Alain Pirovano

Aeronautical Ad Hoc Network for Civil Aviation

Aeronautical communication systems are constantly evolving in order to handle the always increasing flow of data generated by civil aviation. In this article we first present communication systems currently used for en-route aircraft. We then propose Aeronautical Ad hoc NETwork (AANET) as a complementary communication system and demonstrate its connectivity and assess the throughput by simulations based on real aircraft trajectories over the French sky and over the Atlantic ocean.

An aeronautical data link security overview

This paper reviews existing security mechanisms for aeronautical data link communication: current support and availability of such features are described. With an Open Systems Interconnection (OSI) reference model-driven analysis, each solution is classified and analyzed according to the layer where security is deployed and a relevant taxonomy is proposed. Moreover, advantages, drawbacks, and possible threats of every security mechanisms previously introduced are discussed. According to this security infrastructure overview, a proposal for an efficient security architecture adapted to the aeronautical context is made for future studies. Satellite communication-based system specific problematic is taken into account with a constraint bandwidth and the need of reduced overhead for any additional mechanisms.

A New Survey on Improving TCP Performances over Geostationary Satellite Link

The idea of Internet everywhere makes the assumption that an Internet access should be available even in remote areas without network infrastructure. In this case satellite access represents an attractive solution. Nevertheless, experience shows that over satellite links, TCP is limited in terms of data speeds. Many enhancements and solutions, based for instance on tuning TCP parameters or TCP spoofing, have been proposed to avoid the underutilization of satellite link capacity. These topics have been often addressed, but considering recent high speed TCP variants, the evolution of end users habits, and recently proposed satellite link access scheme, a new study is necessary in order to reconsider some preconceptions and previous recommendations in such a context. This paper proposes an overview of TCP variants and a survey of commonly proposed solutions for TCP over satellite. Then a methodology for TCP performance assessment over satellite links is exposed. The approach is mainly based on a satellite link emulation platform and some tools developed at the ENAC. We assess the gain offered by a split TCP connection with PEPSal comparatively to end to end TCP connections based on NewReno and a recent widely deployed TCP version (TCP Cubic) on an emulated satellite link. Unlike existing studies, we compare PEP advantages with most recent TCP versions and propose as an extension, to assess PEP gain considering the number of simultaneous TCP connections. Finally, the results provided allow us to make some original recommendations toward TCP deployment over satellite links.

Wireless Ad Hoc Networks Access For Aeronautical Communications

There is an increasing interest in the current aeronautical context to offer new services for civil aircraft passengers. For example, airlines want to offer their customers the opportunity to access the Internet, to manage their mails, to watch video on demand, to access corporate VPNs.... All these services represent a new type of air-ground communications called APC (Aeronautical Passenger Communications) in the ATN (Aeronautical Telecommunication Network) context. In this paper, we will show how an aeronautical ad hoc access network and satellite links can be used simultaneously for these communications.

Survey on Context-Aware Publish/Subscribe Systems for VANET

The publish / subscribe scheme is an efficient paradigm for communication widely used in wired networks. However the use of this paradigm in the context of mobile networks such as VANETs is still an open research topic. In particular, the communication needs of mobile nodes often depend on the node state, location and/or surroundings. Consequently, extensions to the P/S paradigm have been proposed that introduce the concept of node context. This paper propose a survey on these context-aware publish / subscribe solutions for VANETs. We will particularly focus our discussion on two example applications drawn from the context of civil aviation and will argue that Aeronautical Ad hoc Networks (AANETs) are a subgroup of VANETs.

Interference estimation in an aeronautical ad hoc network

Recent research have considered aeronautical ad hoc networks as a possible mean for future aeronautical communications. By introducing inter-aircraft links, they are supposed to become an alternative to existing solutions based on direct air-ground or satellite links. In this paper, we propose the use of asynchronous Code Division Multiple Access (CDMA) in aeronautical ad hoc networks. We then present a simulation model developed with OPNET Modeler that estimates the impact of Multiple Access Interference (MAI) on packets delivery. Finally, we give the results of some simulations made with an ATC/AOC traffic model, and with real aircraft positions over the French sky.

Aeronautical communication transition from analog to digital data: A network security survey

Abstract The objective of this paper is to present a comprehensive survey of security challenges in aeronautical data communication networks. The civil aviation industry is currently going through an evolution of the air traffic management system. The aviation communication technologies are progressively shifting towards the use of digital data instead of analog voice for traffic control, airline business, and passenger onboard entertainment systems. This paper illustrates the cause-to-effect chain link starting from the modernization of the aeronautical communication systems and leading to the network security concern in the civil aviation. The general threats to air–ground communication are depicted and then categorized. The paper gives an overview of the civil aviation industry efforts for securing the future aeronautical data communications. The security mechanisms and protocols proposed for this purpose are discussed. Open research issues and challenges that have to be addressed in the security of current and future aeronautical data communication networks are presented in detail. The paper concludes with some improvement directions which can help to address those security issues. This survey can be used as a reference guide to first understand the factors that urge both the research community and the aviation industry to be concerned about network security in future aeronautical data communications. Also, it can be used as a first reading to have a global overview of network security issues, challenges and potential solutions in air–ground communication networks.

Performance Analysis of Routing Algorithms in AANET with Realistic Access Layer

Aeronautical Ad-hoc NETworks AANETs have been studied and could be proposed as an complementary communication system for civil aviation. Several routing algorithm have been proposed and assessed through simulation, but there is a lack of evaluation in realistic conditions, especially regarding the access layer. In this paper we propose to use Random Packet CDMA RP-CDMA as a MAC layer protocol for AANETs. We then present the results of simulations with actual aircraft trajectories considering successively three well-known routing algorithm namely AODV, DYMO and BATMAN. We conclude from these simulations that AODV has the best performances, but also that the realistic access layer is quickly saturated by the mere signalization traffic. This calls for improvements in both routing algorithms and access layer.

Routing in aeronautical ad-hoc networks

Routing is one of the main challenges that Aeronautical Ad-hoc NETworks (AANETs) are facing, mostly because of the mobility of the nodes, the geographic size of the network and the number of nodes. To handle this problem, we propose in this paper an innovative routing algorithm called NoDe-TBR (Node Density-TBR), derived from Trajectory-Based Routing (TBR). In this routing algorithm, each aircraft computes a geographic path between itself and the destination of its message. In order to improve delivery probability, this path takes into account the actual aircraft density in each area. The performances of this algorithm have been assessed through simulations, with replayed aircraft trajectories over the North Atlantic Tracks (NATs). They are compared to the performances of classic routing algorithms designed for Mobile Ad-hoc NETworks (MANETs). Our solution exhibits better performances than classic routing protocols, but for a fraction of the signalization traffic volume. This is particularly desirable in resource-constraint networks such as AANETs.

Fiber-like Aircraft Satellite Communications: FAST, an Aerospace Valley project. System architecture and protocol stack design

Aeronautical communications systems are experiencing a fast evolution due to digital migration which demands new perspectives and solutions in order to define a reliable data link communication. This paper presents a project called FAST: Fiber-like Aircraft Satellite communications. The project is funded by Aerospace Valley (a competitiveness cluster for aeronautics, space and embedded systems) in France and gathers industrial and academic partners. The objective is to design a versatile sa tellite communication system and to develop and demonstrate key technologies (active antenna, proxies’ software ...). A focus will be placed in this paper on the global system design, t he definition of supported services and the network and protocols structure. The main challenge is to converge heterogeneous traffics on the same satellite link with high reliability an d availability. The proposed services cover classical aeronautical communications ATC/AOC along with “new generation” services such as telemedicine and On-board Security surveillance.