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Seppecher, Manon. "Mining call detail records to reconstruct global urban mobility patterns for large scale emissions calculation." Electronic Thesis or Diss., Lyon, 2022. http://www.theses.fr/2022LYSET002.
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En milieu urbain, le trafic routier contribue de manière significative aux émissions atmosphériques, enjeu majeur de la lutte contre le changement climatique. Par conséquent, la surveillance conjointe du trafic routier et des émissions qu’il génère constitue un support essentiel de la décision publique. Au-delà de simples procédures de suivi, les pouvoirs publics ont besoin de méthodes d’évaluation des politiques de transport selon des critères environnementaux.Le couplage de modèles de trafic avec des modèles d’émissions constitue une réponse adaptée à ce besoin. Cependant, l’intégration de tels models à des outils d'aide à la décision nécessite une ca-ractérisation fine et dynamique de la mobilité urbaine. Les données de téléphonie mobile, et en particulier les statistiques d'appel (données CDR), sont une alternative aux données traditionnelles pour estimer cette mobilité. Elles sont riches, massives, et disponibles partout dans le monde. Néanmoins, leur utilisation pour la caractérisation systématique du trafic routier est restée limitée. Cela s'explique par une faible résolution spatiale et des taux d'échantillonnage temporels sensible aux comportements de communication.Cette thèse de doctorat interroge l'estimation des variables de trafic nécessaires au calcul d'émis-sions atmosphériques (distances totales parcourues et vitesses moyennes de trafic) à partir de telles données, et malgré leurs biais. Une première contribution importante est d’articuler des méthodes de classification des individus avec deux approches distinctes de reconstruction de la mobilité. Un seconde contribution est le développement d'une méthode d'estimation des vitesses de trafic basée sur la fusion de larges quantité de données de déplacements. Enfin, un processus méthodologique complet de modélisation et de traitement des données est avancé. Il articule de façon cohérente les méthodes proposées dans cette thèseRoad traffic contributes significantly to atmospheric emissions in urban areas, a major issue in the fight against climate change. Therefore, joint monitoring of road traffic and related emissions is essential for urban public decision-making. And beyond this kind of procedure, public authorities need methods for evaluating transport policies according to environmental criteria.Coupling traffic models with traffic-related emission models is a suitable response to this need. However, integrating this solution into decision support tools requires a refined and dynamic char-acterization of urban mobility. Cell phone data, particularly Call Detail Records, are an interesting alternative to traditional data to estimate this mobility. They are rich, massive, and available worldwide. However, their use in literature for systematic traffic characterization has remained limited. It is due to low spatial resolution and temporal sampling rates sensitive to communication behaviors.This Ph.D. thesis investigates the estimation of traffic variables necessary for calculating air emis-sions (total distances traveled and average traffic speeds) from such data, despite their biases. The first significant contribution is to articulate methods of classification of individuals with two distinct approaches of mobility reconstruction. A second contribution is developing a method for estimating traffic speeds based on the fusion of large amounts of travel data. Finally, we present a complete methodological process of modeling and data processing. It relates the methods proposed in this thesis coherently
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Xu, Sanlin, and SanlinXu@yahoo com. "Mobility Metrics for Routing in MANETs." The Australian National University. Faculty of Engineering and Information Technology, 2007. http://thesis.anu.edu.au./public/adt-ANU20070621.212401.
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A Mobile Ad hoc Network (MANET) is a collection of wireless mobile nodes forming a temporary network without the need for base stations or any other preexisting network infrastructure. In a peer-to-peer fashion, mobile nodes can communicate with each other by using wireless multihop communication. Due to its low cost,
high flexibility, fast network establishment and self-reconfiguration, ad hoc networking has received much interest during the last ten years. However, without a fixed infrastructure, frequent path changes cause significant numbers of
routing packets to discover new paths, leading to increased network congestion and transmission latency over fixed networks. Many on-demand routing protocols have been developed by using various routing mobility metrics to choose the most reliable
routes, while dealing with the primary obstacle caused by node mobility.
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In the first part, we have developed an analysis framework for mobility metrics in random mobility model. Unlike previous research, where the mobility metrics were mostly studied by simulations, we derive the analytical expressions of mobility
metrics, including link persistence, link duration, link availability, link residual time, link change rate and their path equivalents. We also show relationships between the different
metrics, where they exist. Such exact expressions constitute precise mathematical relationships between network connectivity and node mobility.
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We further validate our analysis framework in Random Walk Mobility
model (RWMM). Regarding constant or random variable node velocity, we construct the transition matrix of Markov Chain Model through the analysis of the PDF of node separation after one epoch. In addition, we present intuitive and simple expressions for the link residual time and link duration, for the RWMM, which relate them directly to the ratio between transmission range and node speed. We also illustrate the relationship between link change rate and link duration. Finally, simulation results for all mentioned mobility metrics are reported which match well the proposed analytical framework.
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In the second part, we investigate the mobility metric applications on caching strategies and hierarchy routing algorithm. When on-demand routing employed, stale route cache
information and frequent new-route discovery in processes in MANETs generate considerable routing delay and overhead. This thesis proposes a practical route caching strategy to minimize routing delay and/or overhead by setting route cache timeout to a mobility metric, the expected path residual time. The strategy is independent of network traffic load and adapts to various
non-identical link duration distributions, so it is feasible to implement in a real-time route caching scheme. Calculated results
show that the routing delay achieved by the route caching scheme is only marginally more than the theoretically determined minimum. Simulation in NS-2 demonstrates that the end-to-end delay from DSR routing can be remarkably reduced by our caching scheme. By using overhead analysis model, we demonstrate that the minimum routing overhead can be achieved by increasing timeout to around twice the expected path residual time, without significant increase in routing delay.
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Apart from route cache, this thesis also addresses link cache strategy which has the potential to utilize route information more efficiently than a route cache scheme. Unlike some previous link cache schemes delete links at some fixed time after they enter the cache, we proposes using either the expected path duration or the link residual time as the link cache timeout. Simulation results in NS-2 show that both of the proposed link caching schemes can improve network performance in the DSR by reducing dropped data packets, latency and routing overhead, with the link residual time scheme out-performing the path duration scheme.
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To deal with large-scale MANETs, this thesis presents an adaptive k-hop clustering algorithm (AdpKHop), which selects clusterhead (CH) by our CH selection metrics. The proposed CH selection criteria enable that the chosen CHs are closer to the cluster centroid and more stable than other cluster members with respect to node mobility. By using merging threshold
which is based on the CH selection metric, 1-hop clusters can merge to k-hop clusters, where the size of each k-hop cluster adapts to the node mobility of the chosen CH. Moreover, we propose a routing overhead analysis model for k-hop clustering
algorithm, which is determined by a range of network parameters, such as link change rate (related to node mobility), node degree and cluster density. Through the overhead analysis, we show that an optimal k-hop cluster density does exist, which is
independent of node mobility. Therefore, the corresponding optimal
cluster merging threshold can be employed to efficiently organise k-hop clusters to achieve minimum routing overhead, which is highly desirable in large-scale networks.
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The work presented in this thesis provides a sound basis for future research on mobility analysis for mobile ad hoc networks, in aspects such as mobility metrics, caching strategies and k-hop clustering routing protocols.
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Nelson, Daniel B. "Internet-Scale Reactive Routing and Mobility." DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/100.
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Since its commercialization, the Internet has grown exponentially. A large variety of devices can communicate creating advanced services for a diverse ecosystem of applications. However, as the number of Internet hosts has grown, the size of routing tables required to correctly route data between them has also increased exponentially. This growth rate necessitates increasingly frequent upgrades to routing device hardware, providing them with additional memory for fast-access storage of route information. These upgrades are both physically and fiscally untenable, and a new Internet routing solution is necessary for future growth.
This research focuses around an incrementally deployable, reactive routing system that is scalable to projected Internet growth. It requires no hardware or software updates to Internet routers, and offoads processing to end hosts and the network's edge. Within this framework, routers can make accurate decisions about optimal data paths; incurring no increase in path length over the current routing system.
A new architecture for IP Mobility is considered as a case study within this routing system, and compared with existing standards and implementations. The new architecture eliminates the triangle routing problem, while providing legacy hosts with connectivity to mobile devices. This mobility solution can integrate with a variety of hierarchical reactive routing systems with little overhead.
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Xu, Sanlin. "Mobility metrics for routing in MANETs /." View thesis entry in Australian Digital Theses Program, 2007. http://thesis.anu.edu.au/public/adt-ANU20070621.212401/index.html.
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Moodie, Myron L., Maria S. Araujo, Todd A. Newton, Ben A. Abbott, and Thomas B. Grace. "Accomplishing Seamless IP Mobility in iNET Systems." International Foundation for Telemetering, 2011. http://hdl.handle.net/10150/595612.
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ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, NevadaOne of the core philosophies of the integrated Network Enhanced Telemetry (iNET) project is to leverage standard networking technologies whenever possible to both reduce development cost and to allow standard networking applications to function. This also provides the best long-term scalability to new unforeseen applications, much as the Internet has grown through its open standards. Unfortunately, the radio frequency (RF) channel characteristics do not fully lend themselves to the typical physical layer approaches utilized by IP technologies. As such, the iNET program has developed a specialized communication link management control. But, combining this specialized link management approach with the standardized IP infrastructure on the range and test article provides some challenges. The program has chosen a method to encapsulate the special concepts within a set of components that together (at their boundaries) form a classic router. Construction of this router is quite unique in that portions of it are geographically separate: antenna sites, test article, and mission control room. This paper describes the construction of what the program calls a "virtual router" and explains the performance issues that required it.
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Chama, Namusale Chibwe Maggie. "Impact of node mobility in user-centric routing." Doctoral thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/15783.
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Doutoramento em Engenharia Eletrotécnica -TelecomunicaçõesRecent paradigms in wireless communication architectures describe environments where nodes present a highly dynamic behavior (e.g., User Centric Networks). In such environments, routing is still performed based on the regular packet-switched behavior of store-and-forward. Albeit sufficient to compute at least an adequate path between a source and a destination, such routing behavior cannot adequately sustain the highly nomadic lifestyle that Internet users are today experiencing. This thesis aims to analyse the impact of the nodes’ mobility on routing scenarios. It also aims at the development of forwarding concepts that help in message forwarding across graphs where nodes exhibit human mobility patterns, as is the case of most of the user-centric wireless networks today. The first part of the work involved the analysis of the mobility impact on routing, and we found that node mobility significance can affect routing performance, and it depends on the link length, distance, and mobility patterns of nodes. The study of current mobility parameters showed that they capture mobility partially. The routing protocol robustness to node mobility depends on the routing metric sensitivity to node mobility. As such, mobility-aware routing metrics were devised to increase routing robustness to node mobility. Two categories of routing metrics proposed are the time-based and spatial correlation-based. For the validation of the metrics, several mobility models were used, which include the ones that mimic human mobility patterns. The metrics were implemented using the Network Simulator tool using two widely used multi-hop routing protocols of Optimized Link State Routing (OLSR) and Ad hoc On Demand Distance Vector (AODV). Using the proposed metrics, we reduced the path re-computation frequency compared to the benchmark metric. This means that more stable nodes were used to route data. The time-based routing metrics generally performed well across the different node mobility scenarios used. We also noted a variation on the performance of the metrics, including the benchmark metric, under different mobility models, due to the differences in the node mobility governing rules of the models.
