Spectral Coexistence Between NGSO and GSO Satellite Systems: A Comprehensive Survey

Abstract

The rapid deployment of large-scale non-geostationary orbit (NGSO) constellations, such as Starlink, OneWeb, and Kuiper, is reshaping satellite communications by enabling worldwide low-latency connectivity. This expansion, however, raises coexistence challenges with legacy geostationary orbit (GSO) systems, particularly regarding harmful interference and compliance with International Telecommunication Union (ITU) regulations. In this context, we present a comprehensive survey of interference mitigation and detection strategies for NGSO–GSO coexistence. Non-cooperative approaches, including geometric methods, systematic techniques, and hybrid strategies, are discussed alongside cooperative frameworks based on cognitive radio, dynamic spectrum access (DSA), reconfigurable intelligent surfaces (RIS), and inter-satellite coordination. Advances concerning interference detection using machine learning and generative artificial intelligence (GenAI) are also highlighted as key enablers for real-time spectrum management. Furthermore, this paper identifies open challenges, such as scalability of ultra-large constellations, regulatory limits on single-entry interference from NGSO to GSO, and integration of regulatory and technical requirements. Future research directions should emphasize AI-driven spectrum sharing, sustainable space operations, and regulatory evolution to support next-generation multi-orbit satellite networks. By consolidating recent developments and outlining research opportunities, this work aims to guide the design of reliable, interference-resilient, and spectrum-efficient satellite communication systems.