Book excerpt: Aeronautical communications is seen as a major bottleneck stressing capacity limits in air transportation. Ongoing research projects are developing the fundamental methods, concepts and technologies for future aeronautical communications that are required to enable higher capacities in air transportation. The demand for making air traveling more pleasant, secure and productive for passengers is one of the winning factors for airlines and aircraft industry. In an aeronautical scenario global coverage is essential for providing continuous service. Therefore satellite communication becomes indispensable, and together with the ever increasing data rate requirements of applications, aeronautical satellite communication meets an expansive market. The Aeronautical Communications Group designs and evaluates digital wireless communications systems for civil aviation. These systems are designated for the following application areas: Air-Traffic Control (ATC), Air-Traffic Management (ATM), Airline Operational Control (AOC) as well as command and control of Unmanned Aerial Systems (UAS) and their integration into civil airspace.Future Aeronautical Communications, a comprehensive guide to current systems, networks and topologies, covers application requirements for communication and related radio-navigation and surveillance functions in aeronautical systems. The book gives the readers the opportunity to deepen and broaden their knowledge of this field. Today's and tomorrow's problems / methods in the arena of aeronautical communications are treated: contemporary trends are acknowledged; IPv6 aeronautical network aspects are covered; challenges for the satellite component are demonstrated.