained exploration. A central tenet of 6G's objectives lies in augmenting spectral throughput, particularly for IoT applications. This trajectory may initiate with a transition from the prevailing orthogonal frequency-division multiplexing (OFDM) standards, thereby paving the path for potential migration towards universal filtered multi carrier (UFMC) for enhanced efficiency. Indeed, UFMC has several benefits for 6G applications. UFMC has better spectral efficiency, lower sensitivity to synchronization errors (compared to OFDM) [17], can be resilient to the Doppler effect in some cases [18], which is relevant for applications with mobility, and finally, has more flexibility in the filters used for pulse-shaping [19]. Taking into account the advantages of VLC and its growing interest for 6G combined with the promising future of UFMC for 6G, combining both seems a relevant study. To summarize, this paper presents the combination of VLC, which is a technology that has been foreseen as promising for 6G among optical wireless communication technologies [20], and UFMC. This study delves into the strategic utilization of visible light communication (VLC) as a means of short-range communication within urban and industrial environments. By concentrating on scenarios where ultra-high data rates are non-essential, the investigation explores VLC's pragmatic applications in optimizing communication resources.The prior research, such as studies examining VLC's efficacy in industrial automation or urban infrastructure monitoring, furnishes invaluable insights [21]. This study advances this domain by proposing a methodology for calculating indoor and outdoor VLC channels, augmenting the existing body of knowledge. Additionally, it offers a comprehensive suite of open-source tools for designing and simulating VLC scenarios, accessible via the Github platform. Leveraging these resources, the study advocates for simulating VLC communications in a tailored smart city scenario using the UFMC waveform, assessing performance metrics such as bit error rate and spectral efficiency. The promising outcomes position UFMC-VLC technology as a prospective component of future 6G systems. Through this endeavor, the study seeks to expedite the integration of VLC within the broader spectrum of 6G technologies, fostering an adaptive framework conducive to smart city and industrial applications.