METHOD TO EMULATE THE L-BAND DIGITAL AERONAUTICAL COMMUNICATION SYSTEM FOR SESAR EVALUATION AND VERIFICATION

The VHF voice communication system currently used for air traffic control is experiencing increasing capacity problems. The “L-band Digital Aeronautical Communications System” is an upcoming technology providing an aeronautical datalink outside of the VHF band. The objective of this paper is to develop a method to emulate its communication performance. We developed a formal model of the system and implemented it on the basis of the dummynet network emulation tools. This implementation was deployed in a networking appliance and measured in a test-bed network. The results indicate that the emulator provides the performance predicted by simulations and is suitable to evaluate and verify protocols and applications envisioned to utilize this datalink

L-band Digital Aeronautical Communications System (LDACS) draft-maeurer-raw-ldacs-06

This document provides an overview of the architecture of the L-band Digital Aeronautical Communications System (LDACS), which provides a secure, scalable and spectrum efficient terrestrial data link for civil aviation. LDACS is a scheduled, reliable multi-application cellular broadband system with support for IPv6. LDACS shall provide a data link for IP network-based aircraft guidance. High reliability and availability for IP connectivity over LDACS are therefore essential

Validation of Simulated Synthetic Air Traffic against Recorded Air Traffic in Germany

At the heart of the modern air traffic management system there is the communication infrastructure that enables efficient aircraft guidance and safe separation in all phases of flight. However, although current systems are mature and generally providing a good service, they are suffering from the VHF band’s increasing saturation in high density areas. The EU and US, representing the two areas experiencing the most pressure, strive therefore for the sustainable modernization of the aeronautical communication infrastructure. Air traffic management communication shall transition from analog VHF voice communication to more spectrum efficient digital data communication supported by automated decisions of computer systems. This digitization of the air-ground communications infrastructure has to be evaluated carefully against the expected future air traffic to ascertain its sustainability and future-proofness. The accepted approach to this endeavor is to employ large-scale computer simulations. The most used method - generating synthetic air traffic with simplified flight trajectories from extrapolated flight plan databases - is largely accepted by the community as a good compromise between constant aircraft populations (too simplistic) and recorded real-world data (not available for the future). A combination of great-circle routes and simplified altitude profiles is deemed to provide sufficient fidelity for the simulation of long-range communication systems. However, the validity of this approach has yet to be investigated in detail. Although this investigation is certainly not possible in the general case we think that it can be performed for selected areas. In this paper we investigate the validity of synthetic air traffic generation for aeronautical communication system evaluation by comparing the results of our FACTS2 simulator to recorded flight data of Germany. FACTS2 is the German Aerospace Center's framework for aeronautical communication system evaluation

L-band Digital Aeronautical Communications System (LDACS) draft-maeurer-raw-ldacs-04

This document provides an overview of the architecture of the L-band Digital Aeronautical Communications System (LDACS), which provides a secure, scalable and spectrum efficient terrestrial data link for civil aviation. LDACS is a scheduled, reliable multi-application cellular broadband system with support for IPv6. LDACS shall provide a data link for IP network-based aircraft guidance. High reliability and availability for IP connectivity over LDACS are therefore essential

L-band Digital Aeronautical Communications System (LDACS) draft-ietf-raw-ldacs-03

This document provides an overview of the architecture of the L-band Digital Aeronautical Communications System (LDACS), which provides a secure, scalable and spectrum efficient terrestrial data link for civil aviation. LDACS is a scheduled, reliable multi-application cellular broadband system with support for IPv6. LDACS shall provide a data link for IP network-based aircraft guidance. High reliability and availability for IP connectivity over LDACS are therefore essential

L-band Digital Aeronautical Communications System (LDACS) draft-ietf-raw-ldacs-09

