Fraunhofer IIS Demonstrates 5G-NTN in the Ka-band at 137 Mbit/s
Fraunhofer IIS has demonstrated a broadband 5G NTN connection via the geostationary satellite Heinrich Hertz. The Ka-band test achieved speeds of up to 137 Mbit/s and, for the first time, demonstrated a handover between two GEO satellite beams in the FR2 spectrum.
Broadband 5G connection via GEO satellite
In April 2026, the Fraunhofer Institute for Integrated Circuits IIS successfully tested an end-to-end 5G NTN connection via the geostationary communications satellite Heinrich Hertz. The transmission took place in the Ka-band, specifically in the 5G frequency band n512, and was based on 3GPP Release 18.
In the experiment, the researchers used various channel bandwidths between 50 and 100 MHz. Data rates of up to 137 Mbit/s were achieved. The transmission and reception equipment adapted for this purpose was located at the Fraunhofer IIS headquarters in Erlangen.
The tests were conducted as part of the Heinrich Hertz Mission. This mission is led by the German Space Agency at the German Aerospace Center and funded by the Federal Ministry of Research, Technology, and Space.
Ka-band as the basis for high-capacity NTN connections
Geostationary satellites can cover large areas on the ground and transmit high volumes of data. They are particularly suitable for applications where high capacity is more important than very low latency. These include, for example, streaming services or the distribution of software updates.
For future non-terrestrial networks, GEO satellites thus represent a potential high-capacity backbone. They can complement terrestrial and near-Earth network components, particularly when network coverage over large areas, backup connectivity, or additional transmission capacity is required.
For system integrators and network architects, it is particularly relevant that 5G-NTN cannot be viewed merely as a supplement for remote regions. The technology could also become part of hybrid 3D network architectures in the future, where terrestrial mobile networks, satellite connections, and other non-terrestrial components work together.
Specialized Equipment for High Channel Bandwidths
The Ka-band is already established in traditional satellite communications. The transmission of 5G signals at high gigahertz frequencies, however, has not yet been extensively tested technically. According to Fraunhofer IIS, gateways with integrated 5G base stations and compatible NTN receiver terminals are not yet available on the market.
For the test, Fraunhofer IIS therefore developed specially adapted transmission and reception equipment. This enabled broadband 5G transmissions with up to 100 MHz of channel bandwidth.
Rainer Wansch, Head of the RF and SatCom Systems Department at Fraunhofer IIS, views the test as a foundation for integrating satellites into future 3D networks. The goal is to implement broadband 5G connections via satellite in a way that allows them to interoperate with existing 5G infrastructure.
Inter-beam handover for mobile applications
In addition to the data rate, the handover between two satellite beams was also tested. Modern GEO satellites use multiple individual transmission beams to cover different coverage areas on the ground. When a user switches from one beam to another, the connection must be handed over stably.
This is particularly important for mobile applications, such as internet on airplanes or aboard ships. In these scenarios, a seamless handover between beams can determine whether passengers, crew, or connected systems remain online continuously.
Fraunhofer IIS demonstrated such a handover between the north and south beams of the Heinrich Hertz satellite. According to the institute, this marks the first successful demonstration of an inter-beam handover in the FR2 spectrum.
Software-defined 5G components in the test setup
For the experiment, the researchers implemented the handover capability in both the 5G base station used—the gNodeB—and the 5G terminal, the user equipment. Both components were fully software-defined.
OpenAirInterface, an open-source implementation of the 5G protocol stack, served as the technical foundation. Fraunhofer IIS extended this implementation to support high channel bandwidths and inter-beam handover.
This aspect is relevant for solution partners and technology providers because software-defined test environments enable flexible testing of new NTN functions. At the same time, the test demonstrates which additional adjustments are necessary to make 5G-NTN in the Ka-band practically usable.
Significance for 5G-NTN and industrial connectivity
The demonstration shows that broadband 5G-NTN connections via geostationary satellites are technically feasible. In particular, the combination of high channel bandwidths, Ka-band transmission, and handover functionality addresses key requirements for future satellite-mobile integration.
For end users in industries with mobile or widely dispersed assets, this could open up new options for continuous connectivity in the future. These include transportation, shipping, aviation, critical infrastructure, and industrial sites outside of dense terrestrial network coverage.
For system integrators, the relevance lies primarily in the architectural question: 5G-NTN is evolving from a supplementary satellite connection into a building block of standardized 5G networks. The results from Fraunhofer IIS provide concrete technical validation of this in the Ka-band.
More details on the 5G-NTN test in the Ka-band can be found on the Fraunhofer IIS website: https://www.iis.fraunhofer.de/en/pr/2026/press-release-high-bandwidth-GEO-satellites.html