Robust Global Connectivity through the Integration of NTN and Cellular Technologies

Terrestrial cellular networks provide reliable coverage in many regions, but their reach is limited in rural, remote, and maritime areas, as well as across certain continents where LTE-M or NB-IoT infrastructure is sparse or absent. In such cases, building new terrestrial networks often has low economic viability, leaving coverage gaps that can hinder applications such as asset tracking, environmental monitoring, and infrastructure management on a global scale. Non-Terrestrial Networks (NTN) address these limitations by extending 3rd Generation Partnership Project (3GPP)-standardized Narrowband IoT (NB-IoT) services to satellites. This integration allows IoT devices to connect through space-based networks when terrestrial coverage is unavailable. 

This article discusses how integrating NTN with terrestrial cellular technologies can close connectivity gaps, the role of Nordic Semiconductor’s nRF9151 SiP module in enabling hybrid operation, and the technical considerations for implementing such solutions.

What is NTN?

NTN refers to satellite-based cellular IoT connectivity, defined in the 3GPP standards from Release 17 through Release 19. The concept extends NB-IoT operation beyond terrestrial infrastructure by using satellites to connect devices in locations where ground-based networks are unavailable. Devices can connect to NTN in much the same way they roam between terrestrial operators, using the same SIM, and cloud services, provided their mobile network operator (MNO) or virtual MNO (MVNO) has roaming agreements with NTN providers.

GEO and LEO Satellite Constellations

NTN can operate over both geostationary (GEO) and low Earth orbit (LEO) constellations. GEO satellites remain fixed relative to a point on Earth by orbiting at approximately 36,000 km. This constant position ensures a stable link with continuous visibility from the coverage area. These satellites connect directly to Earth stations, which then route data to the cloud, resulting in relatively high end-to-end latency for the data transfer. However, because of the long distance and the associated link budget constraints, GEO systems typically offer low data rates and require longer device connection times, which impact power consumption. 

On the other hand, LEO satellites orbit at altitudes of roughly 500-1000km and, due to the low orbit, move quickly across the sky, with each orbit lasting around 90 minutes. Their shorter distance to Earth enables easier link budgets, higher potential data rates, and reduced connection times for devices. In fully deployed LEO constellations with direct backhaul, latency can be low, supporting near-real-time communication. However, in early-stage networks with limited satellites and ground stations, coverage is intermittent, and data traffic relies on a store-and-forward method. In this mode, information is uploaded to the satellite when a device is within range and later transmitted to a ground station, resulting in latencies that can range from several minutes to over an hour. As more LEO satellites are deployed and ground infrastructure expands, these delays are expected to decrease significantly. 

Core NTN Characteristics

NTN networks use licensed spectrum, similar to terrestrial LTE-M and NB-IoT, to ensure predictable performance and regulatory compliance. The long transmission distances, particularly in GEO systems, result in higher latency compared to terrestrial networks. In LEO systems without complete coverage or backhaul infrastructure, store-and-forward is used as a transitional approach, enabling basic connectivity until the network can support continuous coverage and real-time operation. While this approach ensures data eventually reaches its destination, it is best suited for applications that do not require immediate response times.

Nordic’s Role in Bridging NTN and Terrestrial Connectivity

Nordic Semiconductor’s nRF9151 module is designed to operate either exclusively on terrestrial networks or in a hybrid mode that combines terrestrial and NTN access. The choice of LTE stack firmware determines this flexibility. The NTN-enabled LTE stack supports LTE-M, NB-IoT, GPS, and NTN connectivity, enabling it to operate in both terrestrial networks as well as GEO and LEO satellite constellations.

The NTN-enabled LTE stack allows developers to design devices that use terrestrial LTE-M where coverage is available, and switch to LEO or GEO satellite connectivity in areas without terrestrial infrastructure. This approach makes use of existing terrestrial networks for efficiency and cost-effectiveness, reserving satellite links for situations where ground-based connectivity cannot be maintained.

Actual network access depends on the roaming agreements supported by the SIM in use. Many MVNOs are establishing arrangements with multiple NTN providers, enabling IoT devices to connect across a broader set of satellite constellations. This means a single hardware platform can adapt to different deployment regions and service availability without requiring hardware redesigns.

