Image: Enno Kapitza for DLR

Future Communications Infrastructure (FCI) for civil aviation

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.

One core working area of the team is the design and validation of the future international aeronautical communications system LDACS (L-band Digital Aeronautical Communications System). LDACS has been developed in main parts at DLR and is foreseen for standardization within the next years. Being a high-performant, high-rate data link, LDACS enables modern ATM applications as currently being developed within the international ATM projects SESAR (Europe) and NextGen (US). The communications systems LDACS has the potential to be extended towards navigation and surveillance. The further development of LDACS towards an integrated CNS (Communications, Navigation, Surveillance) solution is another core working area of the team.

Besides their work on ground-based communications with LDACS, the team also designs and evaluates concepts for direct communications between aircraft, i.e. Air-to-Air (A2A) communications. Together with the Satellite Networks Department, who is covering satellite-based communications to the aircraft, the networking of the different data link technologies into a heterogeneous, IPv6-based aeronautical internet is advanced. Linking the aircraft via different communications media to the infrastructure on ground enables new multilink and redundancy approaches.

The Aeronautical Communications Group is actively working in different committees and boards, e.g. the Future Communications Infrastructure Task Force (FCI-TF) of Eurocontrol, the Communications Panel and the Navigation Systems Panel of ICAO. In the latter two, the team acts as advisor to DFS.

Research Topics of the Team

• A/G and A2A communications
  • OFDM-based system design
  • Optimization of OFDM receiver techniques
  • Interference mitigation
  • Coding
  • Synchronization
  • Coexistence with other CNS systems
  • Robust and efficient multiple-access, especially in self-organizing networks
  • Aircraft-based surveillance
• LDACS extension towards navigation
  • Use of LDACS signals for ranging
  • LDACS as ranging sensor for APNT (Alternative Positioning, Navigation, and Timing)
  • Increased ranging accuracy
• LDACS extension towards surveillance
  • Use of LDACS signals as „radar signals“ – feasibility study
  • Non-cooperative radar concept
  • MIMO (Multiple-Input Multiple-Output) radar
• Channel modelling
  • A2A channel model
  • A/G channel model (especially also for APNT)
• DLR-Vision „Networking the Sky“
  • Heterogeneous, IPv6-based aeronautical internet
  • Mobility, Handover, Routing
  • Multilink concept
• Robust and secure communications at physical layer (see project ARIEL)
• Integration of UAS into civil airspace through CNS (see project UFO)