International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / A large selection of hardware and software components are readily available for supporting Internet communication in the ground network environment. These components can be used to construct very powerful and flexible communication systems. The Operating Missions as Nodes on the Internet (OMNI) project at NASA/GSFC has been defining and demonstrating ways to use standard Internet technologies for future space communication. Theses concepts and technologies are also applicable to test range telemetry applications. This paper identifies the network equipment and protocols to support end-to-end IP communication from range sensors and spacecraft instruments to end users. After identifying the end-to-end network hardware and software components, the paper discusses which ones are currently available and lists specific examples of each. This includes examples of space missions currently using Internet technology for end-to-end communication. It also lists missing pieces and includes information on their current status. The goal of this paper is also to stimulate thought and discussion on what steps need to be taken to start filling in the remaining missing pieces for end-to-end range and space network connectivity.

International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / This paper presents work being done at NASA/GSFC by the Operating Missions as Nodes on the Internet (OMNI) project to demonstrate the application of Internet communication technologies to space communication. The goal is to provide global addressability and standard network protocols and applications for future space missions. It describes the communication architecture and operations concepts that will be deployed and tested on a Space Shuttle flight in July 2002. This is a NASA Hitchhiker mission called Communication and Navigation Demonstration On Shuttle (CANDOS). The mission will be using a small programmable transceiver mounted in the Shuttle bay that can communicate through NASA’s ground tracking stations as well as NASA’s space relay satellite system. The transceiver includes a processor running the Linux operating system and a standard synchronous serial interface that supports the High-level Data Link Control (HDLC) framing protocol. One of the main goals will be to test the operation of the Mobile IP protocol (RFC 2002) for automatic routing of data as the Shuttle passes from one contact to another. Other protocols to be utilized onboard CANDOS include secure login (SSH), UDP-based reliable file transfer (MDP), and blind commanding using UDP. The paper describes how each of these standard protocols available in the Linux operating system can be used to support communication with a space vehicle. It will discuss how each protocol is suited to support the range of special communication needs of space missions.

Each day, Humanity loses thousands of persons on roads when they were traveling to work, to study or even to distract. The financial cost of these injuries is also terrifying: Some statistics evaluate the financial cost of vehicle accidents at 160 billion Euro in Europe each year. These alarming figures have driven researchers, automotive companies and public governments to improve the safety of our transportation systems and communication technologies aiming at offering safer roads and smooth driving to human beings. In this context, Vehicular Adhoc Networks, where vehicles are able to communicate with each others and with existent road side units, emerge as a promising wireless technology able to enhance the vision of drivers and offer larger telematic horizon. VANETs promising applications are not only restricted to road safety but span from vehicle trafficoptimization like flow congestion control to commercial applications like file sharing and internet access. Safety applications require that their alert information is propagated to the concerned vehicles (located in the hazardous zone) with little delay and high reliability. For these reasons, this category of applications is considered as delay sensitive and broadcast-oriented nature. While classical blind flooding is rapid, its major drawback is its huge bandwidth utilization. In this thesis, we are interested on enhancing vehicular communications under different scenarios and optimizations: First, We focus on deriving a new solution (EBDR) to disseminate alert messages among moving vehicles while maintaining it efficient and rapid. Our proposal is based on directional antennas to broadcast messages and a route guidance algorithm to choose the best path for the packets. Findings confirmed the efficiency of our approach in terms of probability of success and end-to-end delays. Moreover, in spite of the broadcast nature of the proposed technique, all transmissions stop very soon after the arrival of a packet to its destination representing a strong feature in the conception of EBDR. Second, we propose a novel mathematical framework to evaluate the performance of EBDR analytically. Although most of the proposed techniques present in literature use experimental or simulation tools to defend their performance, we rely here on mathematical models to confirm our achieved results. Our proposed