Emerging NGSO constellations: spectral coexistence with GSO satellite communication systems

The rapid expansion of Non-Geostationary Satellite Orbit (NGSO) constellations is reshaping satellite communications, creating complex interference scenarios with Geostationary Satellite Orbit (GSO) systems due to shared spectrum usage. This article explores the challenges of NGSO–GSO spectral coexistence, focusing on recent regulatory developments, including the World Radiocommunication Conference (WRC-23), which upheld existing EPFD limits while launching technical studies on aggregate interference. We review state-of-the-art mitigation strategies, such as beamforming and power control, validated through simulations, and highlight the role of AI in enhancing interference detection and response. The paper concludes with a forward-looking research agenda centered on adaptive regulatory tools, probabilistic interference models, and data-driven coordination to support sustainable orbital spectrum sharing.