Os paradigmas recentes de arquiteturas de comunicação sem fios consistem em ambientes onde os dispositivos apresentam um comportamento dinâmico (e.g., Redes Centradas no Utilizador). Nestes ambientes, o encaminhamento de dados ainda é realizado com base no comportamento de armazenamento e encaminhamento da comutação clássica de pacotes. Embora seja suficiente para calcular, pelo menos, um caminho adequado entre uma origem e um destino, tal comportamento de encaminhamento não é adequado nas redes móveis e sem fios atuais. Esta tese tem como objetivo analisar o impacto da mobilidade dos utilizadores sobre os diferentes cenários de encaminhamento. A tese também visa o desenvolvimento de conceitos de encaminhamento que ajudam na distribuição de dados através de grafos, nos quais os vértices exibem padrões de mobilidade humana, como é o caso hoje em dia para a maior parte das redes sem fios centradas no utilizador. A primeira parte desta tese envolveu a análise do impacto da mobilidade dos utilizadores no encaminhamento, com a análise de que a mobilidade, para afetar o desempenho do encaminhamento, depende do comprimento do caminho entre a origem e o destino, da distância entre os dispositivos, e dos diferentes padrões de mobilidade. O estudo dos atuais parâmetros de mobilidade mostrou que eles capturam parcialmente a mobilidade dos utilizadores. A robustez dos protocolos de encaminhamento depende da sensibilidade das métricas no que concerne a esta mobilidade. Assim, foram concebidas métricas de encaminhamento baseadas na mobilidade dos utilizadores para aumentar a robustez do encaminhamento em relação à mobilidade. As duas categorias de métricas de encaminhamento criadas foram métricas que têm como base o tempo e a correlação espacial. Para a validação das métricas foram utilizados vários modelos de mobilidade, incluindo os modelos que imitam padrões de mobilidade humana. As métricas foram implementadas utilizando a ferramenta Network Simulator e considerando dois protocolos de encaminhamento por múltiplos saltos amplamente utilizados, o Optimized Link State Routing (OLSR) e o Adhoc On Demand Distance Vector (AODV). Com a utilização das métricas propostas observa-se que a frequência de realização de novos cálculos de caminhos de comunicação foi reduzida em relação à métrica de referência. Isto significa que foram usados caminhos mais estáveis para encaminhar dados. As métricas de encaminhamento baseadas no tempo apresentam geralmente um bom desempenho nos diferentes cenários de mobilidade utilizados. Observou-se também uma variação no desempenho das métricas, incluindo a métrica de referência, nos diferentes modelos de mobilidade considerados, devido a diferenças nas regras de mobilidade dos utilizadores dos diferentes modelos.
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Ben, Jemaa Inès. "Communication multicast pour les systèmes véhiculaires coopératifs." Thesis, Paris, ENMP, 2014. http://www.theses.fr/2014ENMP0065/document.
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La communication véhiculaire permet le développement de nouvelles applications multicast émergentes telles que la gestion de la flotte et la distribution des Points d'Intérêt (POI). Ces deux catégories d'applications nécessitent une communication multicast de l'Internet vers les réseaux véhiculaires (VANET). Afin de mettre en place une communication multicast adaptée au contexte de la communication Internet-vers-réseaux véhiculaires, notre travail traite de deux aspects différents. Tout d'abord, l'accessibilité des véhicules en mouvement au service Internet et en deuxième lieu, la dissémination du message dans les VANET. Nous introduisons un schéma d'adressage multicast basé sur les coordonnées géographiques des véhicules qui leur permet de s'auto-configurer d'une façon dynamique sans aucun besoin d'échanger des messages de signalisation avec Internet. Nous proposons aussi une approche simplifiée de gestion de la mobilité des véhicules dans le cadre des architectures Mobile IP et Proxy Mobile IP. Le but de cette approche est d'optimiser l'échange des messages avec les entités responsables de la gestion de la mobilité dans Internet. Afin d'étudier les mécanismes de dissémination appropriés aux applications de gestion de flottes, nous nous proposons de revisiter les techniques de routage multicast traditionnelles basées sur une structure de diffusion en arbre. Pour cela, nous étudions leur application aux réseaux véhiculaires. Nous présentons une étude théorique portant sur la durée de vie des liens entre les véhicules en milieux urbains. Ensuite, en utilisant la simulation, nous étudions l'application de Multicast Adhoc On Demand Vector, MAODV et proposons Motion-MAODV, une version adaptée de MAODV qui a pour objectif d'établir des routes plus robustes Enfin, concernat la dissémination multicast géolocalisée dans les applications POI, nous proposons le protocole de routage Melody qui permet une diffusion geocast en milieu urbain. A partir de simulations, nous constatons que, comparé aux protocoles de géo-brodcasting dans les milieux urbain très denses, Melody assure plus de fiabilité et d'efficacité lors de l'acheminement des données vers les zones géographiques de destinationVehicular communications allow emerging new multicast applications such as fleet management and point of interest (POI). Both applications require Internet-to-vehicle multicasting. These approaches could not be applied to vehicular networks (VANET) due to their dynamic and distributed nature. In order to enable such multicasting, our work deals with two aspects. First, reachability of the moving vehicles to the multicast service and second, multicast message dissemination in VANET. We introduce first a self-configuring multicast addressing scheme that allows the vehicles to auto-configure a dynamic multicast address without a need to exchange signalling messages with the Internet. Second, we propose a simplified approach that extends Mobile IP and Proxy Mobile IP. This approach aims at optimizing message exchange between vehicles and entities responsible for managing their mobility in Internet. To study the dissemination mechanisms that are suitable for fleet management applications, we propose to revisit traditional multicast routing techniques that rely on a tree structure. For this purpose, we study their application to vehicular networks. In particular, as vehicular networks are known to have changing topology, we present a theoretical study of the link lifetime between vehicles in urban environments. Then, using simulations, we study the application of Multicast Adhoc On Demand Vector, MAODV. We propose then Motion-MAODV, an improved version of MAODV that aims at enhancing routes built by MAODV in vehicular networks and guarantee longer route lifetime. Finally, to enable geographic dissemination as required by POI applications, we propose a routing protocol Melody that provides a geocast dissemination in urban environments. Through simulations, Melody ensures more reliable and efficient packet delivery to a given geographic area compared to traditional geo-brodcasting schemes in highly dense scenarios
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Saint-Guillain, Michael. "Models and algorithms for online stochastic vehicle routing problems." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI068.
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Quels seront les objectifs et défis des métropoles de demain ? La plupart des problèmes issus du monde réel sont sujets à l'inconnu, nécessitant de prendre de nouvelles décisions de façon dynamique, à la demande, en fonction des évènements aléatoires qui se réalisent. Dans cette thèse, nous nous attaquons à un problème majeur, du moins en perspectives: la gestion dynamique d'une flotte de véhicules en contexte urbain. Les applications pratiques des tournées de véhicules à la demande sont nombreuses, incluant les transports publics intelligents, les services de livraison, les soins et interventions à domicile, etc. Étant donnés une flotte de véhicules et un ensemble de clients, chacun pouvant potentiellement et à tout moment émettre une requête nécessitant une intervention, l'objectif de cette thèse est de fournir une réponse à la question suivante. Étant donné l'état courant à un moment donné, comment gérer notre flotte de véhicules afin de maximiser l'espérance du nombre total de requêtes satisfaites à la fin de la journée ? Ou encore, comment minimiser l'espérance du délai moyen d'intervention de nos véhicules ? Bien entendu, la difficulté réside en ce que la plupart des requêtes, avant d'apparaître dynamiquement, ne sont pas connues. Pour chaque problème, nous considérons qu'il nous est fourni une connaissance, sous forme d'information probabiliste, telle que la probabilité qu'une requête apparaisse à un certain endroit, et à un certain moment de la journée. Grâce à des techniques issues de la recherche opérationnelle et de la programmation stochastique, nous sommes en mesure de construire et résoudre des modèles calculant les actions anticipatives les plus adéquates, comme le redéploiement préventif des véhicules, minimisant le coût total espéré, ou encore maximisant la qualité de service. La question de l'optimisation sous incertitude se pose depuis déjà plusieurs décennies. Grâce aux avancées à la fois théoriques et technologiques, nous sommes chaque jour un peu plus en mesure de palier à l'inconnu. Cependant, la plupart des problèmes intéressants restent extrêmement difficiles à résoudre, si ce n'est impossible. Il reste beaucoup à faire. Cette thèse explore certains concepts fondamentaux de l'optimisation sous incertitude. En intégrant une composante stochastique aux modèles à optimiser, nous verrons ensemble comment il est en effet possible de créer de l'anticipationWhat will be tomorrow's big cities objectives and challenges? Most of the operational problems from the real world are inherently subject to uncertainty, requiring the decision system to compute new decisions dynamically, as random events occur. In this thesis, we aim at tackling an important growing problem in urban context: online dynamic vehicle routing. Applications of online vehicle routing in the society are manyfold, from intelligent on demand public transportation to sameday delivery services and responsive home healthcare. Given a fleet of vehicles and a set of customers, each being potentially able to request a service at any moment, the current thesis aims at answering the following question. Provided the current state at some moment of the day, which are the best vehicle actions such that the expected number of satisfied requests is maximized by the end of the operational day? How can we minimize the expected average intervention delays of our mobile units? Naturally, most of the requests remain unknown until they appear, hence being revealed online. We assume a stochastic knowledge on each operational problem we tackle, such as the probability that customer request arise at a given location and a given time of the day. By using techniques from operations research and stochastic programming, we are able to build and solve mathematical models that compute near-optimal anticipative actions, such as preventive vehicle relocations, in order to either minimize the overall expected costs or maximize the quality of service. Optimization under uncertainty is definitely not a recent issue. Thanks to evolution of both theoretical and technological tools, our ability to face the unknown constantly grows. However, most of the interesting problems remain extremely hard, if not impossible, to solve. There is still a lot of work. Generally speaking, this thesis explores some fundamentals of optimization under uncertainty. By integrating a stochastic component into the models to be optimized, we will see how it is in fact possible to create anticipation
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Cho, Gi Hwan. "Location and routing optimization protocols supporting internet host mobility." Thesis, University of Newcastle Upon Tyne, 1996. http://hdl.handle.net/10443/2105.
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With the popularity of portable computers and the proliferation of wireless networking interfaces, there is currently a great deal of interest in providing IP networking support for host mobility using the Internet as a foundation for wireless networking. Most proposed solutions depend on a default route through the mobile host's horne address, which makes for unnecessarily long routes. The major problem that this gives rise to is that of finding an efficient way of locating and routing that allows datagrams to be delivered efficiently to moving destinations whilst limiting costly Internet-wide location updates as much as possible. Two concepts - "local region" and "patron service" - are introduced based on the locality features of the host movement and packet traffic patterns. For each mobile host, the local region is a set of designated subnetworks within which a mobile host often moves, and the patrons are the hosts from which the majority of traffic for the mobile host originated. By making use of the hierarchical addressing and routing structure of Internet, the two concepts are used to confine the effects of a host moving, so location updates are sent only to a designated host moving area and to those hosts which are most likely to call again, thus providing nearly optimal routing for most communication. The proposed scheme was implemented as an IP extension using a network simulator and evaluated from a system performance point of view. The results show a significant reduction in the accumulated communication time along with improved datagram tunneling, as compared with its extra location overhead. In addition, a comparison with another scheme shows that our functionality is more effective both for location update and routing efficiency. The scheme offers improved network and host scalability by isolating local movement from the rest of the world, and provides a convenient point at which to perform administration functions.
