Dual-purpose VLC for water quality sensing and underwater adaptive communication

Underwater networks are increasingly critical for modern infrastructure, enabling environmental monitoring, submerged robotics, and coastal surveillance in resource-constrained aquatic environments. This work proposes a dual-purpose Visible Light Communication (VLC) framework that concurrently monitors water turbidity and enables adaptive optical communication. By leveraging software-defined control of multi-wavelength LED arrays, the system dynamically optimizes transmission channels to mitigate turbidity-induced signal degradation while providing real-time water quality feedback. The experimental results demonstrate a low error (around 10%) in turbidity estimation and robust short-range data transmission under ambient interference. The scalability and cost efficiency of the architecture address key challenges in underwater IoT deployments, offering a practical solution for metropolitan-scale applications such as smart water grids and environmental conservation.