From a product lifecycle perspective, IoT deployments often operate in the field for many years, and network availability can change over that time. The nRF9151 enables developers to build long-lifecycle products that remain functional as terrestrial networks evolve or as new NTN services become available, by supporting features such as SGP32 for remote SIM provisioning.

The hardware for the nRF9151 is already available, and the early version of the NTN-enabled LTE stack is planned for release in the fourth quarter of 2025. This timeline allows developers to begin hardware integration now and prepare for adopting NTN once the firmware is released. In doing so, Nordic offers a single, adaptable hardware platform that supports today’s connectivity needs and can be upgraded to meet future network requirements.

Satellite-Driven Applications that Benefit from Hybrid Connectivity

Hybrid connectivity allows devices to switch between terrestrial and satellite networks as needed. Several application areas benefit from this capability.

Asset Tracking and Logistics

Uninterrupted connectivity is essential for maintaining visibility over shipments in industries that manage goods across long and varied transport routes. Hybrid NTN and terrestrial systems enable continuous monitoring in regions where LTE-M or NB-IoT coverage is lacking, such as remote areas in Africa, parts of South America, or maritime routes across open seas. Devices can use terrestrial networks where available, automatically switching to satellite links in coverage gaps. This ensures consistent location reporting, condition monitoring, and operational oversight for cross-border or intercontinental logistics.

Smart Agriculture and Forestry

Agricultural and forestry operations often extend across vast areas far from urban infrastructure, making continuous network access challenging. Hybrid connectivity allows the deployment of sensors and monitoring equipment in isolated fields, rangelands, or forested regions without the need to build dedicated local infrastructure. Applications include tracking soil moisture, monitoring crop or tree health, and collecting environmental data for yield optimization or conservation planning. 

Energy Infrastructure Monitoring

Energy networks frequently span remote or inhospitable environments, such as oil pipelines crossing wilderness regions or power transmission lines running through lightly populated areas. In such locations, terrestrial coverage may be absent or inconsistent. Hybrid NTN and terrestrial connectivity enable automated systems to maintain operational oversight, detect faults, and report performance data in near real-time, where possible. This capability reduces the need for physical inspections and supports faster incident response.

Disaster and Emergency Response

In disaster scenarios, terrestrial networks can be damaged or completely offline due to events such as earthquakes, floods, or hurricanes. Hybrid connectivity provides an additional communication pathway, enabling critical systems and responders to maintain coordination. Devices and sensors can switch to satellite communication when terrestrial infrastructure is unavailable, supporting activities such as locating stranded individuals, monitoring environmental hazards, and managing resource allocation. This redundancy helps sustain essential communication links during the most critical periods of recovery and relief operations.

Technical Challenges and Considerations

Designing devices that operate across both TN and NTN presents several technical hurdles, particularly in antenna performance, interference management, and power efficiency.

Antenna Design Across a Wide Frequency Range

Supporting both TN and NTN requires antennas that can operate effectively across a broad spectrum, typically from 700 MHz to 2.2 GHz. NTN frequency bands, especially in the L-band and S-band, are a critical part of this range. Achieving consistent performance across it is challenging, particularly for compact devices with embedded antennas, where physical space limits antenna size and efficiency. The problem is more pronounced for L-band operation because it sits farther from the standard LTE-M or NB-IoT terrestrial bands, often necessitating different antenna design considerations. A practical approach for many deployments is to optimize performance for the relevant NTN bands and only the most important TN bands in the target region. Antenna manufacturers are actively developing solutions to improve performance across this wide range, but for now, trade-offs between size, coverage, and efficiency remain.

GNSS Interference in the L-Band

Some NTN frequency allocations in the L-band sit close to GNSS signals, particularly the B1 band. This proximity increases the risk of interference, which can degrade satellite positioning performance. In the nRF9151, this issue is addressed at the system level. The module’s design ensures that GNSS and NTN operations do not occur simultaneously. The firmware manages time-multiplexing between the two functions, so when NTN communication is active, GNSS reception is temporarily paused, and vice versa. This built-in scheduling eliminates the need for developers to manage coexistence manually and ensures reliable operation for both communication and positioning functions.

