Abstract
Several satellite services, including the Fixed Satellite Service (FSS), rely on the C-Band (3. 4 – 4. 2 GHz), which provides wide coverage and high availability despite weather effects. As a mid-band spectrum ideal for 5G, its allocation to cellular networks raises interference concerns, potentially disrupting satellite services and causing a significant economic impact. This study presents an empirical, measurement-based 5G propagation assessment and an interference investigation with 5G cellular networks operating below the 6 GHz band in the optimization of exclusion zones for 5G and FSS scenarios, with the aim of fine-tuning the exclusion zone and identifying better coexistence conditions between the two systems. We provide an extensive 5G-cellular downlink analysis that discusses, as part of the coexistence context, the potential for Low-Noise Block (LNB) saturation at the FSS Earth station receiver. Moreover, we deployed a real indoor 5G cellular network for measurement, in which high-gain receiving antennas were positioned at various indoor and outdoor locations to capture the downlink signal radiated by the 5G base-station transmitter within the proposed site. Additionally, a spectrum analyzer was used to examine the power signal received in contrast to the data signal acquired for the proposed projects. Across the indoor measurement points, the received power decreased with distance, reaching approximately −74.02 dBm at 40 m, and no measurable elevation of the FSS signal was observed at the MEASAT earth station located 3 km away. The results of this research indicate that spectrum regulators and other relevant parties will be affected by the potential implementation of 5G cellular networks in C-band operational FSS Earth station receivers. The research additionally proposes and evaluates methods that could facilitate the harmonious coexistence of both systems, like disabling significant emitters or diminishing their transmission capacity.