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Alchaita, Mohammed Husein. "Routing and mobility strategies for mobile ad hoc networks." Thesis, De Montfort University, 2006. http://hdl.handle.net/2086/4289.
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Samal, Savyasachi. "Mobility Pattern Aware Routing in Mobile Ad Hoc Networks." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/34984.
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A mobile ad hoc network is a collection of wireless nodes, all of which may be mobile, that dynamically create a wireless network amongst them without using any infrastructure. Ad hoc wireless networks come into being solely by peer-to-peer interactions among their constituent mobile nodes, and it is only such interactions that are used to provide the necessary control and administrative functions supporting such networks. Mobile hosts are no longer just end systems; each node must be able to function as a router as well to relay packets generated by other nodes. As the nodes move in and out of range with respect to other nodes, including those that are operating as routers, the resulting topology changes must somehow be communicated to all other nodes as appropriate. In accommodating the communication needs of the user applications, the limited bandwidth of wireless channels and their generally hostile transmission characteristics impose additional constraints on how much administrative and control information may be exchanged, and how often. Ensuring effective routing is one of the greatest challenges for ad hoc networking.
As a practice, ad hoc routing protocols make routing decisions based on individual node mobility even for applications such as disaster recovery, battlefield combat, conference room interactions, and collaborative computing etc. that are shown to follow a pattern.
In this thesis we propose an algorithm that performs routing based on underlying mobility patterns. A mobility pattern aware routing algorithm is shown to have several distinct advantages such as: a more precise view of the entire network topology as the nodes move; a more precise view of the location of the individual nodes; ability to predict with reasonably accuracy the future locations of nodes; ability to switch over to an alternate route before a link is disrupted due to node movements.Master of Science
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Tudorache, Ion Gabriel. "Peripheral Routing Protocol : a new routing protocol proposal for a realistic WSN mobility model." Thesis, University of Leeds, 2014. http://etheses.whiterose.ac.uk/7871/.
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Wireless sensor networks (WSNs) are changing our way of life just as the internet has revolutionized the way people communicate with each other. Future wireless networks are envisioned to be robust, have simple and efficient communication between nodes and self-organizing dynamic capabilities. When new nodes join in, a self-configuring network has to have the ability to include these nodes in its structure in real time, without human or machine interference. The need for a destination node (D) which moves at the periphery of wireless sensor networks can be argued from different points of view: the first is that different WSN scenarios require data gathering in such a way; the second point is that this type of node movement maximizes network lifetime because it offers path diversity preventing the case where the same routes are used excessively. However the peripheral movement model of the mobile destination does not resemble any mobility models presented in the WSN literature. In this thesis a new realistic WSN sink mobility model entitled the “Marginal Mobility Model” (MMM) is proposed. This was introduced for the case when the dynamic destination (D), moving at the periphery, frequently exits and enters the WSN coverage area. We proved through Qualnet simulations that current routing protocols recommended for Mobile Ad Hoc Networks (MANETs) do not support this sink mobility model. Because of this, a new routing protocol is proposed to support it called the Peripheral Routing Protocol (PRP). It will be proven through MATLAB simulations that, for a military application scenario where D’s connectivity to the WSN varies between 10%-95%, compared with the 100% case, PRP outperforms routing protocols recommended for MANETs in terms of throughput (T), average end to end delay (AETED) and energy per transmitted packet (E). Also a comparison will be made between PRP and Location-Aided Routing (LAR) performance when D follows the MMM. Analytical models for both PRP and LAR are proposed for T and E. It is proved through MATLAB simulations that, when compared with LAR, PRP obtains better results for the following scenarios: when the WSN size in length and width is increased to 8000 m and one packet is on the fly between sender and sink, PRP sends 103% more data and uses 84% less energy; when more data packets are on the fly between sender and sink, PRP sends with 99.6% more data packets and uses 81% less energy; when the WSN density is increased to 10,000 nodes PRP uses 97.5% less energy; when D’s speed in increased to 50 Km/h, PRP sends 74.7% more data packets and uses 88.4% less energy.
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Li, Chen. "Automatic extraction of behavioral patterns for elderly mobility and daily routine analysis." HKBU Institutional Repository, 2018. https://repository.hkbu.edu.hk/etd_oa/510.
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The elderly living in smart homes can have their daily movement recorded and analyzed. Given the fact that different elders can have their own living habits, a methodology that can automatically identify their daily activities and discover their daily routines will be useful for better elderly care and support. In this thesis research, we focus on developing data mining algorithms for automatic detection of behavioral patterns from the trajectory data of an individual for activity identification, daily routine discovery, and activity prediction. The key challenges for the human activity analysis include the need to consider longer-range dependency of the sensor triggering events for activity modeling and to capture the spatio-temporal variations of the behavioral patterns exhibited by human. We propose to represent the trajectory data using a behavior-aware flow graph which is a probabilistic finite state automaton with its nodes and edges attributed with some local behavior-aware features. Subflows can then be extracted from the flow graph using the kernel k-means as the underlying behavioral patterns for activity identification. Given the identified activities, we propose a novel nominal matrix factorization method under a Bayesian framework with Lasso to extract highly interpretable daily routines. To better take care of the variations of activity durations within each daily routine, we further extend the Bayesian framework with a Markov jump process as the prior to incorporate the shift-invariant property into the model. For empirical evaluation, the proposed methodologies have been compared with a number of existing activity identification and daily routine discovery methods based on both synthetic and publicly available real smart home data sets with promising results obtained. In the thesis, we also illustrate how the proposed unsupervised methodology could be used to support exploratory behavior analysis for elderly care.
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Mehar, Sara. "The vehicle as a source and consumer of information : collection, dissemination and data processing for sustainable mobility." Thesis, Dijon, 2014. http://www.theses.fr/2014DIJOS069/document.
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Aujourd'hui, les véhicules sont devenus de plus en plus sophistiqués, intelligents et connectés. En effet, ils sont équipés de capteurs, radars, GPS, interfaces de communication et capacités de traitement et de stockage élevés. Ils peuvent collecter, traiter et communiquer les informations relatives à leurs conditions de travail et leur environnement formant un réseau véhiculaire. L'intégration des technologies de communication sur les véhicules fait l'objet d'une immense attention de l'industrie, des autorités gouvernementales et des organisations de standardisations; elle a ouvert la voie à des applications innovantes qui vont révolutionner le marché de l'automobile avec les principaux objectifs d'assurer la sécurité sur les routes, augmenter l'efficacité des transports et offrir un confort aux conducteurs et passagers. En outre, le transport est un secteur en évolution active. Des moyens de transport plus durables comme les véhicules électriques s'introduisent progressivement sur le marché de l'automobile tout en créant de nouveaux défis liés à la contrainte énergétique et la protection de l'environnement qui restent à résoudre.De nombreux projets et études ont été initiés exploitant les avantages des technologies de l'information et de communication (TIC) afin de répondre aux différents défis des systèmes de transport. Cependant, avoir des véhicules connectés et coopératifs crée un réseau hautement dynamique caractérisé par des ruptures de lien et de pertes de messages très fréquentes. Pour résoudre ces problèmes de communication, cette thèse se concentre sur deux axes majeurs: (i) le véhicule connecté (ou mobilité connectée) et (ii) la mobilité durable. Dans la première partie de cette thèse, la diffusion, la collecte et l'acheminement de données dans un réseau de véhicule sont adressés. Ainsi, un nouveau protocole de diffusion est proposé afin de faire face à la fragmentation et la connectivité intermittente dans ces réseaux. Ensuite, une nouvelle stratégie de déploiement d'infrastructure de communication est conçue afin d'améliorer la connectivité réseau et l'utilisation des ressources. Enfin, un nouveau protocole de routage, pour applications sensibles au délai, utilisant cette nouvelle infrastructure de communication est proposé. La deuxième partie se concentre sur la mobilité durable avec un focus sur les véhicules électriques et avec un objectif de réduire les problèmes de pollution et d'utiliser efficacement l'énergie. Une nouvelle architecture de gestion de flottes de véhicules électriques est proposée. Cette dernière utilise les protocoles implémentés dans la première partie de cette thèse afin de collecter, traiter et diffuser les données. Elle permet de surmonter les limitations liées à la courte autonomie des batteries des véhicules électriques. Ensuite, pour répondre aux besoins et défis d'équilibre énergétique, un nouveau schéma de déploiement des stations de recharge pour véhicules électriques est proposé. Cette solution permet de satisfaire les demandes des conducteurs en terme d'énergie, tout en tenant compte les capacités énergétiques disponiblesToday, vehicles have become more sophisticated, intelligent and connected. Indeed, they are equipped with sensors, radars, GPS, communication interfaces and high processing and storage capacities. They can collect, process and communicate information related to their working conditions and their environment forming a vehicular network. The incorporation of communication technologies on vehicles garnered a huge attention of industry, government authorities and standardizations organizations and opened the way for innovative applications that revolutionized the automotive market with the main goals to ensure safety on roads, increase transport efficiency and provide comfort to drivers and passengers. In addition, transportation is still an actively evolving sector. More sustainable means of transportation such as electric vehicles are introduced progressively to the automotive market with new challenges related to energy consumption and environment preservation that remain to be solved. Many research investigations and industrial projects are done to exploit the advantages of information and communication technologies (ICT) to fit with transportation challenges. However, having connected and cooperative vehicles creates a highly dynamic network characterized by frequent link breaks and message losses. To cope with these communication limitations, this thesis focuses on two major axis: (i) connected vehicle or connected mobility and (ii) sustainable mobility. In the first part of this thesis, data dissemination, collection and routing in vehicular networks are addressed. Thus, a new dissemination protocol is proposed to deal with frequent network fragmentation and intermittent connectivity in these networks. Then, a new deployment strategy of new communication infrastructure is developed in order to increase network connectivity and enhance the utilization of the network resources. Finally, a new routing protocol, for delay-sensitive applications, that uses the optimized infrastructure deployment is proposed. The second part focuses on sustainable mobility with a focus on electric vehicles and with the main objective is to reduce pollution issues and make better use of energy. A new architecture for electric vehicles fleet management is proposed. This latter uses the implemented protocols of the first part of this thesis in order to collect, process and disseminate data. It helps to overcome the limitations related to short autonomy of electric vehicles. Then, to meet energy balance challenges, a new deployment scheme for electric vehicles charging stations is developed. This solution helps to satisfy drivers’ demands in term of energy while taking into account available resources
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Pholpabu, Pitiphol. "Human mobility models and routing protocols for mobile social networks." Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/419474/.
