The integration of satellite communication systems with terrestrial networks is emerging as a crucial solution to achieve seamless global connectivity in the evolving landscape of 5G and future 6G networks. A recent article published in Engineering titled "Evolution of Satellite Communication Systems Toward 5G/6G for 2030 and Beyond" provides a comprehensive overview of the advancements, challenges, and future directions in this domain.
According to the article, terrestrial networks (TNs) have made significant strides from 1G to 4G, and now 5G, in increasing communication speeds and improving quality of service. However, these networks face limitations in remote or sparsely populated areas due to geographical constraints, high deployment costs, and insufficient bandwidth. This is where satellite communication systems come into play, offering a promising solution to provide global coverage, low latency, and high throughput.
The authors highlight that satellite networks are becoming an integral part of future 5G/6G systems, combining with TNs to form a unified communication infrastructure. Satellites at various orbital altitudes—geostationary Earth-orbit (GEO), medium-Earth-orbit (MEO), and low-Earth-orbit (LEO)—serve different roles, such as access, forwarding, and relay nodes. For instance, GEO satellites are suitable for fixed satellite services with high latency, while LEO satellites offer low latency and are ideal for global broadband access and Internet of Things (IoT) connectivity.
Significant advancements have bridged the gap between satellite communication and TNs. High-throughput satellites, mega-constellations in LEO, and improved payloads with beamforming and onboard processing have reduced latency and increased capacity. The development of inter-satellite links (ISLs), particularly optical ISLs, has also been a game-changer, offering higher data rates and better interference immunity. However, challenges remain, including high deployment costs and the need for precise beam alignment in large-scale constellations.
The article also discusses the role of international standardization bodies such as the 3rd Generation Partnership Project (3GPP) and International Telecommunication Union (ITU) in facilitating the integration of satellite networks with TNs. 3GPP has released a series of technical reports and specifications to support non-terrestrial network (NTN) integration, with each release progressively enhancing the capabilities of satellite systems within 5G and future networks. For example, Release 17 marked the first time NTNs were incorporated as a core element within the 5G system architecture, supporting features like direct-to-device satellite links and IoT applications.
Looking ahead, the authors identify key challenges and potential research directions for satellite communication systems in 5G/6G. These include managing long propagation delays, high Doppler shifts, efficient resource management, dynamic beam coverage adaptation, mobility and handover management, and optimal routing and path selection. Future research may focus on leveraging technologies such as AI-driven network management, direct smartphone access to satellites, mega-LEO constellations, spectrum sharing, optical wireless communication, and reconfigurable intelligent surfaces.
The integration of satellite communication systems with terrestrial networks is a significant trend in the evolution from 5G to 6G. As research and development continue, addressing the identified challenges will be crucial to realizing the full potential of seamless global connectivity for future communication networks.
The paper "Evolution of Satellite Communication Systems Toward 5G/6G for 2030 and Beyond," is authored by Afang Yuan, Zhihua Yang, Zhili Sun. Full text of the open access paper: https://doi.org/10.1016/j.eng.2025.06.025
