Verification of Communication Parameters for NTN Communication

Abstract

Non-terrestrial networks (NTNs) are envisioned to extend 5 G coverage globally, with Narrowband IoT (NB-IoT) identified as a key technology for massive machine-type communication in remote or underserved areas. Accurate modeling of the satellite channel is crucial to assess reliability and system performance. This paper presents a comparative study of two widely used NTN propagation models: the ETSI Rician fading model and the ITU-R P. 681 land mobile-satellite model. Using MATLAB simulations of the NB-IoT NPDSCH link in a LEO 1200 km scenario, we evaluate block error rate (BLER) performance across elevation angles from 0° to 90° with varying numbers of repetitions. Results demonstrate that the ETSI Rician model, while simple and analytically tractable, produces overly optimistic BLER predictions at low elevations. In contrast, the ITU-R P. 681 model proved to be more versatile and capable of capturing diverse propagation environments. These findings highlight the importance of model selection for NTN design, particularly in low-elevation and urban scenarios.