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In mobile social networks (MSNs), there are a number of challenges to face, which include the design of well-performed routing protocols. Since performance evaluation of a routing protocol in real world is costly and time consuming, it is usually more practical to evaluate the performance relying on the syn-thetic data generated by simulations. Accordingly, a number of mobility models have been proposed to provide the real-trace-like scenarios that can be used in development and performance evaluation of routing protocols. In this thesis, we concern the problem of dynamic routing in MSNs. First, two mobility models are proposed, which are the Preferred-Community-Aware Mobility (PCAM) and Role Playing Mobility (RPM) models. While designed based on thesimplicity and randomness of the Random WayPoint (RWP) mobility model, the PCAM model enhances it by exploiting the fact that people often have their favorite places to visit, resulting in the so-called human social behavior of mutual preferred communities. On the other hand, the RPM model further improves the PCAM model by jointly considering people’s behaviour of mutual-preferred- communities and their daily schedules. Then, based on the mobility models proposed, we design some routing protocols and investigate the effect of human social behavior on the routing performance in MSNs. Firstly, a Social Contact Probability assisted Routing (SCPR) protocol is proposed, which is capable of exploiting the properties of encounters between mobile nodes (MNs) and the relationship strength between MNs and communities. Secondly, considering that the energy-efficiency issues have not been addressed in the existing routing protocols for MSNs, we propose two types of energy-concerned routing protocols, which are the Energy-Concerned Routing (EnCoR) and Energy-efficient Social Distance Routing (ESDR) protocols. It can be shown that these two types of routing protocols are capable of achieving the trade-off among Energy Consumption (EC), Delivery Ratio (DR), and Delay (D), shortened as the EC/DR/D trade-off. Specifically, the EnCoR protocol controls the EC/DR/D trade-off by a threshold introduced to the route selection process, while the ESDR protocol achieves the EC/DR/D trade-off by taking into account of the length of messages and the estimation of the number of hops. Furthermore, we show that, by invoking our EnCoR or ESDR scheme, most existing routing protocols can be readily extended to their corresponding versions that are flexible to achieve the EC/DR/D trade-off. In this thesis, the performance of the proposed routing protocols are investigated with the aid of simulations, which are compared with a range of existing routing protocols for MSNs. Our studies and performance results show that the proposed protocols are capable of efficiently integrating the merits of high delivery ratio, low delivery latency and low resource consumption of the existing protocols, while simultaneously circumventing their respective shortcomings. Our proposed protocols are capable of attaining a good trade-off among the delivery ratio, average delivery delay, and the cost of resources (including energy) for operation of the protocols.
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Mucelli, Rezende Oliveira Eduardo. "From Human Routine to More Efficient Mobile Networks." Palaiseau, Ecole polytechnique, 2015. https://theses.hal.science/tel-01160280/document.
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L’omniprésence des communications a entraîné une récente augmentation des volumes de données mobiles, pour laquelle les opérateurs n’étaient pas toujours préparés. Les smartphones sont les plus gros consommateurs de données mobiles. Ces appareils peuvent être considérés comme méchants à cause d’un tel traffic, mais d’un point de vue analytique ils fournissent, aujourd’hui un des meilleurs moyens afin de collecter les données sur le comportement de consommation et de mobilité de grande échelle. Comprendre le comportement des utilisateurs sur leur mobilité et leur connectivité est nécessaire à la création d’un système de communication effectifs. Nous sommes routiniers. Ces cycles routiniers sont une grande partie de nos interactions avec le monde. Par exemple, nos habitudes definissent ce que l’on va faire le samedi ou les sites que nous consultons le lundi matin. Ces comportements répétés reflètent nos déplacements et activités en ligne. Dans cette thèse, nous allons nous concentrer sur les demandes de traffic générées par les usagers métropolitains durant leurs activités quotidiennes. Nous présentons une étude détaillée des usagers selon les comportements routiniers de mobilité ou d’activité sur internet. Dans une étude de cas, ou cette enquête serait utile, nous proposons une stratégies de déploiement de points de accès qui prendra en compte les aspects routiniers de la mobilités des utilisateurs. Nous étudirons en premier lieu, les modèles de mobilité en milieu urbain. Nous analyserons les données de mobilité à grande échelle dans de grandes villes comme Beijing, Tokyo, New York, Paris, San Francisco, London, Moscow, Mexico City. Cette contribution se fait en deux étapes. Premièrement, nous observerons les similitudes des déplacements peu importe la ville concernée. Ensuite, nous mettrons en évidence trois caractéristiques présentes dans les déplacements d’une population urbaine typique: Répétivité, utilisation de raccourcis, confinement. Ces caractéristiques sont dues à la tendance qu’ont les personnes à revisiter les même rues en utilisant les trajectoires proches du chemin le plus court. D’ailleurs, les personnes ont une mobilité quotidienne inférieure à dix kilomètres par jour. Nous avons ensuite étudié les modèles de demandes de traffic en utilisant une base de données comprenant les données de 6. 8 millions d’utilisateurs. Pour cela nous avons principalement deux contributions. Premièrement, une caractérisation précise des comportements de consommation des utilisateurs agrégés par modèle. Nous pouvons voir comment les routines quotidiennes impactent nos demandes de connections et la similarité de ce traffic en fonction des jours. En suite, nous fournirons un moyen de reproduire artificiellement mais avec cohérence les modèles des utilisateurs de données mobiles. Ces données synthétisées ont l’avantage de permettre la planification du réseau sans information sur la vie privées de utilisateurs comme les bases de données d’origine. Afin d’évaluer l’efficacité de ces informations dans un scénario grandeur nature, nous proposerons une stratégie de deploiement de points de accès qui prend en compte les caractéristiques routinières en terme de déplacement et de demande de trafic dans le but d’améliorer la décharge de données mobile. Déployer correctement des points de accès WiFi peut être moins cher que d’améliorer l’infrastructure de réseaux mobiles, et peut permettre d’améliorer considérablement la capacité du réseau. Notre approche améliore l’évacuation de trafic comparée aux autres solutions disponibles dans la littératureThe proliferation of pervasive communication caused a recent boost up on the mobile data usage, which network operators are not always prepared for. The main origin of the mobile network demands are smartphone devices. From the network side those devices may be seen as villains for imposing an enormous traffic, but from the analytical point of view they provide today the best means of gathering users information about content consumption and mobility behavior on a large scale. Understanding users' mobility and network behavior is essential in the design of efficient communication systems. We are routinary beings. The routine cycles on our daily lives are an essential part of our interface with the world. Our habits define, for instance, where we are going Saturday night, or what is the typical website for the mornings of Monday. The repetitive behavior reflects on our mobility patterns and network activities. In this thesis we focus on metropolitan users generating traffic demands during their normal daily lives. We present a detailed study on both users' routinary mobility and routinary network behavior. As a study of case where such investigation can be useful, we propose a hotspot deployment strategy that takes into account the routine aspects of people's mobility. We first investigate urban mobility patterns. We analyze large-scale datasets of mobility in different cities of the world, namely Beijing, Tokyo, New York, Paris, San Francisco, London, Moscow and Mexico City. Our contribution is this area is two-fold. First, we show that there is a similarity on people's mobility behavior regardless the city. Second, we unveil three characteristics present on the mobility of typical urban population: repetitiveness, usage of shortest-paths, and confinement. Those characteristics undercover people's tendency to revisit a small portion of favorite venues using trajectories that are close to the shortest-path. Furthermore, people generally have their mobility restrict to a dozen of kilometers per day. We then investigate the users' traffic demands patterns. We analyze a large data set with 6. 8 million subscribers. We have mainly two contributions in this aspect. First, a precise characterization of individual subscribers' traffic behavior clustered by their usage patterns. We see how the daily routine impacts on the network demands and the strong similarity between traffic on different days. Second, we provide a way for synthetically, still consistently, reproducing usage patterns of mobile subscribers. Synthetic traces offer positive implications for network planning and carry no privacy issues to subscribers as the original datasets. To assess the effectiveness of these findings on real-life scenario, we propose a hotspot deployment strategy that considers routine characteristics of mobility and traffic in order to improve mobile data offloading. Carefully deploying Wi-Fi hotspots can both be cheaper than upgrade the current cellular network structure and can concede significant improvement in the network capacity. Our approach increases the amount of offload when compared to other solution from the literature
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Desmouceaux, Yoann. "Network-Layer Protocols for Data Center Scalability." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLX011/document.
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Du fait de la croissance de la demande en ressources de calcul, les architectures de centres de données gagnent en taille et complexité.Dès lors, cette thèse prend du recul par rapport aux architectures réseaux traditionnelles, et montre que fournir des primitives génériques directement à la couche réseau permet d'améliorer l'utilisation des ressources, et de diminuer le trafic réseau et le surcoût administratif.Deux architectures réseaux récentes, Segment Routing (SR) et Bit-Indexed Explicit Replication (BIER), sont utilisées pour construire et analyser des protocoles de couche réseau, afin de fournir trois primitives: (1) mobilité des tâches, (2) distribution fiable de contenu, et (3) équilibre de charge.Premièrement, pour la mobilité des tâches, SR est utilisé pour fournir un service de migration de machine virtuelles sans perte.Cela ouvre l'opportunité d'étudier comment orchestrer le placement et la migration de tâches afin de (i) maximiser le débit inter-tâches, tout en (ii) maximisant le nombre de nouvelles tâches placées, mais (iii) minimisant le nombre de tâches migrées.Deuxièmement, pour la distribution fiable de contenu, BIER est utilisé pour fournir un protocole de multicast fiable, dans lequel les retransmissions de paquets perdus sont ciblés vers l'ensemble précis de destinations n'ayant pas reçu ce packet : ainsi, le surcoût de trafic est minimisé.Pour diminuer la charge sur la source, cette approche est étendue en rendant possible des retransmissions par des pairs locaux, utilisant SR afin de trouver un pair capable de retransmettre.Troisièmement, pour l'équilibre de charge, SR est utilisé pour distribuer des requêtes à travers plusieurs applications candidates, chacune prenant une décision locale pour accepter ou non ces requêtes, fournissant ainsi une meilleure équité de répartition comparé aux approches centralisées.La faisabilité d'une implémentation matérielle de cette approche est étudiée, et une solution (utilisant des canaux cachés pour transporter de façon invisible de l'information vers l'équilibreur) est implémentée pour une carte réseau programmable de dernière génération.Finalement, la possibilité de fournir de l'équilibrage automatique comme service réseau est étudiée : en faisant passer (avec SR) des requêtes à travers une chaîne fixée d'applications, l'équilibrage est initié par la dernière instance, selon son état localWith the development of demand for computing resources, data center architectures are growing both in scale and in complexity.In this context, this thesis takes a step back as compared to traditional network approaches, and shows that providing generic primitives directly within the network layer is a great way to improve efficiency of resource usage, and decrease network traffic and management overhead.Using recently-introduced network architectures, Segment Routing (SR) and Bit-Indexed Explicit Replication (BIER), network layer protocols are designed and analyzed to provide three high-level functions: (1) task mobility, (2) reliable content distribution and (3) load-balancing.First, task mobility is achieved by using SR to provide a zero-loss virtual machine migration service.This then opens the opportunity for studying how to orchestrate task placement and migration while aiming at (i) maximizing the inter-task throughput, while (ii) maximizing the number of newly-placed tasks, but (iii) minimizing the number of tasks to be migrated.Second, reliable content distribution is achieved by using BIER to provide a reliable multicast protocol, in which retransmissions of lost packets are targeted towards the precise set of destinations having missed that packet, thus incurring a minimal traffic overhead.To decrease the load on the source link, this is then extended to enable retransmissions by local peers from the same group, with SR as a helper to find a suitable retransmission candidate.Third, load-balancing is achieved by way of using SR to distribute queries through several application candidates, each of which taking local decisions as to whether to accept those, thus achieving better fairness as compared to centralized approaches.The feasibility of hardware implementation of this approach is investigated, and a solution using covert channels to transparently convey information to the load-balancer is implemented for a state-of-the-art programmable network card.Finally, the possibility of providing autoscaling as a network service is investigated: by letting queries go through a fixed chain of applications using SR, autoscaling is triggered by the last instance, depending on its local state
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Gikaru, Wilfred Githuka. "Mobility based routing overhead management in reconfigurable wireless ad hoc networks." Doctoral thesis, [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=97340423X.
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Ksouri, Chahrazed. "Smart Mobility and Routing in Intermittent Infrastructure-based Internet of Vehicles." Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0286.
