As global connectivity becomes more essential to every aspect of life and industry, extending 5G coverage to areas where terrestrial networks cannot reach is one of the next major frontiers.
That’s where 5G Non-Terrestrial Networks (NTN) come in.
A white paper published by Rohde & Schwarz provides a thorough technical overview of this emerging landscape, offering insights into how satellite communication is being integrated into the 5G ecosystem, the challenges involved, and the solutions being implemented.
In this article, we’ll break down the key elements of the white paper, summarize its most important findings, and comment on how RCATSONE is at the forefront of 5G NTN testing and validation.
What Are 5G Non-Terrestrial Networks (NTN)?
5G NTN refers to the integration of satellite and high-altitude platforms into the standard 5G network infrastructure. The goal is to provide coverage to underserved areas such as rural communities, oceans, disaster zones, and in-flight or maritime scenarios where ground-based cellular infrastructure is impractical or impossible.
The 3GPP (Third Generation Partnership Project), the global body behind mobile communication standards, formally introduced NTN support in Release 17 of the 5G standard, with further enhancements expected in Release 18 and beyond.
Types of NTN Architectures
The paper outlines two major NTN configurations:
- Transparent Payloads (Bent-Pipe)
These systems act as relays between a ground-based gateway and end-user devices, forwarding signals without processing them. While simpler, this model depends heavily on ground infrastructure and is more vulnerable to latency issues. - Regenerative Payloads
Here, the satellite itself performs some baseband processing. This architecture offers lower latency, higher reliability, and reduced dependence on Earth-based infrastructure—ideal for deep-sea or polar regions.
Key Use Cases for 5G NTN
The authors describe a broad range of applications that benefit from NTN technology:
- Rural and remote broadband access
- Emergency communications and disaster recovery
- IoT in agriculture, mining, and energy
- Direct-to-handset connectivity
- Mobility services for aviation and maritime industries
These use cases make clear that NTN will not only complement terrestrial networks but also unlock entirely new business and connectivity models.
Technical Challenges of 5G NTN
Integrating satellite technology into the 5G framework introduces several significant technical hurdles:
- Propagation Delay and Doppler Shift:
The distance between satellites and ground terminals (especially for GEO satellites) introduces substantial latency and frequency shifts that traditional 5G systems weren’t initially designed to handle. - Channel Modeling:
The variation in signal paths due to atmospheric conditions, terrain, and satellite motion makes precise modelling of signal behaviour extremely complex. - Timing and Synchronization:
Synchronizing timing signals across a constantly moving satellite network is much more difficult than with fixed terrestrial towers. - Link Budget Constraints:
Transmitting across space introduces much higher path loss, meaning power constraints and antenna gain become critical factors.
Solutions Introduced in 3GPP Release 17
To tackle these obstacles, 3GPP’s Release 17 introduced multiple enhancements to existing 5G protocols, such as:
- Enhanced random access procedures for longer signal delays
- Modified reference signals to manage Doppler effects
- Custom waveforms and coding schemes to boost resilience
- Support for extended cyclic prefixes to accommodate propagation delay
These improvements pave the way for stable communication in LEO (Low Earth Orbit), MEO (Medium Earth Orbit), and GEO (Geostationary Orbit) satellite constellations.
Testing and Validation: The Cornerstone of 5G NTN Deployment
The white paper from Rohde & Schwarz emphasizes that testing is not a one-size-fits-all process for NTN. Different orbital regimes and payload types require unique validation approaches, particularly in emulating real-world Doppler, delay, and channel conditions.
Test solutions must support both the physical (RF) layer and higher-layer signaling protocols to ensure performance, reliability, and compliance with 3GPP standards.
This is where companies like RCATSONE are making a significant impact.
RCATSONE’s Role in 5G NTN Advancement
RCATSONE provides comprehensive, real-world testing environments for mobile and satellite communications.
As 5G NTN grows, RCATSONE is leveraging its deep expertise in end-to-end network testing, helping satellite operators and mobile carriers validate:
- Coverage quality across remote regions
- NTN-device interoperability
- Propagation modelling under extreme conditions
- Seamless handovers between terrestrial and satellite links
Their platform simulates real-world use cases providing data-driven insights that accelerate deployment and reduce risk.
By collaborating with OEMs and satellite vendors, RCATSONE is ensuring that 5G NTN isn’t just a theoretical promise, but a reliable, high-performance reality.
Looking Ahead: What’s Next for 5G NTN?
The white paper concludes by highlighting the potential of NTN beyond Release 17. Future developments include:
- 6G integration, where satellite systems will play an even more central role
- Dynamic spectrum sharing between terrestrial and non-terrestrial systems
- Massive IoT deployments powered by low-power, wide-area NTN links
- Enhanced AI-driven orchestration for autonomous resource management across land, sea, air, and space
The continued convergence of terrestrial and satellite technology will transform how the world connects—from remote villages to high-speed jets.
Where to from here?
As I see it, the progress within 3GPP Release 18 marks a major evolution of non-terrestrial networks (NTN) in the 5G landscape.
Building on the groundwork laid by Release 17, Release 18 expands NTN capabilities beyond initial transparent-mode architecture and low-frequency operations. The focus is on more advanced and efficient features for both standard 5G NR and IoT-specific NTN services.
What’s especially exciting is the push for improvements across the board—better feeder link capacity, more power-efficient user devices, cost-effective user terminals (like VSATs), and smaller, more agile satellite designs. We’re also seeing serious work on enabling NTN operation over higher frequencies like the Ka and Ku bands and even exploring new frequency ranges.
There’s a growing interest in regenerative satellite architecture, where satellites gain onboard processing power. Over time, these satellites may behave like autonomous base stations (gNBs), rather than simply relaying signals back to earth.
Another advancement is removing the requirement for user devices to rely on positioning systems like GNSS. Release 18 supports new methods allowing networks to localize devices directly. We’re also seeing developments in handovers between NTN and terrestrial networks, dual connectivity, and coverage enhancements that could even support voice services over satellite.
For IoT, Release 18 aims to lower power consumption, improve GNSS efficiency, and handle discontinuous coverage more intelligently. It introduces energy-saving features like conditional re-establishment, optimized RRC procedures, and even “store and forward” behavior. In this setup, one IoT device can collect and forward data for others, striking a balance between power usage and coverage availability.
From my perspective, Release 17 was a foundational step, proving that integrating satellites into 5G is not only feasible but necessary to reach underserved areas. Satellites provide unmatched value in regions where laying terrestrial infrastructure is impractical—rural zones, oceans, disaster-stricken areas. As governments begin to view connectivity as vital as utilities like electricity and water, the relevance of NTN becomes undeniable.
Despite latency challenges due to the distance between users and satellites, technologies like high-altitude platforms (HAPS), onboard processing, and edge computing will help minimize these limitations. True, we won’t match the responsiveness of indoor small-cell setups, but that’s not the goal—our focus is broad, reliable, resilient coverage.
To me, NTN is more than an enhancement. It represents a paradigm shift—where the “base station” itself moves through space. This challenges many traditional assumptions in telecom engineering. The concept of dynamic, floating, and intelligent networks—especially in how resources are managed and how coverage is maintained—signals a bold new chapter.
The journey from Release 17 to Release 18 is the start of a transformation in how we think about wireless communications. It blends terrestrial and satellite systems into one cooperative ecosystem, and RCATSONE is proud to support this with our ongoing innovation in testing, measurement, and mobile experience assurance.
