Comparative Analysis of 3GPP and ITU-R 5G Channel Models

The design and validation of 5G systems rely heavily on standardized radio channel models to predict real-world performance. The 3GPP TR 38.901 and the ITU-R M.2412 reports are the industry’s cornerstones for this purpose, yet they exhibit significant technical differences, particularly in the sub-6 GHz frequency band and millimeter-wave indoor scenarios. This paper presents a rigorous comparative study of these two standards, quantifying the performance impact of their divergences across canonical deployment scenarios. Using a unified simulation framework implemented in ns-3, we analyze pathloss and Signal-to-Noise Ratio (SNR) in Rural Macro (RMa), Urban Macro (UMa), Urban Micro (UMi), and Indoor Hotspot (InH) environments. Our results reveal that while the models align in rural scenarios, they diverge fundamentally in complex urban environments. The ITU-R model proves to be a more conservative benchmark in UMa NLOS, predicting a median SNR up to 9.5 dB lower than 3GPP. Conversely, in UMi NLOS, the 3GPP model describes a significantly more volatile channel (higher shadow fading variance), making it a risky predictor for Ultra-Reliable Low-Latency Communications (URLLC). Furthermore, our analysis of the indoor 28 GHz scenario exposes a dramatic discrepancy: the ITU-R’s optional model is exceptionally optimistic, showing a performance gap of up to 34 dB compared to the standard 3GPP model. We conclude that these technical divergences reflect differing design philosophies – optimistic prediction vs. conservative benchmarking – dictating that model selection must be strategically aligned with the specific 5G service pillar (eMBB or URLLC) under evaluation.