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De grands progrès ont été réalisés dans le domaine des transports, ce qui a conduit à l'émergence du concept de la Smart Mobility. Dans cette thèse, nous nous intéressons à l'aspect technologique du concept. Nous proposons une vision plus large de la Smart Mobility, tout en spécifiant trois domaines de mobilité; à savoir terrestre, aérien et marin. Nous nous concentrons ensuite sur le domaine terrestre, plus précisément, les protocoles de routage dans l'Internet des véhicules (IoV). Dans l'environnement véhiculaire, trois catégories de scénario de réseau doivent être distinguées: infrastructure basée, sans infrastructure et infrastructure intermittente. Dans ce travail, nous souhaitons permettre aux véhicules d'atteindre l'infrastructure en temps opportun dans le troisième scénario. À cette fin, nous proposons ILTS (Infrastructure Localization Service and Tracking Scheme) qui extrait des informations précieuses de l'échange de messages périodiques afin de localiser l'infrastructure et de suivre les chemins disponibles vers elle. Ensuite, nous proposons un protocole de routage basé sur un mécanisme de prise de décision, HyRSIC (Hybrid Routing for Safety data with Intermittent V2I Connectivity), qui permet aux véhicules de faire le choix optimal lors de la transmission des donnéesGreat progress has been made in the transportation field, which has led to the emergence of the Smart Mobility concept. In this thesis, we are interested in the technological aspect of the concept. We propose a broader vision of Smart Mobility, while specifying three mobility domains; namely terrestrial, aerial and marine. We then, focus on the terrestrial domain, more precisely, routing protocols in Internet of Vehicles (IoV). In the vehicular environment, three categories of network scenario are to be distinguished: infrastructure-based, infrastructure-less and intermittent infrastructure. In this work, we are interested in enabling vehicles to reach the infrastructure in a timely manner in the third scenario. To this end, we propose ILTS (Infrastructure Localization service and Tracking Scheme) that extracts valuable information from periodic message exchange in order to localize infrastructure and track available paths towards it. Then, we propose a routing protocol based on a decision making mechanism, HyRSIC (Hybrid Routing for Safety data with Intermittent V2I Connectivity), that enables vehicles to make the optimal choice when transmitting data
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Chitedze, Zimani. "Mobility management for Wi-Fi infrastructure and mesh networks." University of the Western Cape, 2012. http://hdl.handle.net/11394/2960.
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Magister Scientiae - MScThis thesis shows that mobility management protocols for infrastructure Internet may be used in a wireless mesh network environment. In this research Mobile IPv6 and Fast Handover for Hierarchical Mobile IPv6 are successfully implemented in a wireless mesh network environment. Two experiments were carried out: vertical and horizontal handover simulations. Vertical handover simulation involved a heterogeneous wireless environment comprising both wireless local area and wireless mesh networks. An OPNET Mobile IPv6 model was used to simulate the vertical handover experiment. Horizontal handover simulation involved Mobile IPv6 and Fast Handover for Hierarchical Mobile IPv6 applied in ns2 wireless mesh network. The vertical handover results show that MIPv6 is able to manage vertical handover between wireless local area and wireless mesh network. The horizontal handover results illustrate that in mesh networks, Fast Handover for Hierarchical Mobile IPv6's performance is superior to Mobile IPv6. Fast Handover for Hierarchical Mobile IPv6 generates more throughput and less delay than Mobile IPv6. Furthermore, Fast Handover for Hierarchical Mobile IPv6 drops less data packets than Mobile IPv6. The simulations indicate that even though there are multi-hop communications in wireless mesh networks, the performance of the multi-hop routing may not play a big role in the handover performance. This is so because the mesh routers are mostly static and the multi-hop routes are readily available. Thus, the total handover delay is not affected too much by the WMN hops in the paths for signaling message transmission.
South Africa
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Ouattara, Yacouba. "Gestion de l'énergie et de la connectivité dans les réseaux de capteurs sans fil statiques et mobiles." Thesis, Besançon, 2015. http://www.theses.fr/2015BESA2046/document.
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Un certain nombre de travaux basés sur les réseaux de capteurs sans fil s'intéressent à la gestion de l'énergie de ces capteurs. Cette énergie est, de fait, un facteur critique dans le fonctionnement de ces réseaux. Une construction adéquate des clusters de capteurs est un très bon moyen pour minimiser la consommation de cette énergie. La problématique liée à ces réseaux réside ainsi souvent dans leur durée de vie mais aussi dans le nécessaire maintien de la connectivité entre tous les capteurs. Ces deux aspects sont étroitement liés. Dans cette thèse, nous nous sommes focalisés sur ces deux volets, dans le contexte de réseaux de capteurs statiques mais aussi celui de capteurs mobiles.Nous proposons, dans un premier temps, un algorithme hybride pour la mise en place des clusters et la gestions de ces clusters. L'originalité de cette solution réside dans la mise en place de zones géographiques de désignation des cluster heads mais aussi dans la transmission, dans les messages échangés, de la quantité d'énergie restante sur les capteurs. Ainsi, les données sur les capteurs permettront de désigner les cluster heads et leurs successeurs qui détermineront les seuils pour les autres capteurs et pour leur fonctionnement. L'algorithme est testé à travers de nombreuses simulations. La seconde partie du travail consiste à adapter notre premier algorithme pour les réseaux de capteurs mobiles. Nous in_uons sur la trajectoire des capteurs pour maintenir la connectivité et limiter la consommation d'énergie. Pour cela, nous nous inspirons de l'écho-localisation pratiquée par les chauvessouris. Nous nous sommes donc intéressés à la topologie changeante et dynamique dans les réseaux de capteurs. Nous avons analysé la perte d'énergie en fonction de la distance et de la puissance de transmission entre les n÷uds et le cluster head. Nous évaluons également notre algorithme sur des capteurs qui ont un déplacement aléatoire. Nous appliquons ces algorithmes à une simulation de _otte de drones de surveillanceA number of works based on wireless sensor networks are interested in the energy management of these sensors. This energy is in fact a critical factor in the operation of these networks. Proper construction of sensor clusters is a great way to minimize the consumption of this energy. The problems related to these networks and often lies in their lifetime but also in the need to maintain connectivity between all transducers. These two aspects are closely linked. In this thesis, we focused on these two aspects in the context of static sensor networks but also of mobile sensors.We propose, as a _rst step, a hybrid algorithm for setting up clusters and the management of theseclusters. The uniqueness of this solution lies in the establishment of geographic areas for designation fcluster heads but also in transmission, in the exchanged messages, the amount of remaining energy on the sensors. Thus, the sensor data will designate the cluster heads and their successors will determine the thresholds for other sensors and for their operation. The algorithm is tested through many simulations. The second part of the work is to adapt our _rst algorithm for mobile sensor networks. We a_ect the trajectory of sensors to maintain connectivity and reduce energy consumption. For this, we are guided echo-location practiced by bats. We're interested in changing and dynamic topology in sensor networks. We analyzed the loss of energy as a function of the distance and the power transmission between the nodes and the head cluster. We also evaluate our algorithm on sensors that have a random move. We apply these algorithms to a _eet of surveillance drones simulation
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Bindel, Sébastien. "Algorithmique et applications pour les flottes hétérogènes multiniveaux de matériels mobiles communicants autonomes." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0172/document.
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Les véhicules autonomes sont des engins mobiles caractérisés par l’absence de pilote à leur bord et font partie d’un système plus global comprenant des éléments tels qu’une station de contrôle. Ils présentent la particularité d’avoir une conception spécifique liée à la mission assignée et peuvent être déployés dans des milieux divers et hétérogènes, incluant le milieu spatial, aérien,terrestre, marin de surface et sous-marin.Certaines missions requièrent la coopération de véhicules hétérogènes, où chaque type de véhicule réalise une mission locale pour permettre la réalisation d’une mission globale. La coopération entre les véhicules nécessite l’interopérabilité des communications. Même si des efforts ont été entrepris dans ce sens en normalisant les couches applicatives, ces travaux restent insuffisants.En effet, il n’existe pas de protocole qui assure l’acheminement des données entre différents types de véhicules qui possèdent une mobilité propre et utilisent parfois des médias de communication différents, comme les engins sous-marins et terrestres. L’objectif principal de cette thèse est de permettre à tous les engins de communiquer entre eux et de rendre cette interconnexion transparente. Pour cela, nous adoptons une approche multicouche qui nous permet de diffuser et d’acheminer des données vers n’importe quel engin. Il devient alors possible pour chaque véhicule de transmettre des données de manière transparente à un autre véhicule de nature différente sans connaître la topologie globale du réseau. Pour cela nous avons conçu un protocole de routage qui adapte sa politique en fonction du contexte et de l’environnement.Nous exploitons également un mode de diffusion qui permet de transmettre des données vers un engin faisant partie d’un groupe cible en nous basant sur leurs caractéristiques afin d’acheminer les données de manière optimaleUnmanned vehicles are defined as autonomous entities with no operator on board. They are a part of a global system called Unmanned System which also includes elements such as a control station. These vehicles are designed to fulfil the requirements of assigned missions and can be deployed in spatial, aerial, terrestrial and maritime environments. Since a mission cannot be accomplished with a single vehicle, vehicles have to cooperate in order to achieve a global mission. However, cooperation requires communication interoperability between all vehicles. Even if previous works have standardized application protocols, it is not sufficient to ensure data delivery between all vehicles, since they have a specific mobility pattern and sometimes different network interfaces. The main goal of this thesis is to offer a seamless network, including all kinds of unmanned systems. We propose a cross layer approach in order to route and deliver data to any vehicle. In this context, each vehicle is able to transmit data to another without information on the global topology. We have developed a routing protocol, which adapts its strategy, according to the contextand to the network environment. In addition, we exploit the any cast diffusion technique based on vehicles features in order to adopt an optimal routing scheme
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Brunisholz, Pierre. "Supports de communications ubiquitaires pour les réseaux à l'échelle de la ville." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAM033/document.
