The Airborne Internet

Mineralogy & gem

Chapter The Airborne Internet

Mineralogy & gem

Capacity Dimensioning for Aeronautical Communications in North Atlantic Corridor

In the context of the Internet everywhere paradigm, aircraft passengers expect to get connectivity during flights. Several solutions based either on cellular networks in continental area or on satellite links have been designed and even deployed for some of them. But to face the increasing number of users and expected services, a migration to future satellite system such as Inmarsat's Ka band Global Xpress system have been planned. The considered geographical area of the present study is the north Atlantic corridor. In this service zone, the specific structure of aeronautical traffic must be taken into account. NAT (North Atlantic Tracks) are oceanic routes between North America and Europe that are periodically defined considering weather and wind conditions. This explains why the exact locations of the tracks change daily according to weather and also traffic demands. On each continent, specific air traffic control is provided in order to manage entrance and movement along these tracks. The proposed study makes the assumption of a flexible global coverage provided by multi beam Ka band satellites that operate in geosynchronous orbit. Aircraft flying in the north Atlantic corridor use the system in order to offer in-flight connectivity for airline passengers. Doing so, passengers may access common Internet services, namely web browsing, electronic mail, or file transfer. More specific applications for pilots and companies are also taken in consideration enhanced with new services such as real time black box data streaming. In order to assess induced traffic load and instantaneous required capacities in each spot beam, a simulation model has been specifically developed by ENAC and ISAE with Opnet Modeler software

High-Throughput Air-to-Ground Connectivity for Aircraft

Permanent connectivity to the Internet has become the defacto standard in the second decade of the 21st century. However, on-board aircraft connectivity is still limited. While the number of airlines offering in-flight connectivity increases, the current performance is insufficient to satisfy several hundreds of passengers simultaneously. There are several options to connect aircraft to the ground, i.e. direct air-to-ground, satellites and relaying via air-to-air links. However, each single solution is insufficient. The direct air-to-ground coverage is limited to the continent and coastal regions, while the satellite links are limited in the minimum size of the spot beams and air-to-air links need to be combined with a link to the ground. Moreover, even if a direct air-to-ground or satellite link is available, the peak throughput offered on each link is rarely achieved, as the capacity needs to be shared with other aircraft flying in the same coverage area. The main challenge in achieving a high throughput per aircraft lies in the throughput allocation. All aircraft should receive a fair share of the available throughput. More specifically, as an aircraft contains a network itself, a weighted share according to the aircraft size should be provided. To address this problem, an integrated air-to-ground network, which is able to provide a high throughput to aircraft, is proposed here. Therefore, this work introduces a weighted-fair throughput allocation scheme to provide such a desired allocation. While various aspects of aircraft connectivity are studied in literature, this work is the first to address an integrated air-to-ground network to provide high-throughput connectivity to aircraft. This work models the problem of throughput allocation as a mixed integer linear program. Two throughput allocation schemes are proposed, a centralized optimal solution and a distributed heuristic solution. For the optimal solution, two different objectives are introduced, a max-min-based and a threshold-based objective. The optimal solution is utilized as a benchmark for the achievable throughput for small scenarios, while the heuristic solution offers a distributed approach and can process scenarios with a higher number of aircraft. Additionally, an option for weighted-fair throughput allocation is included. Hence, large aircraft obtain a larger share of the throughput than smaller ones. This leads to fair throughput allocation with respect to the size of the aircraft. To analyze the performance of throughput allocation in the air-to-ground network, this work introduces an air-to-ground network model. It models the network realistically, but independent from specific network implementations, such as 5G or WiFi. It is also adaptable to different scenarios. The aircraft network is studied based on captured flight traces. Extensive and representative parameter studies are conducted, including, among others, different link setups, geographic scenarios, aircraft capabilities, link distances and link capacities. The results show that the throughput can be distributed optimally during high-aircraft-density times using the optimal solution and close to optimal using the heuristic solution. The mean throughput during these times in the optimal reference scenario with low Earth orbit satellites is 20 Mbps via direct air-to-ground links and 4 Mbps via satellite links, which corresponds to 10.7% and 1.9% of the maximum link throughput, respectively. Nevertheless, during low-aircraft-density times, which are less challenging, the throughput can reach more than 200 Mbps. Therefore, the challenge is on providing a high throughput during high-aircraft-density times. In the larger central European scenario, using the heuristic scheme, a minimum of 22.9 Mbps, i.e. 3.2% of the maximum capacity, can be provided to all aircraft during high-aircraft-density times. Moreover, the critical parameters to obtain a high throughput are presented. For instance, this work shows that multi-hop air-to-air links are dispensable for aircraft within direct air-to-ground coverage. While the computation time of the optimal solution limits the number of aircraft in the scenario, larger scenarios can be studied using the heuristic scheme. The results using the weighted-fair throughput allocation show that the introduction of weights enables a user-fair throughput allocation instead of an aircraft-fair throughput allocation. As a conclusion, using the air-to-ground model and the two introduced throughput allocation schemes, the achievable weighted-fair throughput per aircraft and the respective link choices can be quantified

Secure Point-to-Point Long-Distance Multi-Hop Connections in a Dense Airplane Mesh-Network using LDACS

