The classic economics of supply and demand have stunted the roll-out of internet infrastructure around the world, leaving 2.9 billion people still unconnected today. Addressing this challenge has been the remit of public policy makers, corporations, and researchers for decades.
On earth connectivity is defined by the boundaries of physical networks made of towers or cables. This means that where there is not enough demand because of sparse populations in remote areas, the business case for building the infrastructure isn’t there. Satellites are not constrained by these same terrestrial realities, having the capacity to deliver an equality of service across the world from their orbital locations above the earth. This has made the idea of connecting end user devices like laptops and phones to the internet via satellite compelling. But the technical challenges involved in achieving this utopian vision of truly ubiquitous internet made it just that, a hope for one day in the future.
That day is now closer thanks to the University of Luxembourg’s Interdisciplinary Centre for Security, Reliability and Trust (SnT) exploring direct 5G connections via satellite in the project 5G-GOA. The waveform of 5G can travel the distance to satellites, unlike 3G or 4G, making it feasible to consider connecting user equipment (UE) like phones and laptops to a satellite. With the roll-out of terrestrial 5G now the question is how to harness the opportunity of 5G to satellite and make it technically possible to use the frequency in this way.
The 5G-GOA project has done this, making it the latest success of SnT’s world-leading research group in satellite communications, the Signal Processing and Communications (SIGCOM) group. For 10 days in October the 5G-GOA team were given capacity on a commercial satellite to do real-world testing of the 5G to satellite protocol that they have developed.
The demo happened live in Stresa, Italy, at the 27th Ka and Broadband Communications Conference (Ka) and the 39th International Communications Satellite Systems Conference (ICSSC) and its Colloquium, the two most influential technical conferences on satellite systems. During the demo the team validated functionalities like YouTube streaming, voice calls, and file transfer via a 5G connection to a satellite. This makes it the first ever proof-of-concept of this connection. For the project they are using a software defined radio (SDR) to receive and transmit a 5G signal directly with a satellite in a geostationary orbit (GEO).
“We connected a commercially available software defined radio which is roughly the size of a shoe box, so to replicate this connection in a phone there needs to be innovation on the hardware side,” said Dr. Sumit Kumar, member of SIGCOM and of its 5G-GOA research team. “We are still years away from seeing a user device like an off-the-self phone or tablet establish a broadband internet connection directly via satellite, but this proof of concept demonstrates that it is possible, paving the way for further research and technology development.”
The 5G-GOA project is funded by the Luxembourg Space Agency (LSA) and the European Space Agency (ESA) through its “Advanced Research in Telecommunications Systems” (ARTES) programme. The objective of the 5G-GOA project is to show that 5G connectivity is as possible via satellites as it is via terrestrial base stations on Earth. The project consortium consists of partners from the SnT (University of Luxembourg), Fraunhofer IIS, the Bundeswehr University Munich, and EURESCOM. The project is unique because it is using the same 5G signal that is being used for terrestrial networks, meaning that the research can set to stage for a future where one mobile phone can connect to the internet via terrestrial networks or satellite, depending on the availability of service.
The project builds upon the standards that have been set for 5G communications in the 3GPP. The latest release of 3GPP, number 17, included non-terrestrial networks, making it the first-time satellite communication standards have been addressed in a 3GPP release. 5G-GOA is the first project to apply these standards and use them to demonstrate a proof-of-concept.
“We learned a lot during the 10 days of connection we had and will be running the experiment again soon for a more mature version of the demonstration,” said Dr. Kumar. “We are very satisfied with the outcome of the project already. 5G is a quantum jump in terms of technology, making the dream of a non-terrestrial network feasible.”
A non-terrestrial network will not be hampered by the economics of supply and demand, as demand is limitless from the vantage point of a satellite network. That means that it will be possible to deliver the life-changing power of the internet to anyone who can afford a device. In a world with 2.9 billion people still unconnected, the potential impact of this technology is boundless.
 International Telecommunication Union (ITU), Global Connectivity Report 2022, https://www.itu.int/itu-d/reports/statistics/global-connectivity-report-2022/