framework allows to derive meaningful performance metrics including the probability of transmission success and the required number of hops to reach thefinal destination. Third, we refine our proposed broadcast-based routing EBDR to provide more efficient broadcasting by adjusting the transmission range of each vehicle based on its distance to the destination and the local node density. This mechanism allows better minimization of interferences and bandwidth's saving. Furthermore, an analytical model is derived to calculate thetransmission area in the case of a simplified node distribution. Finally, we are interested on data collection mechanisms as they make inter-vehicle communications more efficient and reliable and minimize the bandwidth utilization. Our technique uses Q-learning to collect data among moving vehicles in VANETs. The aim behind using the learning technique is to make the collecting operation more reactive to nodes mobility and topology changes. For the simulation part, we compare it to a non-learning version to study the effect of the learning technique. Findings show that our technique far outperforms other propositions and achieves a good trade off between delay and collection ratio. In conclusion, we believe that the different contributions presented in this Thesis will improve the efficiency of inter-vehicle communications in both dissemination and data collection directions. In addition, our mathematical contributions will enrich the literature in terms of constructing suitable models to evaluate broadcasting techniques in urban zones

Les réseaux véhiculaires constituent une catégorie de réseaux sans fil mobiles à part entière et présentent l'originalité de permettre aux véhicules de communiquer les uns avec les autres mais aussi avec l'infrastructure quand elle existe. L'apparition des réseaux véhiculaires s'est accompagnée de l'apparition d'une myriade et variété d'applications potentielles allant de la sécurité à la gestion du trafic routier en passant par les applications de divertissement et de confort des usagers de la route. Ces applications ont suscité beaucoup d'intérêt de la part des chercheurs, des constructeurs des automobiles et des opérateurs des télécommunications. Les applications d'information et de divertissement, pour lesquelles une grande quantité de contenus peut exister, exigent que les contenus engendrés soient propagés au travers des véhicules et/ou de l'infrastructure jusqu'à atteindre les utilisateurs intéressés tout en respectant les durées de vie potentiellement limitées des contenus. La dissémination de contenus pour ce type d'applications reste un défi majeur en raison de plusieurs facteurs tels que la présence de beaucoup de contenus, la connectivité très intermittente mais encore les intérêts potentiellement hétérogènes des utilisateurs. C'est à cette thématique que nous sommes intéressés dans cette thèse; Tout d'abord, nous nous proposons une nouvelle métrique qui calcule l'utilité apportée aux utilisateurs. Elle permet de mesurer leur satisfaction par rapport aux contenus reçus. Nous la jugeons nécessaire pour évaluer les performances d'une approche de dissémination pour les applications de confort par opposition à des applications de sécurité routière. Dans un deuxième temps, nous nous concentrons sur le développement d'un nouveau protocole de dissémination, appelé I-PICK, et d'une solution de sélection des nœuds relais, appelé I-SEND, pour disséminer les contenus d'information et de divertissement en tenant compte des préférences des utilisateurs par rapport aux contenus reçus. Notre proposition est fondée sur l'échange de messages périodiques permettant l'estimation des durées de contacts et la connaissance des préférences des utilisateurs. Ces informations sont ensuite utilisées, dans un premier temps, pour effectuer un ordonnancement efficace des contenus lors de la dissémination puis choisir les relais permettant de maximiser l'utilité des utilisateurs par rapport aux contenus reçus dans un environnement caractérisé par des faibles durées de communication. Au travers de simulations nous confirmons l'efficacité de notre approche. Pour conforter le fonctionnement de nos mécanismes, nous avons implanté dans un environnement réel nos propositions I-PICK et I-SEND. Au travers d'un scénario simple, nous avons mis en évidence des risques liés à l'hétérogénéité des machines ou bien encore la difficulté du paramétrage des temporisations. Ces premiers résultats positifs montrent l'intérêt de notre technique et ouvre des pistes d'amélioration. Notre dernière contribution concerne des mécanismes de réduction du trafic cellulaire à l'aide des communications opportunistes entre les véhicules. Quand un contenu est disponible auprès d'un serveur de contenus accessible par le réseau cellulaire, il est nécessaire de proposer une méthode efficace de sélection des sources initiales qui seront choisies pour télécharger puis disséminer les contenus. Nous optons pour une solution qui pourrait reposer sur technologie SDN ainsi que sur des communications opportunistes et qui permet de choisir les sources en tant que nœuds pouvant produire un maximum d'utilité en propageant les contenus. / Vehicular networks are a class of mobile wireless networks and