From 5G to 6G non-terrestrial networks (NTN)

How 3GPP’s work on 5G NTN is changing global connectivity

What are non-terrestrial networks?

Non-terrestrial networks (NTN) are wireless communication systems that operate above the Earth’s surface. They include high-altitude platforms (HAPs), drones, and satellites in low Earth orbit (LEO), medium Earth orbit (MEO) and geostationary orbit (GEO).

The benefit of NTNs is that they can provide extended global communication coverage also to remote or underserved areas. They’re able to fill the connectivity gaps left by traditional terrestrial networks, which makes them essential for, e.g. emergency and critical communications.

Terrestrial networks (TN), on the other hand, are wired or wireless communication systems that rely on ground-based infrastructure, such as cell towers and fiber-optic cables. Traditional telecommunications are based on these networks, including mobile networks (e.g. 4G and 5G), broadband internet, and radio/TV broadcasting.

What is the 3GPP and what does it do?

The 3rd Generation Partnership Project (3GPP) develops standards for mobile telecommunications technologies such as radio access, core network and service capabilities. 3GPP standards are structured as Releases, but most people know them as mobile system generations, such as 2G, 3G, 4G and 5G.

The 3GPP is now working on standards for 5G technology, such as 5G non-terrestrial networks. The goal is to integrate satellite communication with terrestrial networks to improve global connectivity and coverage.

5G NTN aims to fill the coverage gaps of TN, extending connectivity also to remote and hard-to-reach areas, such as seas, mountains and deserts. Additionally, NTNs serve as a backup in the case of terrestrial network failures, for example, as a result of a natural disaster or emergency. This ensures that communication can continue even in these critical situations.

Magister has been working with the 3GPP throughout this process. We are happy to be able to share our competence in system simulations and help build the future of the SatCom industry through standardization – and there is still a lot to come. 

3GPP Releases enhancing NTN operation and coverage 

The 3GPP’s work on NTN started in 2018 with Release 15. Releases 15 and 16 focused on studying the NTN channel model, deployment scenarios, and minimum required adaptations for the existing 5G system to support NTNs.

Release 17 was the first official release that supported NTN for FR1 and handheld devices. Release 18, in turn, targeted to enhance the capabilities of NTN operation for above 10 GHz frequency bands (FR2) for VSAT terminals.

Release 19 is scheduled to be released at the end of 2025. Its objective is to provide improved coverage and optimized capacity, multicast and broadcast services (MBS), regenerative payload, and support for Reduced Capability (RedCap) terminals.

The road to 6G NTN can already be seen

After Release 19, the focus starts to shift towards 6G, which is expected to be a bigger leap. 3GPP studies for 6G are expected to begin from Release 20 in 2025. After that, from Release 21 in 2027, begins the normative work for 6G.

The integration of 6G and NTN/TN is already being investigated through different projects, such as the 6G SNS-funded 6G NTN, and Horizon Europe project NexaSphere.

The 6G NTN project aims to design and validate NTN’s key technical, regulatory and standardization enablers for the integration of terrestrial (TN) and NTN components into 6G. The objective is to build a unified TN and NTN system, with the design created for both environments from the start.

NexaSphere is exploring 6G and TN/NTN innovation, with the goal of designing a multi-connectivity system that unified radio, optical wireless and standard interfaces in indoor and outdoor environments, and related routing and forwarding algorithms. NexaSphere’s vision unifies TN/NTN for aviation, automotive and train connectivity.

Magister provides simulations for 5G & 6G NTN standardization

Magister has been actively involved in 5G NTN standardization work through projects with the European Space Agency.

One of our focus areas has been to provide system simulation support for NTN standardization needs. As a member of the 3GPP, we’ve contributed valuable simulation results to the global standardization process:

• We participated in Rel-17 NR-NTN standardization through the ALIX project.
• In the MARINA project, we contributed valuable insights about 5G-NR when operating in GEO High Throughput Satellite scenarios, influencing 3GPP standardization in Rel-18 and beyond.
• We participated in Rel-18 NR-NTN standardization through EAGER and 5G-SPECTRA projects, offering simulation support and research on TN/NTN adjacent channel coexistence on Frequency Range 2 (FR2) for RAN4.
• We’ve continued our active 3GPP standardization support work within the HELENA project. The project focuses on Rel-18 implementation and Rel-19 planning.
• We’re identifying required modifications to the current 3GPP specifications for having an efficient control plane fit to be deployed on Non-Terrestrial Networks as part of the NTN-CPD project.
• We’re currently working on the 5G-EMERGE project, which aims to integrate satellite technology into 5G networks. The goal is to develop critical technologies, such as Direct to Device (D2D) using 3GPP NR-NTN satellite technology.
• Within NexaSphere, we participate in the design of future 6G systems, in particular the integration between TN and NTN.

Through these projects, we have gained in-depth knowledge of 5G & 6G TN/NTN development and simulative evaluation. We can utilize this expertise in further helping our customers, and truly having an impact in future SatCom technologies.