DLR - Institute of Communications and Navigation

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Communications Systems

The focus of the Department Communications Systems is on (1) communications for aircraft, drones, trains, road vehicles, and ships, (2) navigation in difficult environments, and (3) swarm exploration. Cross-cutting topics of the department are estimation theory, transmission methods, and channel modeling. Most of our topics cover system aspects. We develop prototypes in all areas and conduct numerous measurement campaigns. Our research work is very well suited for doctoral studies. About half of our colleagues are currently working on their PhDs.
In the area of communications, we are pursuing the development and standardization of LDACS, the future global communications standard for air traffic management, together with numerous partners from Germany and abroad. In the long term, LDACS will replace the analog air radio currently used worldwide. We are also developing data links for communication with unmanned, remote-controlled aircraft and with autonomously flying drones. To enable innovative rail concepts (next generation train), we are looking at new communication methods for railroads and focusing on communication between trains (train-to-train). For shipping, we are also involved in the development, demonstration and standardization of new transmission methods. The communication requirements and framework conditions for the above-mentioned modes of transport differ greatly from one another. For much of our work, we require detailed knowledge of wave propagation. We therefore perform channel measurements in all relevant environments (aircraft-to-ground, satellite-to-aircraft, drone-to-drone, ship-to-ship, ship-to-coast, train-to-train, vehicle-to-vehicle), model channel characteristics, and contribute to standardization at ITU-R.
Using multisensor navigation methods, we enable accurate indoor navigation for pedestrians and aim to use a variety of sensors from the smartphone and "wearables" to provide accurate position at all times inside buildings and also in the diverse use of urban transportation. In addition to the interior of buildings, tunnels are also inaccessible to satellite navigation signals. Thus, we are developing new methods to determine the position of trains in tunnels, using innovative techniques to exploit the earth's magnetic field, which is highly disturbed along the rail (RailSLAM). We are also designing and demonstrating new navigation procedures for swarms of rovers for missions on Moon and Mars.
We are designing autonomous and decentralized exploration procedures for swarms of rovers and flying platforms to explore foreign planets and to support disaster control. We deploy swarms that can explore much faster than a single rover, are robust to failures, and can observe physical phenomena such as gas leakage simultaneously from multiple locations.

Aeronautical Communications Group

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, IP-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.

Vehicular Applications Group

The research interests of the Vehicular Applications Group lie in the area of novel systems that combine robust navigation, ad-hoc communications and information processing. We are addressing applications such as safety-of-life relevant cooperative assistance systems for vehicles and collision avoidance systems for vehicles and trains, dynamic coupling of trains, ubiquitous and context aware pedestrian navigation, and activity estimation of pedestrians. Our work is conducted at experimental, simulative and theoretical levels. Much of our activity in the areas of navigation is at the signal processing level with the goal of assessing and improving the performance of future navigation systems in challenging environmental scenarios such as heavy shadowing and multipath or under interference from other signal sources. Many of the problems we address can be formulated as estimation or decision problems and require a good understanding of underlying models, such as utilities, process and sensor models. We make a strong effort to validate our approaches in real world experiments and early prototypes.

Mobile Radio Transmission Group

The Mobile Radio Transmission Group covers terrestrial mobile radio communication systems. Research work focuses on the physical as well as the MAC layer. A further topic of the Group is the integration of Communication and Navigation, i.e., positioning using terrestrial mobile radio systems and exploitation of position information for communications.

Swarm Exploration Group

The main focus of the group is in the research and development of novel data processing algorithms for autonomous exploration of unknown or complex environments with mobile robotic platforms, e.g., quadrocopters or rovers. The algorithms address aspects of data processing that include decentralized methods for data acquisition and collaborative decision making, as well as advanced computational tools for in-network data analysis. Our vision is that intelligent swarm-based robotic systems will become primary tools for autonomous exploration of extraterrestrial environments, especially in cases when a direct control from Earth is compromised or delayed. Moreover, such intelligent systems might also become indispensable for situation awareness in emergencies or disaster control scenarios, when the access to infrastructure is limited or becomes unavailable.

Kontakt

Prof. Dr. Uwe-Carsten Fiebig
German Aerospace Center
Institute of Communications and Navigation, Communications Systems
Tel.: +49 8153 28-2835
Fax: +49 8153 28 2676