@phdthesis{Freimann2022,
  author    = {Freimann, Andreas},
  title     = {Efficient Communication in Networks of Small Low Earth Orbit Satellites and Ground Stations},
  isbn      = {978-3-945459-41-6},
  doi       = {10.25972/OPUS-28052},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-280521},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2022},
  abstract  = {With the miniaturization of satellites a fundamental change took place in the space industry. Instead of single big monolithic satellites nowadays more and more systems are envisaged consisting of a number of small satellites to form cooperating systems in space. The lower costs for development and launch as well as the spatial distribution of these systems enable the implementation of new scientific missions and commercial services. With this paradigm shift new challenges constantly emerge for satellite developers, particularly in the area of wireless communication systems and network protocols. Satellites in low Earth orbits and ground stations form dynamic space-terrestrial networks. The characteristics of these networks differ fundamentally from those of other networks. The resulting challenges with regard to communication system design, system analysis, packet forwarding, routing and medium access control as well as challenges concerning the reliability and efficiency of wireless communication links are addressed in this thesis. The physical modeling of space-terrestrial networks is addressed by analyzing existing satellite systems and communication devices, by evaluating measurements and by implementing a simulator for space-terrestrial networks. The resulting system and channel models were used as a basis for the prediction of the dynamic network topologies, link properties and channel interference. These predictions allowed for the implementation of efficient routing and medium access control schemes for space-terrestrial networks. Further, the implementation and utilization of software-defined ground stations is addressed, and a data upload scheme for the operation of small satellite formations is presented.},
  subject      = {Satellitenfunk},
  language  = {en}
}