June 27, 2025
LPWA, AirLink, LoRa, NB-IoT, Satellite / NTN
In 2024, mobile network coverage of 3G or higher was available to 96% of the global population, with gaps in the least developed and landlocked developing countries. Even with high population coverage, there are still many geographic cellular coverage gaps since networks are concentrated in urban and suburban centers. Many rural and remote locations, even in developed nations, have spotty or limited cellular or LPWAN service.
Enter non-terrestrial networks, or NTNs. NTNs fill cellular coverage gaps in remote areas by extending terrestrial networks. They aren’t subject to disruptions from natural disasters or sabotage, so they can serve an important role in emergency communications. NTNs are a great fit for outdoor use cases, such as tracking assets that are moving across geographies or networks such as logistics or livestock tracking, as well as connecting to fixed assets in remote areas like electrical infrastructure or oil and gas pipelines.
Types of Satellite NTNs: LEO/MEO/GEO
Satellites can operate in one of three positions. The first is the geostationary equatorial orbit (GEO), which is a fixed position relative to Earth - precisely 35,786 kilometers above the surface. Satellites can also operate in the medium Earth orbit (MEO), which represents an altitude range between 2,000 and 35,786 kilometers. The low Earth orbit or LEO is anything between 160 and 2,000 kilometers above Earth.
For more information on the differences between LEO and GEO, download our eBook The Convergence: Satellite and 5G for Mission-Critical Success.
Satellites present the largest opportunity to extend cellular coverage, but there are many types of satellite communication technologies. Commercial network operators have chosen different technical approaches, so how can your organization know which partnerships to pursue?
Technological Approaches to Satellite IoT
Operators with LEO and GEO satellite networks are taking one of two technological approaches, using either proprietary technology or direct-to-cell technology.
- Proprietary technology includes infrastructure that is not commercially available to other operators. Whether that infrastructure is specialized satellites that connect directly to proprietary devices, terrestrial workstations, telematics devices, or a software platform, proprietary solutions offer an end-to-end experience. One example of a proprietary operator is ORBCOMM, which owns more than 30 LEO satellites and corresponding ground infrastructure.
- Nb-IoT over NTN: The 3GPP organization develops specifications for all cellular technologies, including narrowband IoT (NB-IoT). NB-IoT has had global adoption and the last few 3GPP updates extended the standard to non-terrestrial networks. 3GPP Rel-19 provides a major step forward in the integration of NTNs with 5G by its inclusion of a complete gNodeB (gNB) on a satellite, which minimizes the need for a ground network. Commercial operator Skylo uses legacy Viasat GEO satellites and existing devices for its NB-IoT NTN.
- NTN LoRaWAN® combines a mature LoRa® ecosystem with GEO and LEO satellites which act as LoRaWAN gateways in the sky. The use cases are sensor oriented such as gathering real-time temperature and moisture data, monitoring electrical grid infrastructure for vibrations or water meters readings. At least three companies have commercialized these LoRaWAN NTNs, including EchoStar Mobile with GEO satellites, Lacuna space and Plan-S with LEO constellations
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Direct-to-cell technology uses LEO satellite systems that can communicate directly with commercially available cellular devices, bypassing cell towers on land. Cellular is then possible in rural, remote, or disaster areas. Depending on the operator, voice, text, and data communications are enabled. Starlink is one example, launching direct-to-cell services with over 320 specialized satellites, partnering with mobile carriers to use their existing licensed spectrum.
Which solution is right for my company?
Each of these technologies offers advantages and disadvantages to be considered relative to your specific needs and use cases. Considerations include:
- Coverage
- Latency
- Download speeds
- Switching (from non-terrestrial to terrestrial networks)
- Application awareness
- Readiness/availability
Proprietary solutions are known for their spectral efficiency and ease of implementation. However, their networks require their own specialized devices, which can be expensive. These networks also don’t offer seamless roaming to terrestrial networks.
Direct-to-cell use legacy LTE devices, which lowers total implementation costs. Capacity and performance are strong, with latency around 30 milliseconds. Direct-to-cell offers seamless roaming to terrestrial networks which is necessary for many applications. But implementing LEO satellite networks is complicated, which drives up costs for the end user. And direct-to-cell technology is in the early stages, with many uncertainties relative to performance and future proofing.
