Thomas Gräupl

L-DACS 1 data link layer design and performance

The VHF COM band currently used for air-ground communications is becoming congested, and the future Air Traffic Management concepts will require much greater use of data communications than today. The wireless communication system discussed in this paper, L-DACS1, is considered a candidate system for this purpose. It has been derived from B-AMC, TIA-902 (P34), and WiMAX (IEEE 802.16e). The presented work, which was performed in a EUROCONTROL funded study, aimed at developing an initial system specification for L-DACS1. This system specification shall enable prototyping activities that in turn shall clarify system compatibility issues that could not be covered analytically or via modeling.

Newsky - building a simulation environment for an integrated aeronautical network architecture

The expected evolution of aircraft traffic in the next decades and the foreseen lack of communication resources in the European airspace produce an increased need for efficient data communications. Up to now the general trend has been the implementation of new communication links and the optimization of existing resources. However, the main goal of NEWSKY is to integrate different communication technologies into a global IP based aeronautical inter-network The NEWSKY approach tries to achieve improved communication capabilities through a network centric service oriented architecture. In order to evaluate this future aeronautical inter-network it is imperative to define new simulation environments. The primary intent of our work is to develop a simulation environment which is capable of evaluating algorithms designed for a heterogeneous mobile network environment, laying the main focus on the evaluation of mobility and connectivity management concepts. The secondary objective of this work is to integrate the effects of self separation algorithms, medium term conflict detection and resolution, and collision avoidance systems into the concept of the simulation environment. This paper introduces a set of fundamental concepts to the simulation of integrated aeronautical communications architectures. NEWSKY is funded by the European Commission within the 6th framework program.

Applying SOA concepts to the simulation of aeronautical wireless communication

The aeronautical environment will change significantly in the near future creating an increased need for efficient data communication. Although the general trend of the expected transformation is predictable, the details are subject to highly dynamic changes. Consequently simulations within this environment have to be able to reflect alternating requirements. By the application of service oriented architecture concepts a simulation suite robust against changing requirements has been developed. It is the intention of our work to achieve this goal, while keeping the architectural complexity low and fostering the incorporation of existing simulation tools. Additionally this approach allows the decomposition of complex simulation challenges into simpler sub-tasks; large scale simulations are easy to conduct through distributed processing. However, the gain of lower complexity is bought by a certain loss of computational performance. This paper presents an application of SOA principles to the simulation of aeronautical wireless communication. The simulation architecture used for the assessment of the B-AMC aeronautical communication technology is described in detail.

Final Assessment of the B-VHF Overlay Concept

B-VHF is a proposal for a future aeronautical communication system in the very high frequency (VHF) band based on an overlay concept, i.e. during the transition phase the B-VHF system shares the same frequency band with legacy VHF systems without interfering with them. In this paper, the feasibility of the overlay concept is evaluated by simulations of the physical and higher layers as well as by laboratory measurements with a demonstrator. Simulation results show that the B-VHF overlay system works in presence of interference from legacy VHF systems. The protocol is designed to allow using the available resources very efficiently and to provide voice and data services with the required quality of service. In addition, the impact of mutual interference between the B-VHF system and legacy VHF systems is evaluated in laboratory test with a simplified B-VHF demonstrator and commercial VHF radios.

TCP/IP over aeronautical communication systems — Effects on bandwidth consumption

The TCP protocol has been selected as the transport layer protocol of the ATN/IPS. However, there are multiple known deficiencies of the protocol when operating over ldquolong thin networksrdquo. In this paper we discuss several well-known TCP optimization techniques and their application to aeronautical data traffic. The performance of TCP is evaluated and analyzed in a simulated environment based on the COCR report.

Security consideration for IP based aeronautical networks

The internet protocol version 6 (IPv6) is the intended network protocol for the future ATN. In order to fully benefit from IP security capabilities it is important to understand the various mechanisms and the environment in which they will operate. This paper discusses the security conditions of aeronautical communication and analyzes the relevant issues in a generic way. More concrete considerations are given in the second part of the paper where threats (in terms of communication security) to the vision of NEWSKY are briefly discussed and IPv6 security service mechanisms are introduced.

Characterisation of the data link communication air traffic for the European airspace

The use of satellites for air traffic management purposes offers many benefits for the future aeronautical communications infrastructure. Satellites can provide seamless and nearly global coverage over land masses, oceans, and remote areas with a reduced terrestrial infrastructure. Research and Development for a new satellite based air-ground data link has been endorsed by the EU Transport Council. It is widely shared among stakeholders that use of this satellite link in dense continental airspace requires new performance standards, which calls for a new ATM-dedicated satellite communication standard and the supporting satellite capacity. This paper provides a characterization of the future data communication traffic profile and derives initial bandwidth estimation for a satellite system providing the service in the ECAC region.

B-VHF - Selected Simulation Results and Assessment

B-VHF is a proposal for a future aeronautical communication system in the VHF band based on an overlay concept, i.e. during the transition phase the B-VHF system shares the same frequency band with legacy VHF systems without interfering with them. In this paper, the overlay concept is evaluated by simulations of the physical and higher layers. Simulation results show that the B-VHF overlay system works in presence of interference from legacy VHF systems. The protocol is designed to allow using the available resources very efficiently and to provide voice and data services with the required quality of service

AeroMACS data traffic model

The future aeronautical airport communication system — AeroMACS — shall be based on WiMAX. A specifically drafted system profile suitable for airport communications shall be evaluated through simulations. In order to assess the performance properly an assumption on the data traffic load for airport surface communications was necessary. This paper presents the data traffic load model used as input for the AeroMACS communication profile definition.

Dimensioning requirements for the ANTARES ATM satellite data-link

▪ Iris is a dedicated ESA programme to develop a new satellite based air-ground communication system for air traffic management on the basis of the SESAR requirements. ▪ The analysis of the system dimensioning requirements is provides input to the system design. ▪ Air traffic: - In the investigated beam configurations (3 beams, 12 beams) the Iris satellite system has to support between 600 and 4500 A/C per beam. - In total the system need not support more than 6000 A/C. - Handover between beams are performed at rates < 1 HO/s.