5G Satellite Integration

5G is giving the convergence of terrestrial and satellite-based networks a major boost. For the first time, the concept of non-terrestrial networks (NTN) is systematically taking satellite integration into account in the standardization of a new mobile communications standard. This is good for both sides: not only does it mean terrestrial cellular networks can count on satellite support to overcome any range limitations, it also gives the satellite industry the opportunity to expand its range of services far beyond the provision of satellite TV and Internet.

The traditional method, backhaul, involves using satellites to connect cellular base stations on the ground. Satellite backhaul is what connects base stations in remote areas to the cellular network, if necessary without any further infrastructure. By serving as connection points between cellular base stations on the ground, satellites establish a global communications network that can play a major part in the rapid rollout of 5G connectivity worldwide. This type of connectivity is already well established, but always requires that both the satellites and users’ devices have a stable connection to a cellular base station.

New ways to connect – 5G direct access via satellite

At Fraunhofer IIS, we go one step further and focus on developing technologies for direct communication between satellites and users’ devices as a way to combine terrestrial and satellite-based communication systems.

These newer concepts for integrating satellites into 5G terrestrial infrastructure are based on direct connectivity between satellites and 5G-enabled user equipment (UE). These devices then have satellite-based access to the 5G network at all times – even when there is no base station nearby. In the future, this will mean that smartphones or vehicles can establish a connection either via a cellular base station or directly via satellite, depending on the reception situation. Network architectures are also possible in which the satellite itself, either fully or partially, serves as the base station (gNB).

Why 5G direct satellite access?

For certain applications, a direct connection between satellites and receivers offers particular benefits:


Guarantees reception anywhere for fixed VSAT modems or mobile users and IoT devices – even in the world’s most remote regions.

Seamless reception for mobile applications

Offers reliable transmission of updates and warnings to vehicles or continuous transmission of IoT sensor data.

Efficient broadcast

Relieves terrestrial infrastructure (data offloading) by transmitting media content and software updates via satellite to many mobile devices simultaneously.

Icon LEO satellite constellation
© Fraunhofer IIS


Especially in combination with various satellite operators’ recently launched or planned constellations, comprising a large number of smaller satellites in low earth orbit (LEO), the integration of satellites into the 5G network offers great opportunities for reliable and global cellular coverage without any gaps.

How we are driving 5G satellite integration

Technology development and consulting



We develop and test the latest approaches to integrating terrestrial and satellite-based communication. On this basis, we would be happy to advise you on all questions relating to satellite communications and 5G.

Our offer includes consulting services related to 5G standardization as well as feasibility studies and the development of system-specific integration concepts.

and analysis



Learn how your satellite system can benefit from 5G NR (New Radio): To determine the performance of 5G NR direct access via satellite, we offer link- and system-level simulations for established and new systems.

We have simulation tools available that allow a quick and detailed analysis of all important performance parameters.

and demonstration



To validate the performance of 5G NR via satellite in actual transmission, we use the OpenAirInterface (OAI) prototyping platform.

This enables us to implement new features from the ongoing standardization process at an early stage and to try them out in live tests. Our laboratories also have the necessary equipment to realistically reproduce various channel characteristics in satellite transmission.


Current research projects

  • 5G-GOA – 5G enabled ground segment technologies and over the air demonstrator via GEO satellite

    The objective of the 5G-GOA project is the development and implementation of necessary 5G New Radio modifications according to the 3GPP standardization of 5G NTN in order to enable direct radio access of terrestrial communication networks via GEO satellite. The project is funded by the European Space Agency (ESA).

    Fraunhofer IIS provides new software developments for the 5G-enabled prototypes of the base station (gNB) and the mobile end devices (UE), both based on OpenAirInterface.

  • 5G-IS – 5G system infrastructure study

    The study 5G-IS, which is funded by the European Space Agency ESA (Directorate of Telecommunications and Integrated Applications TIA) addresses the huge potential of satellite-based 5G and beyond services for global connectivity and their infrastructural requirements.

    Fraunhofer IIS brings its expertise in 5G satellite integration to this project.

  • In the 5G-LEO project, funded by the European Space Agency ESA, Fraunhofer IIS works with partners in order to extend the OpenAirInterface (OAI) open source code to support satellite systems in non-geostationary orbits. This extension will implement a full 5G protocol stack (Release 17) for both the user equipment (UE) and the base station (gNB). The main outcome of this activity will be a publicly available updated version of the OAI software library with new features to simulate and to test 5G communication links over satellites in low earth orbit (LEO).

  • 5G METEORS – ESA MakerSpace for 5G and satellite communication

    5G METEORS, funded by the European Space Agency (ESA), addresses a broad range of challenges in the 5G and satellite convergence and integration domain, specifically for the direct usage of 5G New Radio over satellites. The program funds several smaller activities comprising the implementation and demonstration of 5G direct access over satellites.

    Fraunhofer IIS provides technical support for the coordination of the 5G METEORS program and contributes with 5G NTN technology demonstrations.

  • 6G SENTINEL is a Fraunhofer lighthouse project. Through its lighthouse projects, the Fraunhofer-Gesellschaft sets strategic priorities to develop specific solutions that will benefit German industry. In the 6G SENTINEL project, five participating Fraunhofer Institutes are developing key technologies for the impending 6G mobile communications standard.

    One focus of Fraunhofer IIS is on system level simulations for future hybrid networks in order to comprehensively test the integration of satellites into 6G mobile networks.

  • 6G-SKY – 6G for Connected Sky

    In the 6G-SKY project, solutions for the next generation of mobile communications are being developed to ensure reliable and robust networking on the ground and in the air. 6G-SKY is funded by the German Federal Ministry for Economic Affairs and Climate Action in the framework of the European research initiative CELTIC-NEXT.

    Fraunhofer IIS is leads the German project consortium, advances 6G system level simulations and participates in technology demonstrations of 6G links via satellite and terrestrial 6G links.

More information



Satellite connectivity


5G and beyond

Technologies for a connected world


Consulting for 5G technologies

Benefit from our 5G skill-set