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Le Wi-Fi est omniprésent dans les villes, que ce soit par le nombre grandissant de point d'accès public, ou la déploiement massif de points d'accès privés, sous la forme de boxes d'opérateurs notamment. Si nous supposons que l'ensemble de ces points d'accès soient utilisables afin de permettre à n'importe quel appareil d'accéder à Internet, alors nous aurions potentiellement une couverture réseau sur l'ensemble de la ville. Ce postulat nous a conduit à nous demander si le Wi-Fi pouvait être utilisé comme réseau à l'échelle urbaine. Ce réseau pourrait plus particulièrement être utilisé dans un contexte de mobilité. Or, le Wi-Fi n'a pas été conçu dans le but de gérer des utilisateurs mobiles,et les appareils doivent régulièrement changer de points d'accès lorsqu'ils n'ont plus de connectivité. Ce mécanisme, appelé handover, peut être long car les appareils doivent d'abord constater leurs pertes de connectivité avant de commencer à chercher le prochain point d'accès auquel s'associer. Il peut être particulièrement long pour des appareils comme les smartphones car ces derniers sont contraint en énergie et n'appliquent donc pas une politique de handover aggressive. Dans ce contexte nous avons cherché à caractériser les applications possible sur le Wi-Fi lorsqu'un utilisateur est mobile, en fonction de la durée de handover de son équipement, de sa vitesse et de la densité des points d'accès présents dans la ville. Nous avons constaté que pour les utilisateurs se déplaçant à faible allure, l'impact de la durée de handover est faible au regard de la connectivité totale, ce qui leur permet d'utiliser des applications gourmandes en terme de bande passante tant que celles-ci possèdent un certain degré de tolérances aux déconnexions. Cependant lorsque la vitesse de déplacement augmente, la durée de handover dégrade progressivement la connectivité des utilisateurs, de telle sorte que ceux ayant une allure élevée ne peuvent plus espérer utiliser les différents points d'accès. En effet, les équipements passent alors plus de temps à effectuer des handovers qu'à échanger des données applicatives. Les retransmissions jouant un rôle important dans la durée de handover, nous avons étudié finement leurs fonctionnement en 802.11.Pour cela nous avons mis en place un banc d'essai nous permettant d'observer les séquences de messages retransmis par différentes implémentations de 802.11lorsque l'on fait subitement disparaitre le point d'accès. Nous avons comparé ces séquences avec celle décrite dans le standard, et nous avons constaté que le nombre de retransmissions maximal ainsi que l'augmentation de la fenêtre de contention n'étaient pas respectés. De plus, ces implémentations passent beaucoup de temps à tenter de retransmettre avant d'initier leurs procédures de handover. Les retransmissions sont aussi utilisées dans les algorithmes d'adaptation de débits afin de déterminer si le lien se dégrade. Or, lors de la contention, le nombres de pertes augmente avec la plus forte probabilité de collisions. Afin d'observer l'impact des retransmissions sur les algorithmes d'adaptation de débits lors de la contention, nous avons mis en place un banc d'essai composé d'une trentaine de stations identiques. Nous avons constaté que l'algorithme de contrôle de débit utilisé est sous optimal par rapport à l'utilisation d'une modulation unique. Enfin, nous nous sommes intéressés à l'utilisation d'un tel réseau à l'échelle de la ville afin d'acheminer des données ayant une forte validité spatiale. Nous avons alors proposé un schéma d'adressage géographique exploitant l'infrastructure d'Internet. Il permet à la fois d'obtenir un découpage hiérarchique du monde, et d'avoir un préfixe hiérarchique des adresses, similaire à celui de CIDR. Nous montrons que ce schéma d’adressage peut être utilisé dans des adresses multicast pour envoyer des messages à destination de zones géographiques précises (surface minimale d'un mètre carré)Wi-Fi is everywhere in cities, whether through the growing number of publicaccess points, or the massive private access points deployment, in the formof set-top boxes for the major part.If we assume that all these access points are usable in order to allow anydevice to access the Internet, then we would potentially have network coveragethroughout the city.This assumption led us to wonder if Wi-Fi could be used as a city-wide network.This network could, more specifically, be used in a context of mobility.However, Wi-Fi was not designed to manage mobile users, and devices have tooften change their access points when they no longer have connectivity.This mechanism, called handover, can be long because devices must first detecttheir connectivity losses before they can start looking for the next accesspoint to associate with.It can be particularly long for devices such as smartphones because they areenergy constrained and therefore do not apply an aggressive handover policy.In this context we tried to characterize the possible Wi-FI applications for amoving user, considering the handover duration, the user speed and the accesspoints density in the city.We found that for slow-moving users, the impact of the handover is smallcompared to the their overall connectivity.This allows them to use bandwidth-intensive applications as long as they areto some extend delay-tolerant.However, when the user’s speed increases, the impact of handover’s durationgradually degrades the user’s connectivity, so that high speed users can nolonger expect to use different access points.Fast moving devices spend more time performing handovers with new access pointsthan transmitting application data.Retransmissions play an important role in the duration of handover.In order to study in detail the retransmissions in 802.11, we have set up atestbed allowing us to observe the sequences of retransmitted messages usingdifferent implementations of 802.11 when we suddenly make the access pointdisappear.We compared these sequences with the one described in the standard, and we wefound that the maximum number of retransmissions as well as the growth in thecontention window were not respected.In addition, these implementations spend a lot of time trying to retransmitbefore initiating their handover procedures.Retransmissions are also used in the rate control algorithms to determine ifthe link is deteriorating.However, during contention, the number of losses increases with the higherprobability of collisions.In order to observe the impact of retransmissions on the rate controlalgorithms during contention, we have set up a testbed composed of about thirtyidentical stations.We found that the rate control algorithm used underperforms compared to theuse of a single modulation.Finally, we proposed a geographical addressing scheme compliant with theInternet infrastructure.It allows to obtain both a hierarchical division of the world, and ahierarchical prefix for the addresses, similar to the one used in the CIDRformat.We show that this addressing scheme can be used in multicast addresses to sendmessages to specific geographical areas (minimum area of one square meter)
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Kuiper, Erik. "Mobility and Routing in a Delay-tolerant Network of Unmanned Aerial Vehicles." Licentiate thesis, Linköping University, Linköping University, RTSLAB - Real-Time Systems Laboratory, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-11430.
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Technology has reached a point where it has become feasible to develop unmanned aerial vehicles (UAVs), that is aircraft without a human pilot on board. Given that future UAVs can be autonomous and cheap, applications of swarming UAVs are possible. In this thesis we have studied a reconnaissance application using swarming UAVs and how these UAVs can communicate the reconnaissance data. To guide the UAVs in their reconnaissance mission we have proposed a pheromone based mobility model that in a distributed manner guides the UAVs to areas not recently visited. Each UAV has a local pheromone map that it updates based on its reconnaissance scans. The information in the local map is regularly shared with a UAV’s neighbors. Evaluations have shown that the pheromone logic is very good at guiding the UAVs in their cooperative reconnaissance mission in a distributed manner.
Analyzing the connectivity of the UAVs we found that they were heavily partitioned which meant that contemporaneous communication paths generally were not possible to establish. This means that traditional mobile ad hoc network (MANET) routing protocols like AODV, DSR and GPSR will generally fail. By using node mobility and the store-carry-forward principle of delay-tolerant routing the transfer of messages between nodes is still possible. In this thesis we propose location aware routing for delay-tolerant networks (LAROD). LAROD is a beacon-less geographical routing protocol for intermittently connected mobile ad hoc networks. Using static destinations we have shown by a comparative study that LAROD has almost as good delivery rate as an epidemic routing scheme, but at a substantially lower overhead.
Report code: LiU-Tek-Lic-2008:14
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Ramakrishnan, Karthik. "An Improved Model for the Dynamic Routing Effect Algorithm for Mobility Protocol." Thesis, University of Waterloo, 2005. http://hdl.handle.net/10012/864.
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An ad-hoc network is a packet radio network in which individual mobile nodes perform routing functions. Typically, an ad-hoc networking concept allows users wanting to communicate with each other while forming a temporary network, without any form of centralized administration. Each node participating in the network performs both the host and router function, and willing to forward packets for other nodes. For this purpose a routing protocol is needed. A novel approach utilizes the uniqueness of such a network i. e. distance, location and speed of the nodes, introducing a Distance Routing Effect Algorithm for Mobility (DREAM). The protocol uses the distance effect and the mobility rate as a means to assure routing accuracy. When data needs to be exchanged between two nodes, the directional algorithm sends messages in the recorded direction of the destination node, guaranteeing the delivery by following the direction. The improved algorithm suggested within this thesis project includes an additional parameter, direction of travel, as a means of determining the location of a destination node. When data needs to be exchanged between two nodes, the directional algorithm sends messages in the recorded direction of the destination node, guaranteeing the delivery by following the direction. The end result is an enhancement to the delivery ratio, of the sent to the received packet. This also allows the reduction in the number of control packets that need to be distributed, reducing the overall control overhead of the Improved Dream protocol.
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Amjad, Kashif. "The performance of MANET routing protocols with different mobility and propagation models." Thesis, University of Leicester, 2013. http://hdl.handle.net/2381/27910.
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Simulation tools are primary means for evaluating and analysing performance of Mobile Adhoc NETworks (MANETS). Different mobility and propagation models have been used in this context. However, simple propagation models have been used heavily in simulation based MANETS routing performance analysis. A range of propagation models (such as ITU-R P.1411-5, ITU-R P1238-6, GOA-LoS, modified TRG, C-Shadowing and WINNER) for various indoor/outdoor and LoS/NLoS scenarios have been added into ns-2 based simulation and results have been analysed with those readily available in the simulator for AODV, DSR and OLSR routing protocols. A variety of synthetic mobility models have been implemented under those pathloss conditions and their impact on routing performance has been observed. Heterogeneous mobility conditions have been introduced for performance analysis of AODV and DSR routing protocols under, TRG, ITU and GOA pathloss conditions. It has been found that the DSR protocol fails to perform where AODV prevails in specific mobility environment. RPGM model have been analysed with variations of mobility model adopted by group-heads and its impact on MANETS have been investigated. A very large adhoc network has been tested through ns-2 simulator with comparison of ITU and TRG channel loss conditions and its results have been compared with other scalable routing performance analysis studies. Impact of corner-loss effects due to typical street movement scenario such as under MG mobility have been experimented through ITU-R based recommendations in ns-2 simulation environment. A small testbed based AODV performance analysis has been compared with ns-2 based simulation results under ITU and Shadowing propagation models and significant difference have been recorded in real vs simulation based results for NRL and Mean. Delay analysis. In summary, MANET performance have been analysed under a range of operational conditions and applications and it has been demonstrated that various factors such as mobility and propagation environment could significantly challenge the deployment of such networks.
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Nguyen, Anh-Dung. "Contributions to modeling, structural analysis, and routing performance in dynamic networks." Phd thesis, Toulouse, INPT, 2013. http://oatao.univ-toulouse.fr/9725/1/nguyen.pdf.
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This thesis contributes to the modeling, understanding and efficient communication in dynamic networks populating the periphery of the Internet. By dynamic networks, we refer to networks that can be modeled by dynamic graphs in which nodes and links change temporally. In the first part of the thesis, we propose a new mobility model - STEPS - which captures a wide spectrum of human mobility behavior. STEPS implements two fundamental principles of human mobility: preferential attachment and attractor. We show that this simple parametric model is able to capture the salient statistical properties of human mobility such as the distribution of inter-contact/contact time. In the second part, using STEPS, we analyze the fundamental behavioral and structural properties of opportunistic networks. We redefine in the context of dynamic networks the concept of small world structure and show how such a structure can emerge. In particular, we show that highly dynamic nodes can play the role of bridges between disconnected components, helping to significantly reduce the length of network path and contribute to the emergence of small-world phenomenon in dynamic networks. We propose a way to model this phenomenon in STEPS. From a regular dynamic network in which nodes limit their mobility to their respective preferential areas. We rewire this network by gradually injecting highly nomadic nodes moving between different areas. We show that when the ratio of such nomadic nodes is around 10%, the network has small world structure with a high degree of clustering and a low characteristic path length. The third contribution of this thesis is the study of the impact of disorder and contact irregularity on the communication capacity of a dynamic network. We analyze the degree of disorder of real opportunistic networks and show that if used correctly, it can significantly improve routing performances. We then introduce a model to capture the degree of disorder in a dynamic network. We propose two simple and efficient algorithms that exploit the temporal structure of a dynamic network to deliver messages with a good tradeoff between resource usage and performance. The simulation and analytical results show that this type of algorithm is more efficient than conventional approaches. We also highlight also the network structure for which this type of algorithm achieves its optimum performance. Based on this theoretical result, we propose a new efficient routing protocol for content centric opportunistic networks. In this protocol, nodes maintain, through their opportunistic contacts, an utility function that summarizes their spatio-temporal proximity to other nodes. As a result, routing in this context consists in following the steepest slopes of the gradient field leading to the destination node. This property leads to a simple and effective algorithm routing that can be used both in the context of IP networks and content centric networks. The simulation results show that this protocol outperforms traditional routing protocols already defined for opportunistic networks. The last contribution of this thesis is to highlight the potential application of dynamic networks in the context of "mobile cloud computing." Using the particle optimization techniques, we show that mobility can significantly increase the processing capacity of dynamic networks. In addition, we show that the dynamic structure of the network has a strong impact on its processing capacity.
