Automated city scale digital twins improve urban radio signal predictions
KODAMA: Multimodal Digital Twin Reconstruction for Urban RF Propagation Modelling
Computer Vision and Pattern Recognition
Summary
Predicting how radio waves travel through cities helps improve wireless communication but usually requires either rough automated maps or detailed models that take weeks to build. The authors present KODAMA, a system that uses public data like aerial photos and street images to automatically create detailed 3D city models for radio wave simulations without needing physical visits or adjustments. Their models closely match measurements from hand-made site models, making it easier and faster to predict radio signals in urban areas. This could help with better planning of wireless networks in cities.
radio frequencydigital twin3D reconstructionray tracingurban propagationLiDARphotogrammetrygeospatial datawireless communicationchannel prediction
Authors
Maximiliano Wardle, A. Ryo Koblitz
Abstract
3D reconstruction typically strives for geometric fidelity or visual plausibility. Radio frequency digital twins (RFDT) are instead judged by whether communication channels behave in them as they do in the real world. RFDTs promise site-specific channel prediction but current practice forces a choice between coarse automated scenes and hand-built, measurement-calibrated models that take weeks to construct per-site. We present KODAMA, an automated pipeline that reconstructs ray tracing-ready RFDTs at city scale from off-the-shelf geospatial data alone: aerial imagery, LiDAR, and photogrammetry yield terrain and watertight building meshes, while exposure-weighted multi-view fusion of street-level imagery recovers façade relief, electromagnetic materials, and clutter---all without site visits or calibration. Across three sites spanning 3.6 to 28 GHz, KODAMA's uncalibrated predictions achieve single-digit RMSE, reducing point-to-point error by up to 5.35 dB over automated baselines and coming within 0.22 dB of a measurement-calibrated, hand-built RFDT.