Technology Roadmap Working Group: NTN Panel
The NTN Panel, hosted by the ATIS Next G Alliance’s Technology Roadmap Working Group on February 25, 2026, brought together experts from industry and academia to discuss the future of Non-Terrestrial Networks (NTN) in the 6G era. With participation from leaders across the information and communications technology ecosystem, including Ericsson, Qualcomm, Anritsu, Nokia, and University of Texas at Austin, the discussion explored technical evolution, standardization, spectrum strategy, and business models shaping the next decade.
6G and NTN
The panel agreed that 6G NTN will build upon 5G 3GPP Release 17/18 foundations but introduce major enhancements:
- There is strong momentum toward Low Earth Orbit (LEO) and Very Low Earth Orbit, with new constellations targeting altitudes as low as 300 km. 6G must be designed with these deployment realities in mind.
- Unlike early 5G NTN assumptions that leaned toward transparent payloads, 6G is expected to prioritize regenerative satellites (with onboard gNB functionality) alongside transparent architectures from the start.
- Satellite power constraints demand efficient waveform, coding, and protocol design. Therefore, “lean” NTN design is critical.
- Seamless TN-NTN integration. 6G aims to blur the line between terrestrial networks (TNs) and NTNs. The user should not perceive transitions from TN to NTN and vice-versa.
- Reducing reliance on GNSS is emerging as a key 6G NTN objective. Solutions require time-frequency pre-compensation without GNSS and may include:
- Reference-point-based synchronization
- LEO-based positioning
- Closed-loop time and frequency corrections
Standardized 3GPP-Based NTN
Among panel members, a strong consensus emerged in favor of standardized 3GPP-based NTN. While early deployments (e.g., pre-Release 17 systems) relied on proprietary solutions while still using LTE protocol stack in the device, major players, including SpaceX and AST Space Mobile, are now engaging in 3GPP standards development. Standards-based NTN solutions are essential because of:
- Global economies of scale
- Interoperability and roaming
- Certification framework
- Future proof evolution
- Device ecosystem alignment
- Guaranteed performance
However, Professor Todd Humphreys raised one nuanced perspective: proprietary systems may not currently suffer a large efficiency penalty if their beams are sufficiently narrow. The incentive to migrate to full NTN standards depends on measurable performance gains, particularly in uplink capacity, due to lack of Doppler compensation and the corresponding multiplexing efficiency.
The panel also discussed seamless mobility (i.e. transparent user mobility between TN and NTN and vice-versa). The consensus was that it is technically feasible to do so but with the following observations:
- LEO latency should be within tens of milliseconds
- Optimization and architectural requirements should be met
- Direct satellite–gNB connectivity could significantly improve the efficient use of shared spectrum.
GNSS Spoofing and Jamming
Next, the panel addressed GNSS spoofing and jamming which have elevated resilience concerns. Distinct challenges were identified:
- Spoofing
- Access without knowing location as NTN reliability needs its location to perform the doppler/timing pre-compensation
- Positioning using NTN signals. One promising direction is hybrid terrestrial–satellite, where communication signals themselves enable positioning is an integrated sensing and communications (ISAC) approach. However, sparse constellations and beam geometry constraints complicate NTN-based positioning in early deployments.
LEO vs GEO
The panel then focused on the orbital debate on LEO vs geostationary (GEO) satellites. As is evident, the LEO advantages are lower latency, higher signal strength, better integration with TN, and self-cleaning orbits (particularly for v-LEO). GEO, on the other hand, can have massive coverage with a single satellite and lower constellation complexity but suffers from very high latency. The consensus was that LEO, and potentially Medium Earth Orbit (MEO), will dominate long-term, especially as launch costs continue to decline. GEO may remain relevant for specific IoT or niche applications but faces latency limitations for real-time services.
Spectrum
Discussion also focused on NTN spectrum issues. Two models are emerging: i) Mobile Satellite Service (MSS) spectrum and ii) Terrestrial Spectrum. MSS has a cleaner regulatory environment, fewer border interference issues and is favored by the panelists. Reusing terrestrial spectrum for satellite communication works well in large countries like US and Australia but will be more challenging to implement in dense regions like Europe. It also requires careful interference co-ordination. The long-term view is that MSS spectrum likely remains more valuable for NTN, but NTN-terrestrial network spectrum sharing will grow as demand increases.
The panel also touched on the topic of time division duplexing (TDD) vs. frequency-division duplexing (FDD) for NTN. While FDD remains simpler and more link-budget friendly, some panelists suggested that long-term NTN evolution — especially using IMT bands — may require TDD support. Challenges include: i) long round-trip delays; ii) guard period inefficiency; iii) cross-link interference; and iv) tight synchronization requirements.
Large vs. Small Satellites
Finally, a lively debate compared a few large satellites (AST-style) and many small satellites (Starlink-style). Large satellites offer high power (e.g., 50 kW class), narrow beams and long lifetime, while smaller satellites offer lower latency, higher spatial reuse, faster deployment cycles and greater resilience. Both represent valid local optima. The winning architecture will depend on area spectral efficiency, economics and power distribution flexibility.
NTN in the 6G World: Delivering a Truly Unified Terrestrial and Non-Terrestrial Network
The panel revealed that 6G NTN is not about building a separate satellite network. It is about deep integration, standardization, resilience, and global scale.
The real breakthrough will come when:
- GNSS is optional
- Mobility is seamless
- Spectrum is flexibly shared
The industry is converging. 6G may finally deliver a truly unified terrestrial and non-terrestrial network.
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