This document gives an overview of the architecture of the L-band Digital Aeronautical Communications System (LDACS), which provides a secure, scalable and spectrum efficient terrestrial data link for civil aviation. LDACS is a scheduled, reliable multi-application cellular broadband system with support for IPv6. LDACS provides a data link for IPv6 network-based aircraft guidance. High reliability and availability for IP connectivity over LDACS, as well as security, are therefore essential

Performance-optimizing Secure GBAS over LDACS

VHF Data Broadcast (VDB) currently used by GBAS has been identified as a potential source of cyber-security concerns. The use of an alternative datalink providing the bandwidth for more capable security protocols has therefore been proposed and demonstrated on the basis of the L-band Digital Aeronautical Communication System (LDACS). However, the first demonstration of secure GBAS over LDACS suffered from some performance degradation. This paper provides an improved method for secure GBAS over LDACS on the basis of a rigid performance analysis. Optimized parameters are derived and evaluated. The results point the way for further performance enhancements for even more challenging GBAS scenarios

Improving Usable LDACS Data Rate via Certificate Validity Optimization

Since the beginning of the century, an increasing amount of air traffic has pushed current aeronautical communication systems to their limits. Therefore, a modernization process is ongoing, envisioning to digitalize previously analog systems and prepare them for future requirements. Among these efforts is the L-Band Digital Aeronautical Communications System (LDACS), which is a cellular broadband digital data link system, foreseen for regularity-of-flight and safety-communications. Any newly developed system must provide strong cybersecurity, especially when deployed within critical infrastructures. Similar to other communication systems, LDACS will utilize digital certificates within its Public Key Infrastructure (PKI). Such certificates must be available to the respective communication partner, and therefore might have to be transmitted via the radio link upon first contact. With bandwidth generally being a restricting factor in wireless communication, especially in the spectrum-scarce Lband different certificate lifetimes have varying impacts on the amount of security data. In previous research work, reduction of the LDACS security overhead has already been considered in e.g., the secure cell-attachment procedure between ground and aircraft stations or within a proposal for the utilization of group key distribution procedures in LDACS. However, the effect of different certificate lifetimes on the amount of security data and therefore the available user data rate has not been investigated so far. The objective of this paper is to compare different approaches for certificate validity periods in respect to the additional network overheads being created. Computer simulations using historical flight data from the OpenSky Network and a dedicated LDACS simulator help identifying the most effective solution

Group Key Distribution Procedures For The L-Band Digital Aeronautical Communications System (LDACS)

Since the beginning of the century, an increasing amount of air traffic has pushed current aeronautical communication systems to their limits. Therefore, a modernization process is ongoing aiming to digitalize previously analog systems and prepare them for future requirements. Among these efforts is the L-Band Digital Aeronautical Communication System (LDACS). Being the worldwide first integrated Communication, Navigation and Surveillance (CNS) system, it will replace legacy analog voice communications in the future. Any newly developed system must provide strong cyber security, especially when deployed within critical infrastructures. While previous work has been focused on implementing Mutual Authentication and Key Establishment protocols in LDACS, applying security mechanisms in a group wise fashion has not been evaluated yet. As LDACS control messages apply to all members of an LDACS cell, Group Key Management (GKM) methods are a vital step in introducing control channel security to LDACS. The objective of this paper is to evaluate GKM procedures to support secure group communication within LDACS control channels

L-band Digital Aeronautical Communications System (LDACS) draft-ietf-raw-ldacs-11

This document gives an overview of the architecture of the L-band Digital Aeronautical Communications System (LDACS), which provides a secure, scalable and spectrum efficient terrestrial data link for civil aviation. LDACS is a scheduled, reliable multi-application cellular broadband system with support for IPv6. LDACS provides a data link for IPv6 network-based aircraft guidance. High reliability and availability for IP connectivity over LDACS, as well as security, are therefore essential. The intent of this document is to introduce LDACS to the IETF community, raise awareness on related activities inside and outside of the IETF, and to seek expertise in shaping the shift of aeronautics to IP