Satellite swarm to provide 5G mobile communications coverage
How can we make the latest generation of mobile communications ("5G") accessible across the globe? A Bremen project team from industry and science has now joined forces to bring a cross-linked swarm of small satellites into space to supplement the network on the ground. According to Benny Rievers from the Center of Applied Space Technology and Microgravity at the University of Bremen, the advantages are obvious: "With the help of approximately 1,000 small satellites, we achieve complete coverage of the earth's surface – except for the poles - and with the swarm system we are significantly less sensitive to failures of individual satellites.”
Compared to the 4th generation of mobile communications (LTE) the new 5th generation should achieve a data rate of 10 to 20 gigabits per second and ideally enable new applications. This applies, for example, for autonomously operated machines in agriculture or for the precise coordination of emergency medical services, but logistics companies and shipping also need the "Internet of Everything and Everywhere" (IoEE). Also autonomous driving can only be used in an optimal way where the network infrastructure is designed for 5G.
Geographical gaps in the network
The problem is that by the end of 2022 at least 98 percent of households in Germany will be able to access 5G, but only 80 percent of the area will be covered. This will make autonomous vehicle operation over long distances difficult, and many rural regions will continue to be left behind.
A large-scale constellation in a near-earth orbit, as envisaged by the Bremen team, would provide a second communication level at an altitude of around 1,000 kilometers that would guarantee complete coverage of the earth and immediately compensate any failures of individual satellites.
Before the actual satellite mission is planned, however, the participants will first develop a software platform for the simulation and design of a 5G satellite network. The platform should be able to answer questions such as: Which maximum data rate can be guaranteed in a region like Northern Germany? How many satellites are needed? What is the maximum distance between them? And how are they most efficiently connected – among each other but also with the ground stations?
In addition, such a network of small satellites could be used for other purposes, like earth observation and climate research. In this case, the small satellites only need to be supplemented by an additional observation module. The project of the Bremen actors will lay the foundation for such modular systems, which will stand out from previous systems due to their higher flexibility and efficiency.
Experts joined in Bremen
All necessary competences for the realization of such a network are available at the space city Bremen. The working group of Professor Armin Dekorsy from the Department of Communications Engineering and Signal Processing (ANT) has been involved in the development of the 5G mobile communication standard from the very the beginning and has the necessary expertise in telecommunications engineering. The working group Optimization and Optimal Control of the Centre for Technomathematics at the University of Bremen (Professor Christof Büskens) contributes know-how for the optimization of complex systems, while ZARM (Professor Claus Lämmerzahl) focuses on mission planning. For an analysis of the potential performance of satellite networks, high-precision computer models are developed at ZARM to calculate the position and location of the satellite systems. These models are used to generate virtual data, so-called mock data sets, which can be used to evaluate which mission concepts and satellite configurations provide the best possible performance. The results will then be evaluated by the Centre for Technomathematics to optimize the respective scenarios. ZARM Technik AG addresses the pointing and attitude changes of the satellites in space using special magnetic torquers for the smallest satellites. These have to meet particularly high expectations, as they not only ensure the required attitude for communication with Earth, but also within the satellite network. OHB System AG and DSI Aerospace Technologie GmbH have decades of experience in the design of satellites and communication modules. OHB is mainly responsible for the conception of the design for the satellite bus within the scope of the project, while DSI defines the communication concepts and hardware requirements.
The project 5GSatOpt („Design, Evaluation and Optimization of 5G Satellite Constellations for the Internet of Everything and Everywhere”) is funded by the State of Bremen with financial resources from the EU EFRE program.
contact for scientific questions:
Dr.-Ing. Benny Rievers
0421 218-57930
benny.rievers(at)zarm.uni-bremen.de
contact for media inquiries:
Birgit Kinkeldey
0421 218-57755
birgit.kinkeldey(at)zarm.uni-bremen.de
