5G Integrated Satellite Communication Systems: Architectures, Air Interface, and Standardization

The integration of satellite and terrestrial networks is a promising approach for future mobile communications to provide global coverage, seamless connectivity, and all-scenario services. However, the inherent characteristics of satellite communication (SatCom) systems pose challenges to the fulfilment of integrated satellite-terrestrial networks. In this paper, we provide an overview of the background on the evolution of SatCom networks. Based on the architecture options in non-terrestrial networks proposed by 3GPP, we discuss and analyze the key technical issues in network architecture, air interface, and standardization of 5G integrated SatCom networks. Finally, a comprehensive analysis of roadmap for satellite-terrestrial integration is also proposed.