have the originality of enabling vehicles to communicate with each other and also with the infrastructure when it exists. The advent of vehicular networks has been accompanied by the emergence of a myriad and a variety of potential applications that are not only restricted to road safety but span from traffic management to entertainment and comfort applications. These applications have received much interest from researchers, automobile manufacturers, and telecommunications operators. Information and entertainment applications, where a large amount of content can exist, require the dissemination of the generated content through vehicles and/or infrastructure until reaching interested users while respecting the potential limited lifetime of content. The content dissemination for this type of applications remains a major challenge due to several factors such as the presence of a large amount of content, an intermittent connectivity, and the heterogeneous interests of users. In this thesis we turn our attention to this topic. First, we propose a new metric that allows to measure the users satisfaction with respect to the received content. This metric is used to evaluate the performance of the dissemination schemes. Second, we focus on the development of a new dissemination protocol, named I-PICK, and a forwarder selection solution, named I-SEND, to disseminate information and entertaining content in vehicular networks while ensuring maximum satisfaction of the users preferences with respect to the received content. Our proposal is based on the exchange of periodic messages enabling the estimation of contact durations and the knowledge of user preferences. First of all, this information is used to conduct an efficient content scheduling during the dissemination, and then to select relay nodes for maximizing the utility to users. We confirm the efficiency of our approach through simulations. To strengthen the functioning of our mechanisms, we implemented our proposals I-PICK and I-SEND in a real environment. Through a simple scenario, we have highlighted the risks associated with the heterogeneity of the machines and even the difficulty of setting timers. These first positive results show the interest of our solutions and raise new questions to be addressed. Our last contribution concerns cellular traffic offloading schemes by exploiting vehicular opportunistic communications. We study the seed-vehicles selection problem as the first step toward bootstrapping cellular traffic offloading for content dissemination in vehicular networks. We propose a solution that takes advantage from the presence of the SDN technology as well as vehicular opportunistic communications to select as seeds the nodes that can produce maximum utility when propagating the content.

Chaque jour, l'humanité perd des milliers de personnes sur les routes pendant qu'ils se rendaient à travailler, à étudier ou même à se distraire. Ce nombre alarmant s'accumule avec le coût financier terrifiant de ces décès: Certaines statistiques évaluent le coût à 160 milliards d'euros par an en Europe. Dans ce contexte, les réseaux véhiculaires (VANETs) émergent comme une technologie sans fil prometteuse capable d'améliorer la vision des conducteurs et ainsi offrir un horizon télématique plus vaste. Les applications de sécurité routière exigent que le message d'alerte soit propagé de proche en proche par les véhicules jusqu'à arriver à la zone concernée par l'alerte tout en respectant les délais minimaux exigés par ce type d'applications et la grande fiabilité des transmissions. Dans cette thèse, nous nous intéressons à l'amélioration de l'efficacité des communications inter-véhiculaires sous différents scénarios: tout d'abord, nous nous concentrons sur le développement d'une nouvelle solution, appelée EBDR, pour disséminer les informations d'alertes dans un réseau VANET tout en assurant des courts délais de bout en bout et une efficacité pour les transmissions. Notre proposition est basée sur des transmissions dirigées effectuées à l'aide des antennes directionnelles pour la diffusion des messages et un algorithme de guidage d'itinéraire afin de choisir le meilleur chemin pour le paquet. En dépit de son fonctionnement en diffusion, les transmissions de notre technique s'arrêtent très rapidement après l'arrivée du paquet à la destination finale ce qui représente une caractéristique fondamentale dans la conception d’EBDR. Deuxièmement, nous proposons un framework mathématique ayant pour objectif l'évaluation des performances d’EBDR analytiquement. Nos modèles analytiques permettent de dériver des métriques de performances significatives à savoir la probabilité de succès et le nombre de sauts requis pour atteindre la destination finale. En outre, nous proposons une amélioration de notre protocole EBDR dans le but de fournir une diffusion plus efficace. Pour cela, nous nous basons sur l'ajustement de la puissance de transmission de chaque véhicule en fonction de la distance qui le sépare de la destination et la densité locale des nœuds. Ce mécanisme de contrôle de congestion permet de mieux minimiser les interférences et économiser de la bande passante. En plus, un modèle mathématique a été élaboré pour calculer la surface de la zone de transmission