Dans un contexte de besoins croissants de moyens de communication pour augmenter la sécurité des vols et répondre aux attentes des compagnies et des passagers, le monde de l’aviation civile cherche de nouveaux systèmes de communication pouvant répondre à ces objectifs. Les systèmes de communication sol-bord existants, que ce soit les solutions par satellites en bande L (SATCOM, ...) ou les solutions cellulaires par liaison directe avec le sol (HF, VHF, ...), présentent des limites en terme de capacité, de couverture et de coût.La proposition avancée dans le cadre de cette thèse est d’utiliser les avions comme relais afin de propager les données jusqu’à une station sol. Ce système peut être vu comme un réseau ad hoc mobile dont les nœuds sont les avions civils en vol. Grâce à plusieurs sauts successifs au travers d’avions relais, chaque avion doit pouvoir joindre le sol sans être à portée directe d’une station. Le réseau ad hoc ainsi formé peut ensuite être utilisé pour différentes classes de communications : contrôle aérien, services pour les compagnies aériennes ou pour les passagers. Une telle solution permettrait d’améliorer la couverture des solutions cellulaires classiques en zone continentale. Elle est également applicable en zone océanique où les seuls moyens disponibles sont actuellement le satellite et la HF. On peut imaginer que les coûts de déploiement et de maintenance seraient relativement bas puisque l’infrastructure sol est limitée.Dans cette thèse, nous avons étudié la faisabilité puis les performances qui peuvent être attendues pour ce système de communication aéronautique innovant. / In the current aeronautical communications context, there is an increasing interest in offering new services to civil aircraft. For instance, airlines are looking into new solutions to back up flight data and cockpit voice records during the flight, or to provide more accurate meteorological data to pilots. Being able to offer Internet access to passengers is also a major demand from these companies. All these services represent new types of air-ground communications that require newcommunication systems. Indeed, traditional datalink systems are based on a direct airground link (e.g. VDL Mode 2) or on a satellite link (e.g. L-Band Inmarsat satellites).They all have limits in terms of capacity, coverage and cost. In this thesis, we study aeronautical ad hoc networks. They have recently been proposedas a new solution for future air-ground communications. The idea of such networks is to introduce wireless links between aircraft. This system can be seen as a mobile ad hoc network whose nodes are civil aircraft in flight. Each aircraft is able to act as a router to send data hop-by-hop to the destination. Such a solution would improve the coverage of conventional cellular solutions in continental area. It is also applicable to oceanic areas, where the only available solutions are now satellite and HF. The costs of deployment and maintenance would be relatively low because the ground infrastructure is limited. In this thesis, the feasibility of this innovative aeronautical communication system is investigated. A simulation tool has been developed to study the network connectivity, based on actual aircraft positions data both in continental and oceanic airspace.

Zugl.: Freiburg (Breisgau), Univ., Diss., 2007.

ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / As part of Morgan’s iNET development, the Mixed Cellular and Mobile Ad hoc Network (MCMN) architecture has been 1proposed to provide coverage to over-the horizon test articles. Nodes in MCMN are assigned to one of three possible modes- Ad hoc, Cellular or Gateway. We present architecture for the proposed MCMN and some performance analysis to characterize the network. The problem of organizing nodes in this mixed network with optimal configuration is significant. This configuration gives nodes ability to know the best mode to operate and communicate with other nodes. Node organization is critical to the performance of the mixed network and to improve communication. The configuration of nodes required to optimally organize nodes in MCMN is demonstrated. The problem of evaluating configuration parameters for nodes in a mixed network is a nonlinear and complex one. This is due to the various components like the number of nodes, geographical location, signal strength, mobility, connectivity and others that are involved. Clustering techniques and algorithms have been used in literature to partition networks into clusters to support routing and network management. A clustering technique is employed to dynamically partition the aggregate network into Cluster Cells (CCs). A gateway node is selected for each CC which relays traffic from the cellular to the Ad hoc and vice versa. A trade-off analysis of the cellular boundary is presented using the maximum of the minimum data rate in the network. Numerical analysis and experiments are provided to show that the coverage can be extended to test articles in over-the-horizon region. It is also shown that, when the network is well organized, performance is improved.

ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / In the iNET community, communications between Test Articles (TA) and Ground Station (GS) can be over a long distance course that places a TA at ranges where they are sometimes beyond line-of-sight (LoS) or over-the-horizon communications with the GS. In other cases, the TA moves out of the LoS communications range of GS. There is a need to provide communications to these TA at these over-the-horizon locations. The Cellular and Mobile Ad Hoc Network (MANET) have attracted a lot of attention recently and the field continues to grow daily. The cellular network offers high capacity but limited in coverage due to its fixed base infrastructure. MANET on the other hand has a wide range of coverage and also high data rates, but its throughput performance is reduced at high capacity. The MANET cellular mixture network (MCMN) has been proposed to provide an extensive communications between the TA and GS in the iNET environment. This work presents a performance evaluation and analysis of the two different networks with respect to the performance needs of iNET environment which include coverage and throughput.

The research study determines OPNET simulation to evaluate the MANET routing protocols i.e. AODV, DSR, GRP and OLSR performance for HTTP and FTP base application traffic. Results from the simulation result helps to measure the performance matrix i.e. packet delivery fraction, normalized routing load, throughput and end to end delay. Scalar values are extracted from simulation to plot desired performance graphs to analyze. The research results and conclusion produces enough information for the selection of best routing protocol for MANET in terms of HTTP and FTP application types.

Mobile Ad hoc Network of Networks (MANoN) are a group of large autonomous wireless nodes communicating on a peer-to-peer basis in a heterogeneous environment with no pre-defined infrastructure. In fact, each node by itself is an ad hoc network with its own management. MANoNs are evolvable systems, which mean each ad hoc network has the ability to perform separately under its own policies and management without affecting the main system; therefore, new ad hoc networks can emerge and disconnect from the MANoN without conflicting with the policies of other networks. The unique characteristics of MANoN makes such networks highly vulnerable to security attacks compared with wired networks or even normal mobile ad hoc networks. This thesis presents a novel security-management system based upon the Recommendation ITU-T M.3400, which is used to evaluate, report on the behaviour of our MANoN and then support complex services our system might need to accomplish. Our security management will concentrate on three essential components: Security Administration, Prevention and Detection and Containment and Recovery. In any system, providing one of those components is a problem; consequently, dealing with an infrastructure-less MANoN will be a dilemma, yet we approached each set group of these essentials independently, providing unusual solutions for each one of them but concentrating mainly on the prevention and detection category. The contributions of this research are threefold. First, we defined MANoN Security Architecture based upon the ITU-T Recommendations: X.800 and X.805. This security architecture provides a comprehensive, end-to-end security solution for MANoN that could be applied to every wireless network that satisfies a similar scenario, using such networks in order to predict, detect and correct security vulnerabilities. The security architecture identifies the security requirements needed, their objectives and the means by which they could be applied to every part of the MANoN, taking into consideration the different security attacks it could face. Second, realising the prevention component by implementing some of the security requirements identified in the Security Architecture, such as authentication, authorisation, availability, data confidentiality, data integrity and non-repudiation has been proposed by means of defining a novel Security Access Control Mechanism based on Threshold Cryptography Digital Certificates in MANoN. Network Simulator (NS-2) is a real network environment simulator, which is used to test the performance of the proposed security mechanism and demonstrate its effectiveness. Our ACM-MANoN results provide a fully distributed security protocol that provides a high level of secure, available, scalable, flexible and efficient management services for MANoN. The third contribution is realising the detection component, which is represented by providing a Behavioural Detection Mechanism based on nodes behavioural observation engaged with policies. This behaviour mechanism will be used to detect malicious nodes acting to bring the system down. This approach has been validated using an attacks case study in an unknown military environment to cope with misbehaving nodes.

Le développement d'applications sur réseaux mobiles ad hoc présente des contraintes liées à la mobilité des terminaux, à la nature décentralisée des manets, et aux ressources limitées, et nécessite donc la mise en place d'une algorithmique nouvelle. Cette thèse propose des algorithmes permettant la mise en place d'un système de partage de données sur manet : - un algorithme de création de grappes de terminaux mobiles stables dans le temps, qui présente l'avantage de ne pas utiliser de ressources réseaux (utilisation informations inter-couches). - un algorithme de réplication de données pro-actif, qui maintien un nombre de répliques k proportionnel au nombre de terminaux présents et les place sur les terminaux les plus susceptibles de les utiliser. Cela augmente la disponibilité et la fiabilité du service. - un algorithme de gestion de cache, qui maintient le nombre de répliques au minimum permettant un usage efficace du réseau et offrant une bonne disponibilité. D'une part, il élimine les données utilisées le moins récemment et dont le nombre de répliques est supérieur à k. D'autre part, il diminue la charge réseau en éliminant les répliques de données non utilisées par leur hôte.

