Mavenir and mobile satellite operator Terrestar have completed the first Voice over NB-IoT (Narrowband Internet of Things) call in Non-Terrestrial Networks (NTN) mode.
The breakthrough — achieved in January 2025 — used a 3GPP-standardised NTN S-band spectrum, which strategically avoids interference prevalent in terrestrial networks.
Additionally, the system was designed to accommodate delays characteristic of geostationary Earth orbit (GEO) satellites, ensuring seamless and reliable connectivity despite the higher latency. This approach could enable GEO satellite operators to immediately monetise NTN services without excessive infrastructure upgrades.
The VoNB call was conducted using Sony’s Altair ALT1250 IoT module, Mavenir’s Open RAN (including Open vRAN and Open Beam radio), and Mavenir’s Converged Packet Core platform. Terrestar provided the S-band spectrum and operational expertise.
The successful demonstration serves as a proof of concept, showcasing how the integration of satellite and terrestrial technologies can deliver consistent communication services in underserved areas.
Transforming connectivity in challenging locations
The collaboration highlights a shared vision to bridge the connectivity gap in remote and challenging environments.
By leveraging 3GPP standards for NTNs, Mavenir and Terrestar aim to enable IoT solutions and reliable voice communications in areas beyond the reach of traditional cellular infrastructure.
Jacques Leduc, President of Terrestar Solutions, commented: “Terrestar Solutions embodies innovation and leadership as the first MSS player to offer a real-time voice service based on a fully compliant 3GPP non-terrestrial network.
“With our dedicated S-band spectrum and an open network architecture, we leverage the strength of the 3GPP ecosystem to drive a breakthrough that sets us apart.
”Our mission: to accelerate the ecosystem development and provide all, through their mobile service provider, with satellite mobile connectivity that ensures security, autonomy, and independence.”
Integrating satellite coverage with terrestrial capabilities increases reach to geographically-isolated areas, where laying traditional infrastructure is either impractical or cost-prohibitive. Simplifying implementation further, the partnership’s solution works seamlessly with widely available user devices, requiring only minimal adjustments such as software upgrades.
Sachin Karkala, SVP and GM of the RAN Business Unit at Mavenir, explained: “Satellite services provide the perfect addition to existing terrestrial networks, adding a layer of widespread coverage, and nowhere is this more important than underserved and remote regions.
“This development allows satellite operators to launch voice services immediately using available spectrum, existing GEO satellites and industry-standard user equipment with a simple software upgrade to deliver voice services country-wide.”
This collaboration exemplifies how partnerships between industry players can unlock previously untapped potential. The focus on interoperability and adherence to 3GPP standards ensures that developers, operators, and businesses can adopt these solutions with confidence and ease.
Advancing NB-IoT solutions like it’s NTN
The successful achievement lays the foundation for broader deployment of NB-IoT solutions in NTN mode—essential for supporting IoT devices and services in diverse sectors, including agriculture, logistics, energy, and disaster recovery. As the technology progresses, the inclusion of voice capabilities alongside data-driven IoT services broadens the scope of use cases for operators and organisations.
Beyond commercial implications, the partnership is likely to have profound societal impacts. By expanding connectivity to underserved and remote regions, it provides local communities with access to essential communication services — including voice calls — which remain critical in emergency situations.
The successful VoNB call builds on Mavenir’s capabilities in unifying networks and advancing global standards. Its Open vRAN technology, in particular, plays a role by enabling operators to reduce costs, increase flexibility, and scale more efficiently.
Combined with Terrestar’s experience in leveraging mobile-satellite spectrum, the collaboration serves as a model for harnessing innovation to solve real-world challenges.
As NTN technologies gain greater attention and adoption, this NB-IoT achievement marks an important step in turning the promise of ubiquitous connectivity into a reality.
See also: ETSI launches committee tackling IoT data sharing challenges
Want to learn about the IoT from industry leaders? Check out IoT Tech Expo taking place in Amsterdam, California, and London. The comprehensive event is co-located with other leading events including Cyber Security & Cloud Expo, AI & Big Data Expo, Intelligent Automation Conference, Edge Computing Expo, and Digital Transformation Week.
Explore other upcoming enterprise technology events and webinars powered by TechForge here.
