A Q&A with Middle Wen

Non-terrestrial networks (NTNs) are evolving rapidly, propelled by advances in low Earth orbit (LEO) satellites, high-altitude platform stations (HAPS) and ongoing integration with 5G and emerging 6G standards. As these technologies mature, they promise to deliver resilient, high-capacity connectivity to places and applications that have traditionally been beyond the reach of terrestrial networks.

A new generation of NTNs is reshaping expectations for coverage, latency and bandwidth while opening the door to direct-to-smartphone services, mission-critical applications such as telemedicine and defense communications, and cost-effective backhaul for rural 5G deployments. 

To keep pace, hardware designers are exploring innovations in antenna arrays, RF front ends and low-power electronics to reduce the size and cost of NTN-enabled devices. Testing solutions must also advance, enabling realistic emulation of orbital dynamics, rigorous handover verification, and support for both standardized and proprietary protocols.

In this Q&A, LitePoint’s Middle Wen discusses practical considerations – from network architecture and spectrum policy to device design and the next-generation test methodologies essential for deployment– that are shaping the future of NTN technology.

Q: How are LEO satellite constellations and HAPS platforms influencing NTNs?

Middle: LEO and HAPS are driving a shift toward more dynamic, flexible NTN architectures. LEOs offer low-latency, high-throughput connectivity, while HAPS provide localized coverage with rapid deployment. Together, they enable hybrid architectures that combine persistent global coverage with targeted service delivery – ideal for disaster recovery, rural connectivity and Internet of Things (IoT) networks.

Q: How is the convergence of NTNs and terrestrial 5G influencing the build-out of global networks, and what impact will 6G networks have?

Middle: By 2035, it’s plausible that we’ll see some form of unified global network standard, especially as 3GPP continues to integrate NTN specifications (e.g., Release 17 and beyond). At the same time, however, proprietary systems may still dominate sectors like defense, maritime and private enterprise networks, where customization and control are prioritized over interoperability.

The arrival of 6G is expected to bring ultra-low latency (<1 ms), massive bandwidth and AI-native orchestration. Expect NTN to play a key role in ubiquitous coverage and resilient connectivity by extending these capabilities to remote and mobile environments. But challenges remain in managing latency variability across orbits and ensuring QoS. 

Q: What role will AI-driven network orchestration play in optimizing NTN performance for real-time applications?

Middle: AI will be central to real-time beam steering, dynamic spectrum allocation and predictive handovers. Machine learning models can optimize NTN link performance based on user mobility, weather conditions and traffic patterns. This is crucial for applications like autonomous vehicles and remote surgery.

Q: These AI-driven efficiencies are key for enabling the next generation of high-value NTN applications. How will direct-to-smartphone NTN services reshape mobile broadband in underserved regions, and what new mission-critical services will emerge?

Middle: Direct-to-device NTN services (e.g., via 3GPP Rel-17 NR NTN) will democratize mobile broadband access, especially in remote regions. This could disrupt traditional mobile markets by reducing reliance on terrestrial infrastructure and enabling new service models like pay-as-you-go satellite data. As this happens, more cost-efficient NTNs will unlock important new use cases:

• Telemedicine can employ real-time diagnostics and remote surgery in isolated areas.
• Defense networks can provide secure, resilient communications in contested environments.
• Precision farming can increase crop yields with real-time sensor data and drone coordination.

In addition, NTNs could replace fiber in rural 5G deployments, offering scalable, cost-effective backhaul. This is especially viable with LEO constellations providing high-capacity links and HAPS offering localized aggregation points.

Q: What do designers need to know as they look to more broadly deploy NTNs? 

Middle: Designers must account for varying Doppler shifts, link budgets and handover logic across GEO, MEO and LEO installations. Multi-orbit support requires agile RF front-ends and adaptive protocol stacks. Spectrum harmonization is also a major hurdle. Designers must navigate ITU allocations, national licensing and regulatory requirements and manage coexistence with terrestrial services, especially in the Ka- and S-bands.

Designers must also enable seamless roaming between NTN and terrestrial networks, which demands unified signaling, authentication and mobility management. Dual-mode chipsets and standardized APIs will be key here. Another looming design issue is the expected proliferation of NTN form factors based on anticipated improvements in phased-array antennas, RF front-end design and low-power ASICs. Miniaturized RF components will reduce device size and cost and enable new level of NTN integration into smartphones, wearables and IoT nodes.

Q: What test protocols are important, and which methodologies will be most effective for handing off communications between satellites, NTNs and terrestrial 5G networks?

Middle: To simulate real-world conditions, test systems must emulate orbital dynamics, Doppler shifts and latency profiles. This includes satellite motion models and link variability across GEO, MEO and LEO. To enable seamless handover verification, effective methodologies include hardware-in-the-loop (HIL) testing, protocol emulation and multi-band RF testing. Operation in the sub-3 GHz and Ka-bands requires a distinct approach due to propagation differences.

Q: What adjustments to 5G test solutions are needed to accommodate proprietary NTN protocols, and how can test automation be applied to accelerate compliance with both NTN protocols and 3GPP Release-17+ standards?

Middle: To accommodate proprietary protocols, test solutions must be modular and extensible to support private stacks while maintaining 3GPP compliance. This includes protocol abstraction layers and customizable test scripts. To ensure test automation compliance, automation frameworks can accelerate validation against evolving standards. Here, AI-driven test orchestration and cloud-based simulation environments will be increasingly important.

Q: Are there other test considerations to remain aware of?

Middle: There are several, and one of the most important for operators and designers is environmental testing, which includes testing for radiation levels and temperature extremes. Two others are security validation to ensure encryption and jamming resistance, and QoS benchmarking across heterogeneous networks.

In the end, wireless testing is essential for reliable NTN deployment because it validates performance under real-world orbital conditions – before systems go live. By accurately emulating satellite dynamics, Doppler shifts and complex spectrum environments, testing ensures devices, networks and protocols deliver consistent connectivity, security and QoS across space and terrestrial domains.