The capacity of current aeronautical datalinks is reaching its limits and becomes a hindrance for growth of worldwide civil aviation. To modernize Air Traffic Management (ATM) and digitize aeronautical communications, successors for current technologies are being researched and deployed. The envisioned successor for the VHF Datalink mode 2 (VDLm2) for European air traffic is the L-band Digital Aeronautical Communications System (LDACS). Similar to VDLm2, LDACS is a terrestrial, cellular Air-Ground (A/G) communications system. Contrary to VDLm2, LDACS shall also provide an Air-Air (A/A) communication mode in the future, called LDACS A/A, which operates in a radius of 200 Nautical Miles (NM) for aircraft above altitude of 3000m. Long-distance multi-hop A/A communications could be used to extend the range of LDACS ground stations into oceanic and remote areas, increasing the utility of the terrestrial infrastructure. While LDACS A/G offers sound cybersecurity measures, the development of such for an LDACS A/A extension is currently in its infancy and needs to be investigated thoroughly. One particular design constraint for cybersecurity for aeronautical multi-hop A/A networks is the topology of the underlying mesh network. The objectives of this paper are to investigate (1) the number of concurrent aircraft that are within communication range to each other and (2) the number of hops necessary to cover given distances and (3) to propose possible cybersecurity approaches for LDACS A/A in particular. With actual flight traces data from the OpenSky database for European air traffic, we identify high fluctuations of results based on the time of day and region. The following results were obtained: (1) concurrent aircraft are ranging from 0 to 258, (2) on an exemplary route from Istanbul to Dublin, ranging roughly 3000km, 9 hops were necessary on average with stable routes lasting 1m 21s on average and (3) up to 19% of the total stable connection time is used for establishing a secure Peer-to-Peer (P2P) tunnel via mutual authentication between all hops

Internet of Unmanned Aerial Vehicles: QoS Provisioning in Aerial Ad-Hoc Networks

Aerial ad-hoc networks have the potential to enable smart services while maintaining communication between the ground system and unmanned aerial vehicles (UAV). Previous research has focused on enabling aerial data-centric smart services while integrating the benefits of aerial objects such as UAVs in hostile and non-hostile environments. Quality of service (QoS) provisioning in UAV-assisted communication is a challenging research theme in aerial ad-hoc networks environments. Literature on aerial ad hoc networks lacks cooperative service-oriented modeling for distributed network environments, relying on costly static base station-oriented centralized network environments. Towards this end, this paper proposes a quality of service provisioning framework for a UAV-assisted aerial ad hoc network environment (QSPU) focusing on reliable aerial communication. The UAV’s aerial mobility and service parameters are modelled considering highly dynamic aerial ad-hoc environments. UAV-centric mobility models are utilized to develop a complete aerial routing framework. A comparative performance evaluation demonstrates the benefits of the proposed aerial communication framework. It is evident that QSPU outperforms the state-of-the-art techniques in terms of a number of service-oriented performance metrics in a UAV-assisted aerial ad-hoc network environment

Study of the benefits and applications of LEO (Low Earth Orbit) for Communications and definition of space new business models. Case study: Telesat

Having a quality connectivity service is key in the economic, educational and health development of today’s society. However, current communication systems are not capable of providing full community connectivity, leaving the most remote areas underserved. This project analyzes how the Telesat satellite operator, through its Telesat Lightspeed constellation, proposes a business model based on deploying 298 satellites in low Earth orbits (LEO) to face the most demanding telecommunications challenges, and close the digital divide between urban and rural communities by delivering a universal, fast and affordable internet service. Therefore, studying the benefits and applications of low Earth orbits, analyzing the characteristics of Telesat and its constellation of satellites, as well as examining how it intends to carry out its value proposition and the risks it faces, are the main points on which this thesis is based

Increasing service visibility for future, softwarised air traffic management data networks

Air Traffic Management (ATM) is at an exciting frontier. The volume of air traffic is reaching the safe limits of current infrastructure. Yet, demand for more air traffic continues. To meet capacity demands, ATM data networks are increasing in complexity with: greater infrastructure integration, higher availability and precision of services; and the introduction of unmanned systems. Official recommendations into previous disruptive outages have high-lighted the need for operators to have richer monitoring capabilities and operational systems visibility, on-demand, in response to challenges. The work presented in this thesis, helps ATM operators better understand and increase visibility into the behaviour of their services and infrastructure, with the primary aim to inform decision-making to reduce service disruption. This is achieved by combining a container-based NFV framework with Software- Defined Networking (SDN). The application of SDN+NFV in this work allows lightweight, chain-able monitoring and anomaly detection functions to be deployed on-demand, and the appropriate (sub)set of network traffic routed through these virtual network functions to provide timely, context-specific information. This container-based function deployment architecture, allows for punctual in-network processing through the instantiation of custom functionality, at appropriate locations. When accidents do occur, such as the crash of a UAV, the lessons learnt should be integrated into future systems. For one such incident, the accident investigation identified a telemetry precursor an hour prior. The function deployment architecture allows operators to extend and adapt their network infrastructure, to incorporate the latest monitoring recommendations. Furthermore, this work has examined relationships in application-level information and network layer data representing individual examples of a wide range of generalisable cases including: between the cyber and physical components of surveillance data, the rate of change in telemetry to determine abnormal aircraft surface movements, and the emerging behaviour of network flooding. Each of these examples provide valuable context-specific benefits to operators and a generalised basis from which further tools can be developed to enhance their understanding of their networks