AraOptical Testbed: Design, Field Trials, and Channel Analysis of Long-Range FSOC System With COTS Transceivers

This paper presents araoptical, a 10.15 km rural free-space optical communication (FSOC) testbed designed using commercial off-the-shelf (COTS) 10 G SFP+ transceivers and integrated into the ARA wireless living lab. The system features a multi-level autonomous alignment algorithm and real-time link monitoring, enabling stable high-throughput communication in dynamically varying atmospheric conditions. A continuous 2-hour UDP-based bit rate test was conducted, and environmental data were logged to investigate turbulence-induced impairments. A two-stage polynomial regression approach was developed to estimate the refractive index structure parameter ($C_{n}^{2}$) from weather station data and predict link throughput by combining one-minute block-averaged received power with the Rytov variance predicted from the measured meteorological data. The proposed model achieved$R^{2} = 89.92\%$for turbulence estimation and$R^{2} = 62.22\%$for throughput prediction. Our results demonstrate the feasibility of using in-situ environmental sensing and data-driven models to characterize and predict FSOC performance under real-world conditions.