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Lundmark, Erik. "The Mobility of People, Ideas and Knowledge in the Entrepreneurial Society." Doctoral thesis, Linköpings universitet, Projekt, innovationer och entreprenörskap, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-63570.
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As radical innovations facilitate communication, create new industries and make others obsolete, the established ways of organising society are being questioned. Over the last few decades, a theoretical framework and a worldview labelled the entrepreneurial society, has emerged. The entrepreneurial society is based on theoretical models, empirical observations and a belief in the importance of new businesses. The core of the entrepreneurial society is the claim that valuable ideas have to be commercialised in order to contribute to economic growth and prosperity. Unfortunately, valuable ideas remain dormant due to a number of barriers. Labour mobility, informal networks and entrepreneurship are mechanisms with the potential of overcoming these barriers. This thesis aims to increase our understanding of how ideas diffuse between and get applied within organisations. The thesis relates its findings to the entrepreneurial society and identifies and critically assesses basic assumptions and biases underlying the framework. The thesis presents and discusses six studies, each published as an article in a scientific journal, a chapter in an edited book, or as a conference paper at an international academic conference. Taken together, the findings in this thesis emphasise that the mobility of ideas is intertwined with the mobility of people and knowledge. More specifically, the findings indicate that employees in large R&Ddriven projects not only attain knowledge from external sources, but also that the use of external knowledge sources is positively related to new ideas connected to the projects. In addition, this thesis reinforces the argument that the mobility of knowledge workers is particularly beneficial to the diffusion of knowledge and ideas between organisations; the results show that employees in knowledge-intensive positions perceive greater opportunities to generate, share and develop ideas in organisations, as compared to employees in less knowledge-intensive positions. This thesis suggests that new employees tend to have an entrepreneurial potential in the form of a greater drive for change and less habituation with current practices. Nevertheless, such potential is often curbed by resistant routines. However, the thesis also finds that much entrepreneurship literature and the discourse of policy makers are biased towards overly optimistic views of entrepreneurship. The literature on the entrepreneurial society emphasises the diffusion and application of new R&D-related knowledge and ideas. This thesis also emphasises the diffusion and application of already widespread and established knowledge, ideas and innovations.I takt med att radikala innovationer underlättar kommunikation, skapar nya branscher och gör andra obsoleta, ifrågasätts etablerade sätt att organisera samhället. De senaste årtiondena har ett teoretiskt ramverk och en världsåskådning, under benämningen det entreprenöriella samhället, vuxit fram. Det entreprenöriella samhället baseras på teoretiska modeller, empiriska observationer och en tro på vikten av nya företag. Kärnan i det entreprenöriella samhället är tesen att värdefulla idéer måste kommersialiseras för att bidra till ekonomisk tillväxt och välstånd. Olyckligtvis förblir många idéer outnyttjade på grund av en mängd barriärer. Arbetskraftsrörlighet, informella nätverk och entreprenörskap är mekanismer med potential att övervinna dessa barriärer. Syftet med denna avhandling är att öka vår förståelse av hur idéer sprids mellan, och tillämpas inom, organisationer. Avhandlingen relaterar resultaten till det entreprenöriella samhället, samt identifierar och granskar ramverkets underliggande antaganden och blinda fläckar. Avhandlingen presenterar och diskuterar sex studier, var och en publicerad som en artikel i en vetenskaplig tidskrift, som ett kapitel i en akademisk antologi eller som ett bidrag till en internationell vetenskaplig konferens. Sammantaget understryker resultaten i avhandlingen att idéers rörlighet är sammanvävd med människors och kunskaps rörlighet. Resultaten tyder på att anställda i stora FoU-drivna projekt inte bara inhämtar kunskap från externa källor utan också att dessa källor är relaterade till nya idéer och lösningar på problem i projekten. Vidare förstärker resultaten tidigare forskning som hävdar att organisationsbyten bland människor med kunskapsintensiva arbeten särskilt bidrar till att idéer och kunskap sprids mellan organisationer; resultaten visar att anställda med kunskapsintensiva arbeten upplever större möjligheter att generera, föreslå och utveckla idéer jämfört med anställda i mindre kunskapsintensiva positioner. Avhandlingens resultat indikerar också att nyanställda har en större entreprenöriell potential än mer etablerade anställda. Detta för att nyanställda har en större förändringsbenägenhet och att de ännu inte är inskolade i etablerade arbetssätt. Denna potential hålls emellertid ofta tillbaka av motståndskraftiga organisatoriska rutiner. Dessutom hävdar avhandlingen att mycket av entreprenörskapslitteraturen och den politiska diskursen uppvisar en överoptimistisk syn på entreprenörskap. Litteraturen bakom det entreprenöriella samhället betonar spridningen och tillämpningen av forskningsnära kunskap. Denna avhandling betonar även vidare spridning av redan spridd och etablerad kunskap, samt redan spridda och etablerade idéer och innovationer.
The authors Licentiate thesis "Organisational adoption of innovations : management practices and IT" is a part of this dissertation.
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Nirkhiwale, Supriya. "Optimal mobility patterns in epidemic networks." Thesis, Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/1494.
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Imadali, Sofiane. "Large scale addressing and routing mechanisms for highly mobile networks of networks." Thesis, Paris 11, 2015. http://www.theses.fr/2015PA112049/document.
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Cette thèse a pour objectif de faire avancer l'état de l'art des communications basée sur Internet Protocol version 6 (IPv6) dans le domaine des réseaux véhiculaires, et ce dans le cadre des évolutions récentes de IP, notamment l'avènement du Future Internet. Le Future Internet (F.I.) définit un ensemble d'approches pour faire évoluer l'Internet actuel , en particulier l'émergence d'un Internet mobile exigeant en ressources. Les acteurs de ce domaine définissent les contraintes inhérentes aux approches utilisées historiquement dans l'évolution de l'architecture d'Internet et tentent d'y remédier soit de manière évolutive soit par une rupture technologique (révolutionnaire). Un des problèmes au centre de cette nouvelle évolution d'Internet est la question du nommage et de l'adressage dans le réseau. Nous avons entrepris dans cette thèse l'étude de ce problème, dans le cadre restreint des communications véhiculaires Internet.Dans ce contexte, l'état de l'art du Future Internet a mis en avant les distinctions des approches révolutionnaires comparées aux propositions évolutives basées sur IPv6. Les réseaux véhiculaires étant d'ores-et-déjà dotés de piles protocolaires comprenant une extension IPv6, nous avons entamé une approche évolutive visant à intégrer les réseaux véhiculaires au Future Internet. Une première proposition a été de convertir un identifiant présent dans le monde automobile (VIN, Numéro d'Identification de Véhicule) en un lot d'adresses réseau propres à chaque véhicule (qui est donc propriétaire de son adressage issu de son identifiant). Cette proposition étant centrée sur le véhicule, nous avons ensuite intégré ces communications basés dans une architecture globale Future Internet basée sur IPv6 (protocole LISP). En particulier, et avec l'adressage VIN, nous avons défini un espace d'adressage indépendant des fournisseurs d'accès à Internet où le constructeur automobile devient acteur économique fournissant des services IPv6 à sa flotte de véhicules conjointement avec les opérateurs réseau dont il dépend pour transporter son trafic IP. Nous nous sommes ensuite intéressés à l'entourage proche du véhicule afin de définir un nouveau mode de communication inter-véhiculaire à Internet: le V2V2I (Angl. Vehicle-to-Vehicle-to-Infrastructure). Jusqu'à présent, les modes de transmission de données à Internet dans le monde du véhicule consistaient en des topologies V2I, à savoir véhicule à Internet, où le véhicule accède à l'infrastructure directement sans intermédiaire. Dans le cadre des communications véhiculaires à Internet, nous proposons une taxonomie des méthodes existantes dans l'état de l'art. Les techniques du Future Internet étant récentes, nous avons étendu notre taxonomie par une nouvelle approche basée sur la séparation de l'adressage topologique dans le cluster de celui de l'infrastructure. Le leader du cluster s'occupe d'affecter les adresses (de son VIN) et de gérer le routage à l'intérieur de son cluster. La dernière contribution consiste en la comparaison des performances des protocoles de gestion de mobilité, notamment pour les réseaux de véhicules et des communications de type vehicule-à-Internet. Dans ce cadre, nous avons proposé une classification des protocoles de gestion de mobilité selon leur déploiement: centralisé (basé réseau ou host) et distribué. Nous avons ensuite évalué les performances en modélisant les durées de configurations et de reconfigurations des différents protocoles concernésAfter successfully connecting machines and people later (world wide web), the new era of In-ternet is about connecting things. Due to increasing demands in terms of addresses, mobility, scalability, security and other new unattended challenges, the evolution of current Internet archi-tecture is subject to major debate worldwide. The Internet Architecture Board (IAB) workshop on Routing and Addressing report described the serious scalability problems faced by large backbone operators in terms of routing and addressing, illustrated by the unsustainable growth of the Default Free Zone (DFZ) routing tables. Some proposals tackled the scalability and IP semantics overload issues with two different approaches: evolutionary approach (backward com-patibility) or a revolutionary approach. Several design objectives (technical or high-level) guided researchers in their proposals. Mobility is definitely one of the main challenges.Inter-Vehicle Communication (IVC) attracts considerable attention from the research com-munity and the industry for its potential in providing Intelligent Transportation Systems (ITS) and passengers services. Vehicular Ad-Hoc Networks (VANETs) are emerging as a class of wire-less network, formed between moving vehicles equipped with wireless interfaces (cellular and WiFi) employing heterogeneous communication systems. A VANET is a form of mobile ad-hoc network that provides IVC among nearby vehicles and may involve the use of a nearby fixed equipment on the roadside. The impact of Internet-based vehicular services (infotainment) are quickly developing. Some of these applications, driver assistance services or traffic reports, have been there for a while. But market-enabling applications may also be an argument in favor of a more convenient journey. Such use cases are viewed as a motivation to further adoption of the ITS standards developed within IEEE, ETSI, and ISO.This thesis focuses on applying Future Internet paradigm to vehicle-to-Internet communica-tions in an attempt to define the solution space of Future Vehicular Internet. We first introduce two possible vehicle-to-Internet use cases and great enablers for IP based services : eHealth and Fully-electric Vehicles. We show how to integrate those use cases into IPv6 enabled networks. We further focus on the mobility architectures and determine the fundamental components of a mobility architecture. We then classify those approaches into centralized and distributed to show the current trends in terms of network mobility extension, an essential component to vehicular networking. We eventually analyze the performance of these proposals. In order to define an identifier namespace for vehicular communications, we introduce the Vehicle Identification Numbers are possible candidates. We then propose a conversion algorithm that preserves the VIN characteristics while mapping it onto usable IPv6 networking objects (ad-dresses, prefixes, and Mobile Node Identifiers). We make use of this result to extend LISP-MN protocol with the support of our VIN6 addressing architecture. We also apply those results to group IP-based communications, when the cluster head is in charge of a group of followers
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Baburam, Arun. "Adaptive mobility based clustering and hybrid geographic routing for mobile ad hoc networks." Thesis, University of Sussex, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.436822.
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Bani, Khalaf Mustafa. "Dynamic probabilistic routing discovery and broadcast schemes for high mobility ad-hoc networks." Thesis, Edinburgh Napier University, 2013. http://researchrepository.napier.ac.uk/Output/6151.