dans le cas d'une distribution uniforme des nœuds. Finalement, nous nous sommes intéressés aux mécanismes de collecte de données dans les réseaux véhiculaires. Notre approche est basée sur l'utilisation du principe du Q-learning pour la collecte des données des véhicules en mouvement. L'objectif de l'utilisation de ce mécanisme d'apprentissage est de rendre l'opération de collecte mieux adaptée à la mobilité des nœuds et le changement rapide de la topologie du réseau. Notre technique a été comparée à des méthodes n'utilisant pas du "learning", afin d'étudier l'effet du mécanisme d'apprentissage. Les résultats ont montré que notre approche dépasse largement les autres propositions en terme de performances et réalise un bon compromis entre le taux de collecte et les délais de bout en bout. Pour conclure, nous pensons que nos différentes contributions présentées tout le long de cette thèse permettront d'améliorer l'efficacité des communications sans fil inter-véhiculaires dans les deux directions de recherches ciblées par cette thèse à savoir : la dissémination des messages et la collecte des données. En outre, nos contributions de modélisation mathématique enrichiront la littérature en termes de modèles analytiques capables d'évaluer les techniques de transmission des données dans un réseau véhiculaire / Each day, Humanity loses thousands of persons on roads when they were traveling to work, to study or even to distract. The financial cost of these injuries is also terrifying: Some statistics evaluate the financial cost of vehicle accidents at 160 billion Euro in Europe each year. These alarming figures have driven researchers, automotive companies and public governments to improve the safety of our transportation systems and communication technologies aiming at offering safer roads and smooth driving to human beings. In this context, Vehicular Adhoc Networks, where vehicles are able to communicate with each others and with existent road side units, emerge as a promising wireless technology able to enhance the vision of drivers and offer larger telematic horizon. VANETs promising applications are not only restricted to road safety but span from vehicle trafficoptimization like flow congestion control to commercial applications like file sharing and internet access. Safety applications require that their alert information is propagated to the concerned vehicles (located in the hazardous zone) with little delay and high reliability. For these reasons, this category of applications is considered as delay sensitive and broadcast-oriented nature. While classical blind flooding is rapid, its major drawback is its huge bandwidth utilization. In this thesis, we are interested on enhancing vehicular communications under different scenarios and optimizations: First, We focus on deriving a new solution (EBDR) to disseminate alert messages among moving vehicles while maintaining it efficient and rapid. Our proposal is based on directional antennas to broadcast messages and a route guidance algorithm to choose the best path for the packets. Findings confirmed the efficiency of our approach in terms of probability of success and end-to-end delays. Moreover, in spite of the broadcast nature of the proposed technique, all transmissions stop very soon after the arrival of a packet to its destination representing a strong feature in the conception of EBDR. Second, we propose a novel mathematical framework to evaluate the performance of EBDR analytically. Although most of the proposed techniques present in literature use experimental or simulation tools to defend their performance, we rely here on mathematical models to confirm our achieved results. Our proposed framework allows to derive meaningful performance metrics including the probability of transmission success and the required number of hops to reach thefinal destination. Third, we refine our proposed broadcast-based routing EBDR to provide more efficient broadcasting by adjusting the transmission range of each vehicle based on its distance to the destination and the local node density. This mechanism allows better minimization of interferences and bandwidth's saving. Furthermore, an analytical model is derived to calculate thetransmission area in the case of a simplified node distribution. Finally, we are interested on data collection mechanisms as they make inter-vehicle communications more efficient and reliable and minimize the bandwidth utilization. Our technique uses Q-learning to collect data among moving vehicles in VANETs. The aim behind using the learning technique is to make the collecting operation more reactive to nodes mobility and topology changes. For the simulation part, we compare it to a non-learning version to study the effect of the learning technique. Findings show that our technique far outperforms other propositions and achieves a good trade off between delay and collection ratio. In conclusion, we believe that the different contributions presented in this Thesis will improve the efficiency of inter-vehicle communications in both dissemination and data collection directions. In addition, our mathematical contributions will enrich the literature in terms of constructing suitable models to evaluate broadcasting techniques in urban zones