Sionna™ is an open-source, GPU-accelerated library that, as of version 0.14, incorporates a ray tracer, Sionna RT, for simulating radio wave propagation.A unique feature of Sionna RT is differentiability, enabling the calculation of gradients for thechannel impulse responses (CIRs), radio maps, and other related metrics with respect to system and environmental parameters, such as material properties, antenna patterns, and array geometries.The release of Sionna 1.0 provides a complete overhaul of the ray tracer, significantly improving its speed, memory efficiency, and extensibility.This document details the algorithms employed by Sionna RT to simulate radio wave propagation efficiently, while also addressing their current limitations.Given that the computation ofCIRs and radio maps requires distinct algorithms, these are detailed in separate sections.ForCIRs, Sionna RT integratesshooting and bouncing of rays (SBR) with the image method and uses a hashing-based mechanism to efficiently eliminate duplicate paths. Radio maps are computed using a purelySBR-based approach.

Citation

@article{sionna-rt-tech-report,title={Sionna RT: Technical Report},author={{Aït Aoudia}, Fayçal and Hoydis, Jakob and Nimier-David, Merlin and  Nicolet, Baptiste and Cammerer, Sebastian and Keller, Alexander},year = {2025},month = {Nov},journal = {arXiv:2504.21719},url = {https://arxiv.org/abs/2504.21719}}