In the past decades, mobile traffic generated by devices such as smartphones, iphones, laptops and mobile gateways has been growing rapidly. While traditional direct connection techniques evolve to provide better access to the Internet, a new type of wireless network, mobile ad hoc network (MANET), has emerged. A MANET differs from a direct connection network in the way that it is multi-hopping and self-organizing and thus able to operate without the help of prefixed infrastructures. However, challenges such dynamic topology, unreliable wireless links and resource constraints impede the wide applications of MANETs. Routing in a MANET is complex because it has to react efficiently to unfavourable conditions and support traditional IP services. In addition, Quality of Service (QoS) provision is required to support the rapid growth of video in mobile traffic. As a consequence, tremendous efforts have been devoted to the design of QoS routing in MANETs, leading to the emergence of a number of QoS support techniques. However, the application independent nature of QoS routing protocols results in the absence of a one-for-all solution for MANETs. Meanwhile, the relative importance of QoS metrics in real applications is not considered in many studies. A Best Effort QoS support (BEQoS) routing model which evaluates and ranks alternative routing protocols by considering the relative importance of multiple QoS metrics is proposed in this thesis. BEQoS has two algorithms, SAW-AHP and FPP for different scenarios. The former is suitable for cases where uncertainty factors such as standard deviation can be neglected while the latter considers uncertainty of the problems. SAW-AHP is a combination of Simple Additive Weighting and Analytic Hierarchical Process in which the decision maker or network operator is firstly required to assign his/her preference of metrics with a specific number according to given rules. The comparison matrices are composed accordingly, based on which the synthetic weights for alternatives are gained. The one with the highest weight is the optimal protocol among all alternatives. The reliability and efficiency of SAW-AHP are validated through simulations. An integrated architecture, using evaluation results of SAW-AHP is proposed which incorporates the ad hoc technology into the existing WLAN and therefore provides a solution for the last mile access problems. The protocol selection induced cost and gains are also discussed. The thesis concludes by describing the potential application area of the proposed method. Fuzzy SAW-AHP is extended to accommodate the vagueness of the decision maker and complexity of problems such as standard deviation in simulations. The fuzzy triangular numbers are used to substitute the crisp numbers in comparison matrices in traditional AHP. Fuzzy Preference Programming (FPP) is employed to obtain the crisp synthetic weight for alternatives based on which they are ranked. The reliability and efficiency of SAW-FPP are demonstrated by simulations.

El constante aumento de las capacidades de los dispositivos móviles ha gatillado un aumento significativo del uso de éstos. Adicionalmente ha aumentado la cantidad de tareas que se utilizan estos dispositivos. La idea principal detrás de la mayoría de estas tareas y funcionalidades incorporadas es ahorrarle tiempo valioso al usuario. En el ámbito de las comunicaciones interpersonales el uso de estos dispositivos es especialmente difundido y da origen a este trabajo. La problemática a resolver es facilitar a los usuarios la oportunidad de encontrarse cara a cara en escenarios de baja conectividad tradicional como es la red internet por ejemplo. El sistema desarrollado, que intenta resolver esta problemática planteada, consiste en la creación de una aplicación que se conecta a una red móvil ad hoc, usando Wi-Fi, la cual no requiere la existencia de una infraestructura de comunicaciones entre dispositivos. El usuario de esta aplicación puede crear una lista de contactos (y grupos de éstos) y fijar una alerta sobre alguno de estos. En el momento en que un contacto marcado se encuentre cerca, el dispositivo avisará al usuario de esto. Se consideró que lo desarrollado pudiese funcionar tanto en equipos móviles de tipo Pocket PC como también en notebooks. Inicialmente se investigó sobre herramientas existentes que se utilizarían para construir la solución propuesta y se realizaron varias pruebas. El producto final de este trabajo de título es una aplicación que funciona en dos sistemas operativos distintos (Microsoft Windows XP y Mobile 5), y permite a una persona individualizarse dentro de una red ah hoc, tener sus propios contactos y ser alertado de la cercanía de éstos. El sistema desarrollado permite al usuario dedicarse a tareas más importantes que coordinar un encuentro cara a cara y existen diversos ámbitos en que puede ser utilizado. Otra particularidad del desarrollo es que se generó un código base que es utilizado por ambas plataformas generadas y que de esta forma se dejan abiertas numerosas posibilidades para trabajos futuros en que sólo deberá ser modificada esta base para lograr las mejoras deseadas en las plataformas mencionadas.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.