High Resolution Radio Environmental Maps using Sionna Ray Tracing: The Case Study of Bologna

Accurate wireless network planning within historically complex urban environments poses unique challenges due to dense architectural configurations, diverse construction materials, and strict preservation regulations. Traditional propagation models like Free-Space Path Loss (FSPL), Okumura-Hata, and COST-231, although computationally efficient, significantly underestimate electromagnetic interactions inherent to these nuanced environments. This thesis explores the application of geometry-aware Ray Tracing (RT), specifically using the open-source Sionna RT framework, to generate high-resolution radio environmental maps for the city of Bologna a UNESCO Heritage Site characterized by narrow streets, extensive porticoes, and architectural diversity. Employing a detailed, open-source pipeline integrating Blender for 3D modeling and Mitsuba 3 with Dr.Jit for ray tracing, Bologna’s historical center was methodically segmented into ten precise 3D slices. Simulations considered realistic parameters such as received signal strength (RSS), channel impulse response (CIR), delay spread, and angle of arrival (AoA). Findings revealed significant spatial and temporal variability in signal propagation patterns. Unique phenomena, including waveguiding beneath porticoes and extensive diffraction in narrow alleyways, highlighted the inadequacies of classical models, which failed to capture these crucial dynamics accurately. The thesis validates the feasibility and effectiveness of CPU-based Sionna RT simulations, providing a robust, reproducible framework for urban wireless analysis. Its outcomes deliver crucial insights and practical guidelines for deploying 5G and IoT infrastructures in heritage cities, balancing technological advancement with urban preservation demands.