This paper provides an overview of the activities performed by Thales Alenia Space Italy (TAS-I) to evaluate the system capacity required for a satellite system to support the Future Railway Mobile Communication System (FRMCS) service in Europe. Georeferenced railway communication traffic, emulated by the Paris Lodron University of Salzburg (PLUS) starting from FRMCS use cases and transportation databases, has been fed into a software tool developed in-house and implementing capacity evaluation algorithms. Multiple scenarios, based upon recent efforts aimed at comparing different solutions for FRMCS servicing via satellite [1], have been investigated. The analysis performed quantifies the amount of cumulative data traffic and spectrum resources required by the satellite system, a prerequisite information to assess its feasibility and substantiate the opportunity for further development.

Air traffic control officers (ATCOs) are specialized workers responsible to monitor and guide airplanes in their assigned airspace. Such a task is highly visual and mainly supported by 2D visualizations. In this paper, we designed and assessed an application for visualizing air traffic in both orthographic (2D) and perspective (3D) views. A user study was then performed to compare these two types of representations in terms of situation awareness, workload, performance, and user acceptance. Results show that the 3D view yielded both higher situation awareness and less workload than the 2D view condition. However, such a performance does not match the opinion of the ATCOs about the 3D representation.

The Airborne Internet is a vision of a large-scale multihop wireless mesh network consisting of commercial passenger aircraft connected via long-range highly directional air-to-air radio links. We propose a geographic load sharing strategy to fully exploit the total air-to-ground capacity available at any given time. When forwarding packets for a given destination, a node considers not one but a set of next-hop candidates and spreads traffic among them based on queue dynamics. In addition, load balancing is performed among Internet Gateways by using a congestion-aware handover strategy. Our simulations using realistic North Atlantic air traffic demonstrate the ability of such a load sharing mechanism to approach the maximum theoretical throughput in the network.

The Airborne Internet is a vision of a large scale multihop wireless mesh network consisting of commercial passenger aircraft connected via long range highly directional air-to-air radio links. We propose a geographic load sharing strategy to fully exploit the total air-to-ground capacity available at any given time. When forwarding packets for a given destination, a node considers not one but a set of next hop candidates, and spreads traffic among them based on queue dynamics. In addition, load balancing is performed among Internet Gateways by using a congestion-aware handover strategy. Our simulations using realistic North Atlantic air traffic reveal the potential of such a load sharing mechanism to approach the maximum theoretical throughput in the network.

The Airborne Internet is envisioned to be a large scale multihop wireless mesh network of commercial passenger aircraft connected via long range highly directional air-to-air radio links. We propose a localized geographic load sharing technique to mitigate congestion in this network, taking into account the underlying link scheduling constraints with directional antennas. When forwarding packets for a given destination, a node considers not one but a set of next hop candidates, and spreads traffic among them based on queue dynamics. Our simulations show that introducing this flexibility in the routing function can greatly increase a node's ability to satisfy its bandwidth demands during link scheduling, yielding significant performance improvements in terms of network throughput and average packet delay.

Aeronautical ad hoc networks represent a special type of ad hoc wireless networks, given their significantly larger scale and the distinct characteristics of their mobile nodes. Aircraft populate the international airspace very heterogeneously. Some regions experience highly dense air traffic, with aircraft headings being largely uncorrelated. Other regions remain only very sparsely populated, with aircraft typically flying parallel to each other. Moreover, the number of airborne aircraft in a given region changes significantly throughout the day. In this paper, we focus on the densely populated European airspace, and investigate the topological behavior of multihop ad hoc wireless networks formed by air-air links of varying communications range. We derive analytical expressions for various topological aspects, such as the lifetime of inter-aircraft links, and the projected hop length using greedy forwarding. These results are in good agreement with the behavior observed in our simulations of the European air traffic scenario. In addition, we assess the performance of greedy forwarding in the aero-nautical environment and show that, under moderate connectivity, this technique delivers almost all packets to their destinations with a minimum hop count.

In the near future, broadband air-ground (A/G) communications will be used by civil aviation aircraft flying over crowded continental areas such as Europe and North America to access a variety of services, ranging from safety- of-life to infotainment applications. This paper investigates the feasibility of extending this coverage via air-air (A/A) multihop communications over oceanic, remote and polar regions, where no such infrastructure is available, so that aircraft flying over these areas can access the ground services without having to use an expensive high-delay satellite link. We focus on a particularly attractive scenario, the North Atlantic Corridor, and use realistic flight data to extract statistics about the dynamic topology of the airborne ad hoc network, such as connectivity and link stability. In addition, we assess the performance of greedy forwarding in the aeronautical environment and show that, under moderate connectivity, this technique delivers almost all packets to their destinations with a minimum hop count.

MobilitY and CollAboRative Work in European Vehicle Emergency NeTworks (MYCAREVENT)1 is an European Project of the 6th Framework Program [1]. MYCAREVENT aims to optimize the European market for automotive services and repair. MYCAREVENT develops and implements new applications and services, which can be seamlessly and securely, accessed using mobile communication. Maintenance situations like car breakdowns or minor failures will happen everywhere. Wherever such an unpleasant situation appears, the driver needs help and advice. The help most likely will be a roadside assistant. MYCAREVENT provides the roadside technician and the driver with mobile communication following an "always best connected" approach to facilitate the communication between the mobile users within a collaborative work environment. This paper presents the MYCAREVENT project and its communication architecture concept.

MobilitY and CollAboRative Work in European Vehicle Emergency NeTworks (MYCAREVENT) is an European Project of the 6th Framework Program [1], and aims to optimize the European market for automotive after sales services and repair. MYCAREVENT develops innovative applications and services, which can always be accessed seamlessly and securely using mobile communication. Maintenance situations like car breakdowns or minor failures happen everywhere. Wherever such an unpleasant situation appears, the driver needs help and advice - most likely provided by a roadside patrol. To support roadside technicians and drivers with MYCAREVENT products and services, a mobile communication following an "always best connected" approach facilitates the communication between the mobile users within a collaborative work environment. This paper presents the vehicle communication gateway (VCG) and its protocol architecture developed in MYCAREVENT.

The analytical methods and the analysis as well as the simulative tools developed for the performance evaluation and validation of the dedicated vehicle-roadside short-range communication (DSRC) protocols proposed for standardization in Europe (CEN/TC 278/WG9) and in North America are presented. First, the basic concept of the medium access control protocol for vehicles entering the communication zone of a roadside beacon is described. Then, the analytical methods and tools (MARCO) for medium access using new multi-level Markov chain models are presented, in which the dynamic arrival of up to n vehicles and the completion of the full transaction (AFC, automatic fee collection) is taken into account. Furthermore, the characteristics of the two simulative tools SIMCO-F/DSRC and SIMCO3++/DSRC are described. These tools are validated by comparison of the analytical results of the MARCO tool with the results of the simulative tools. Finally, the advantages/disadvantages and the recommended usage of these methods and tools for the validation of the dedicated vehicle-roadside short-range communications proposed for standardization as well as for the DSRC system calibration are discussed.

A proposal for a communication architecture for road transport telematics (RTT) infrastructure networks is presented. First, the technical approach which has been set up to cope with the relevant subjects is introduced. Then, the communication requirements of RTT applications are considered. Following that, the protocol profile is defined which includes a protocol stack for the vehicle-roadside communications via beacons (DSRC). Thereupon, the protocol evaluation and the co-operation between the beacons and the fixed network ape discussed. Finally, the performance analysis of medium access control (MAC) protocols for the DSRC and for the fixed network are addressed.>