NB-IoT for Direct-to-Satellite Communications: Performance Modeling and Evaluation

The rapid growth in Internet of Things (IoT) applications has driven demand for ubiquitous connectivity, reaching beyond terrestrial networks to include satellite communication solutions. This paper investigates the application of Narrowband IoT (NB-IoT) within Non-Terrestrial Networks (NTNs), specifically focusing on direct-to-satellite (DtS) communications for IoT in Low Earth Orbit (LEO) constellations. This study first provides an overview of NB-IoT's protocol adaptations required for NTN use, followed by the introduction of an analytical model for network throughput that incorporates the dependence on key system parameters, such as satellite velocity, spot size, and ground node density. Our results analyze key NB-IoT parameters affecting network performance, providing insights on configuration strategies to optimize connectivity for remote IoT deployments via LEO satellites. The findings contribute to understanding the feasibility of NB-IoT for DtS communication, highlighting practical considerations and performance trade-offs for deploying IoT over NTN.