Abstract
The global expansion of 5G and the anticipated rollout of 6G networks have intensified the demand for mid-band spectrum, particularly within the 4400–4800 MHz range. While the 4800–4990 MHz segment is already standardized for International Mobile Telecommunications (IMT), the 4400–4800 MHz sub-band remains under consideration by the ITU-R due to coexistence concerns with Fixed-Satellite Service (FSS) systems, especially those governed by Appendix 30B of the Radio Regulations. This study investigates the potential interference from 5G/NR base stations to FSS earth stations operating within 4500–4800 MHz using Monte Carlo simulation. Employing realistic deployment parameters and propagation models, the study evaluates long- and short-term interference across varying elevation angles and urban/suburban environments. The results indicate that while significant separation distances are required at very low elevation angles, the risk of harmful cross-border interference is minimal at typical operational angles. These findings support the feasibility of shared use of the 4400–4800 MHz band for 5G/NR without compromising FSS integrity.