NB-IoT over non-terrestrial networks can operate with GEO or LEO satellites, so they can take advantage of existing infrastructure. They offer seamless roaming, and using simpler satellites means a lower cost of service. NB-IoT NTN is perceived as having better coverage than other solutions and fits well with a non-contiguous coverage deployment. Six times less spectrum is needed compared to LTE-M. NB-IoT NTN doesn’t support connected mode handoffs, leading to easier implementation. But it offers minimal capacity and low performance (latency around 280 milliseconds).
The great thing about NTN LoRaWAN is that it can complement NB-IoT in both the terrestrial and non-terrestrial space. The ecosystem is large and mature, devices are very low power and low cost, and it supports roaming to terrestrial LoRaWAN networks. There is much more latency than NB-IoT NTN though, so message size is limited which is why it’s primarily used for sensor use cases. It doesn’t support IP data.
Semtech and Non-Terrestrial Networks
All AirLink® routers can support satellite communications, including proprietary solutions. A satellite receiver connects through an Ethernet LAN port, which creates an additional WAN link. The router can then automatically find the best link, or you can set up satellite fallback based on chosen criteria. Learn More.
The market for standardized NTNs, like 3GPP NB-IoT and LoRaWAN is growing faster than for proprietary satellite offerings. In addition to Skylo, at least three additional operators plan to have 3GPP commercial service within the next year, while LoRaWAN satellite operators keep expanding their infrastructure adding more satellites
Companies who want to be ready for this proliferation of non-terrestrial network operators can proactively verify that their devices will work seamlessly with these 3GPP networks, or adapt their LoRaWAN design for satellite. For example, Skylo currently certifies devices, modules, and chipsets to operate on its network. These devices must be adaptable to the latest 3GPP NTN standards as well as meet Skylo’s Standard Plus requirements, which are additional technical specifications designed to improve functionality and interoperability.
Semtech offers two modules that support 3GPP non-terrestrial networks and are Skylo certified. The Semtech HL78 series LPWA modules already offer best-in-class power efficiency and broad coverage to support low power deployments. Now the HL7810 and HL7812 are certified to work seamlessly with the Skylo network. Learn More.
On the other hand, Semtech 3rd generation (LR1110/LR1120/LR1121) LoRa chips offer the ability to set up a LoRaWAN NTN connectivity through reference designs or modules provided by the various LoRaWAN NTN operators
Semtech customers are already using NB-IoT NTN or LoRaWAN NTN to enable a variety of use cases like asset tracking, oil and gas pipeline monitoring, and livestock tracking. These current customer applications are ideal to use non-terrestrial networks because they are outdoors, often in remote areas, and – in the case of livestock tracking – typically have an unimpeded view of the sky.
See how Net Feasa leverages LPWA cellular, satellite and LoRa technologies for global container tracking.
The Future of IoT with Non-Terrestrial Networks
Regardless of the IoT use case, coverage is always an issue. Companies must carefully plan for fallback depending on where in the world the application operates. Now there is the potential to have a fallback technology that will likely be available everywhere. This gives the benefits and scale of standard technologies with the ability to connect over satellite anywhere in the world.
The Semtech HL7810 and HL7812 didn’t need a hardware change to meet Skylo certification requirements; instead, a firmware update supplied all necessary technical changes. The modules that you’re already using for your LTE coverage now offer this additional capability with no additional hardware costs.
With Semtech 3rd generation LoRa chips the low power benefit of LoRaWAN becomes now available for direct to satellite connectivity, with the opportunity to keep full interoperability with terrestrial LoRaWAN networks
Semtech continues to drive innovation and enables seamless global connectivity to meet the digital needs of its customers.
1 - ITU (International Telecommunication Union) - "Facts and Figures 2024 - Mobile network coverage"
Semtech®, the Semtech logo, AirLink®, AirVantage®, Lora®, and LoRaWAN® are registered trademarks or service marks of Semtech Corporation or its affiliates. Other product or service names mentioned herein may be the trademarks of their respective owners.
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