Power Consumption in NTN Operation

A common assumption is that NTN operation always consumes more power than terrestrial connectivity. This holds when comparing NTN with devices operating under ideal or optimal terrestrial coverage. The situations where NTN becomes important are typically at the edge of terrestrial coverage or in areas with no coverage at all.

For instance, at the edge of terrestrial networks, devices may spend considerable energy maintaining a weak connection, as the LTE stack uses extended range mechanisms to compensate for poor signal quality. These same mechanisms are employed in NTN connections, meaning that the device’s power consumption in such terrestrial conditions can be similar to, or even greater than, that of NTN. In some cases, switching to an NTN link can reduce energy drain compared to continuously struggling with a weak and intermittent terrestrial signal.

Similarly, in scenarios with no terrestrial coverage, devices running a terrestrial-only stack can waste substantial power repeatedly searching for a network that does not exist. On the other hand, an NTN-enabled device can establish predictable satellite connectivity, ensure communication, and avoid the energy costs of terrestrial scans.

Nordic’s Strategic Position in the NTN Ecosystem

Nordic views NTN as a practical enhancement to its cellular IoT portfolio. As networks such as 2G and 3G are sunsetting, NTN offers a dependable fallback, and in some cases, the only viable connectivity option for remote or underserved regions. 

Supporting both LEO and GEO constellations within a single design is a deliberate choice. Each constellation type offers distinct performance characteristics such as latency, throughput, and coverage patterns that make it better suited for different applications. Nordic enables both, giving developers flexibility to address diverse use cases.

In practice, M(V)NO’s decide which NTN networks they set up roaming agreements with. Depending on which terrestrial M(V)NO you use, you may only be able to roam to specific NTN networks. Many M(V)NOs establish roaming arrangements with multiple NTN providers, similar to how roaming is managed between terrestrial networks, giving you more options. For user equipment (UE) devices, the primary requirement is the capability to connect to whichever NTN networks the SIM’s roaming agreements allow. Nordic’s 3GPP standards-based implementation supports this model, ensuring that devices can transition between terrestrial and satellite networks seamlessly, without requiring changes to the underlying hardware.

Nordic’s existing developer ecosystem, comprising hardware platforms, software development kits, cloud integration tools, and established support channels, extends to NTN-enabled solutions. This continuity allows developers to work with the same tools and processes they already use for terrestrial IoT projects. Nordic combines a common hardware platform with a unified software and support framework, reducing the barriers to adopting NTN and enabling customers to design products that are both globally connected and adaptable.

Conclusion: Toward Truly Global IoT

The integration of NTN with terrestrial cellular IoT creates a path to resilient, truly global connectivity. Hybrid solutions can provide continuous coverage, maintain communication during infrastructure outages, and expand IoT deployment possibilities into previously unreachable regions.

Nordic Semiconductor’s nRF9151 module, with its NTN-capable LTE stack, offers developers a way to adopt this technology using familiar hardware and development tools. Nordic provides a platform that can adapt to changing coverage conditions and application requirements by enabling both GEO and LEO connectivity alongside terrestrial technologies like LTE-M. Integrating NTN into IoT designs today positions products for long-term relevance and operational flexibility.

To learn more about how Nordic Semiconductor enables hybrid NTN and cellular IoT with the nRF9151 module, visit their website or contact a Nordic representative for early development guidance. Learn more about Nordic Semiconductor at CES 2026.

References

1. Nordic Semiconductor. [Online] Available at: https://www.nordicsemi.com/ (Accessed on August 03, 2025)

2. nRF9151 [Online] Nordic Semiconductor. Available at: https://www.nordicsemi.com/Products/nRF9151 (Accessed on August 03, 2025)

3. Cellular IoT (LTE-M and NB-IoT) [Online] Nordic Semiconductor. Available at: https://www.nordicsemi.com/Products/Wireless/Low-power-cellular-IoT/What-is-NTN#infotabs (Accessed on August 03, 2025)