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Mobile Ad-hoc Networks (MANETs) have lately come to be widely used in everyday applications. Their usability and capability have attracted the interest of both commercial organizations and research communities. Recently, the Vehicular Ad-hoc Network (VANET) is a promising application of MANETs. It has been designed to offer a high level of safety for the drivers in order to minimize a number of roads accidents. Broadcast communication in MANETs and VANETs, is essential for a wide range of important services such as propagating safety messages and Route REQuest (RREQ) packets. Routing is one of the most challenging issues in MANETs and VANETs, which requires high efficient broadcast schemes. The primitive and widely deployed method of implementing the broadcast is simple ‘flooding'. In this approach, each node ‘floods' the network, with the message that it has received, in order to guarantee that other nodes in the network have been successfully reached. Although flooding is simple and reliable, it consumes a great deal of network resources, since it swamps the network with many redundant packets, leading to collisions contention and huge competition, while accessing the same shared wireless medium. This phenomenon is well-known in MANETs, and is called the Broadcast Storm Problem. The first contribution of this thesis is to design and develop an efficient distributed route discovery scheme that is implemented based on the probabilistic concept, in order to suppress the broadcast storm problem. The proposed scheme is called a Probabilistic Disturbed Route Discovery scheme (PDRD), and it prioritizes the routing operation at each node with respect to different network parameters such as the number of duplicated packets, and local and global network density. The performance of the proposed scheme PDRD has been examined in MANETs, in terms of a number of important metrics such as RREQ rebroadcast number and RREQ collision number. Experimental results confirm the superiority of the proposed scheme over its counterparts, including the Hybrid Probabilistic-Based Counter (HPC) scheme and the Simple Flooding (SF) scheme. The second contribution of this thesis is to tackle the frequent link breakages problem in MANETs. High mobility nodes often have frequent link breakages; this potentially leads to re-discovery of the same routes. Although different probabilistic solutions have been suggested to optimize the routing in MANETs, to the best of our knowledge they have not focused on the problem of frequent link breakages and link stability. II Unlike other existing probabilistic solutions, this thesis proposes a new Velocity Aware-Probabilistic (VAP) route discovery scheme, which can exclude unstable nodes from constructing routes between source and destination. The main idea behind the proposed schemes is to use velocity vector information to determine the stable nodes and unstable nodes. A proper rebroadcast probability and timer are set dynamically according to the node stability. Simulation results confirm that the new proposed scheme has much better performance in terms of end-to-end delay, RREQ rebroadcast number and link stability. The routing in VANETs is very critical and challenging in terms of the number of broken links and packet overheads. This is mainly due to the fast vehicles' speed and different vehicles' movement directions. A large number of routing protocols such as Ad-hoc On-demand Distance Vector (AODV) and Dynamic Source Routing (DSR) have been proposed to deal with the routing in MANETs. However, these protocols are not efficient and cannot be applied directly to VANETs context due to its different characteristics. Finally toward this end, this thesis proposes new probabilistic and timer probabilistic routing schemes in order to improve the routing in VANETs. The main aim of the proposed schemes is to set up the most stable routes to avoid any possible link breakage. These schemes also enhance the overall network performance by suppressing the broadcast storm problem, which occurs during the route discovery process. The proposed schemes also make AODV protocol suitable and applicable for VANETs. Simulation results show the benefit of the new routing schemes in terms of a number of metrics such as RREQ rebroadcast number, link stability and end-to-end delay.
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Bagayoko, Amadou Baba. "Politiques de robustesse en réseaux ad hoc." Thesis, Toulouse, INPT, 2012. http://www.theses.fr/2012INPT0056/document.
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Les réseaux sans fil sont sujets à des perturbations voire des pannes de liens et de noeuds en raison des caractéristiques intrinsèques de leur support de communication ; ces pannes sont aggravées par les particularités de relayage et de mobilité des noeuds dans les réseaux ad hoc. Ces réseaux requièrent donc la conception et la mise oeuvre des protocoles robustes au niveau de toutes les couches protocolaires. Dans cette thèse, nous choisissons une approche de robustesse pour améliorer les performances des communications dans un réseau mobile ad hoc. Nous proposons et étudions deux architectures de protection (protection par une analyse prédictive et protection par redondance de routes) qui sont couplées avec une restauration de niveau routage. Concernant la phase de détection, le protocole de routage utilise les notifications de niveau liaison pour détecter les pannes de liens. La première solution repose sur un protocole de routage réactif unipath dont le critère de sélection de routes est modifié. L’idée est d’utiliser des métriques capables de prédire l’état futur des routes dans le but d’améliorer leur durée de vie. Pour cela, deux métriques prédictives reposant sur la mobilité des noeuds sont proposées : la fiabilité des routes et une combinaison fiabilité-minimum de sauts. Pour calculer ces métriques prédictives, nous proposons une méthode analytique de calcul de la fiabilité de liens entre noeuds. Cette méthode prend compte le modèle de mobilité des noeuds et les caractéristiques de la communication sans fil notamment les collisions inter-paquets et les atténuations du signal. Les modèles de mobilité étudiés sont les modèles Random Walk et Random Way Point. Nous montrons l’impact de ces métriques sur les performances en termes de taux de livraison de paquets, de surcoût normalisé et de ruptures de routes. La seconde solution est une protection par redondance de routes qui s’appuie sur un protocole de routage multipath. Dans cette architecture, l’opération de recouvrement consiste soit à un basculement sur une route secondaire soit à une nouvelle découverte. Nous montrons que la redondance de routes améliore la robustesse de la communication en réduisant le temps de restauration. Ensuite, nous proposons une comparaison analytique entre les différentes politiques de recouvrement d’un protocole multipath. Nous en deduisons qu’un recouvrement segmenté donne les meilleurs résultats en termes de temps de restauration et de fiabilitéDue to the unreliability characteristics of wireless communications, and nodes mobility, Mobile Ad hoc Networks (MANETs) suffer from frequent failures and reactivation of links. Consequently, the routes frequently change, causing significant number of routing packets to discover new routes, leading to increased network congestion and transmission latency. Therefore, MANETs demand robust protocol design at all layers of the communication protocol stack, particularly at the MAC, the routing and transport layers. In this thesis, we adopt robustness approach to improve communication performance in MANET. We propose and study two protection architectures (protection by predictive analysis and protection by routes redundancy) which are coupled with a routing level restoration. The routing protocol is responsible of the failure detection phase, and uses the mechanism of link-level notifications to detect link failures. Our first proposition is based on unipath reactive routing protocol with a modified route selection criterion. The idea is to use metrics that can predict the future state of the route in order to improve their lifetime. Two predictive metrics based on the mobility of nodes are proposed : the routes reliability and, combining hop-count and reliability metrics. In order to determine the two predictive metrics, we propose an analytical formulation that computes link reliability between adjacent nodes. This formulation takes into account nodes mobility model and the the wireless communication characteristics including the collisions between packets and signal attenuations. Nodes mobility models studied are Random Walk and Random Way Point. We show the impact of these predictive metrics on the networks performance in terms of packet delivery ratio, normalized routing overhead and number of route failures. The second proposition is based on multipath routing protocol. It is a protection mechanism based on route redundancy. In this architecture, the recovery operation is either to switch the traffic to alternate route or to compute a new route. We show that the routes redundancy technique improves the communication robustness by reducing the failure recovery time. We propose an analytical comparison between different recovery policies of multipath routing protocol. We deduce that segment recovery is the best recovery policy in terms of recovery time and reliability
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Miao, Jingwei. "Message dissemination in mobile delay tolerant networks." Phd thesis, INSA de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00876589.
Full textAbstract:
Mobile Delay Tolerant Networks (MDTNs) are wireless mobile networks in which a complete routing path between two nodes that wish to communicate cannot be guaranteed. A number of networking scenarios have been categorized as MDTNs, such as vehicular ad hoc networks, pocket switched networks, etc. The network asynchrony, coupled with the limited resources of mobile devices make message dissemination (also called routing) one of the fundamental challenges in MDTNs. In the literature, a large body of work has been done to deal with routing in MDTNs. However, most of the existing routing protocols are based on at least one of the following three assumptions: (1) all messages can be routed by relying on a single mobility property; (2) all messages can be routed using a single message allocation strategy; (3) users are willing to disclose their mobility information and relationships to others in order to improve the quality of the routing. We argue that the above three assumptions are not realistic because: (1) users can exhibit various social behaviors and consequently various mobility properties (e.g., they can have regular movements during week-days and exhibit non-predictable movements during week-ends); (2) some messages might need more or less copies to be delivered according to the localization of the source and the destination and to the urgency of the message; and (3) users mobility data can disclose sensitive information about the users. In this thesis, we relieve MDTN routing from the above three restrictive assumptions. Firstly, we propose an adaptive routing protocol for mobile delay tolerant networks. The proposed protocol can dynamically learn the social properties of nodes based on their mobility patterns, and exploit the most appropriate routing strategy each time an intermediate node is encountered. Simulations performed on real mobility traces show that our protocol achieves a better delivery ratio than existing state-of-the-art routing protocols that rely on a single mobility property. Secondly, we present a delay and cost balancing protocol for efficient routing in mobile delay tolerant networks. The presented protocol reasons on the remaining time-to-live of a message to dynamically allocate the minimum number of copies that are necessary to achieve a given delivery probability. Evaluation results show that the protocol can achieve a good balance between message delivery delay and delivery cost, compared with most of the existing routing protocols in the literature. Lastly, we propose an efficient privacy preserving prediction-based routing protocol for mobile delay tolerant networks. This protocol preserves the mobility patterns of a node from being disclosed by exploiting the mobility pattern of communities that node belongs to. Evaluation results demonstrate that this protocol can obtain comparable routing performance to prediction-based protocols while preserving the mobility pattern of nodes.
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Princeton, Judith, and Judith Princeton. "Pratiques innovantes d'exploitation des réseaux routiers en lien avec une mobilité durable : une nouvelle approche de l'évaluation." Phd thesis, Université Paris-Est, 2011. http://tel.archives-ouvertes.fr/tel-00703206.
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La gestion du trafic sur les réseaux routiers se heurte aux nouveaux enjeux du développement durable. L'objectif n'est plus seulement de proposer aux usagers des temps de parcours raisonnables. Il faut aussi limiter la consommation énergétique et les émissions des gaz à effet de serre et des polluants qui y sont associées, afin de garantir une meilleure qualité de vie pour les générations actuelle et futures. Les exigences en matière de sécurité routière sont également renforcées et visent à éliminer le nombre de tués sur les routes. Les exploitants ont donc recours à diverses stratégies, souvent innovantes, pour au moins approcher la situation idéale. Néanmoins, si les décideurs disposent d'une plus grande capacité à mettre en œuvre leurs programmes dans le domaine, ils ont également l'obligation d'en évaluer les performances à divers stades. Cette thèse analyse les nouvelles stratégies de gestion des réseaux autoroutiers en identifiant leurs domaines d'application ainsi que leurs impacts potentiels et réels. Les limites des méthodes existantes d'évaluation a priori et/ou a posteriori sont mises en évidence et une nouvelle approche est proposée. Celle-ci associe les trois principaux critères d'une mobilité durable à un seul concept: le niveau de service, largement employé par les exploitants de réseaux. La méthodologie a fait l'objet d'une validation sur différentes opérations. Par ailleurs, se basant sur les résultats obtenus sur un ensemble d'opérations d'affectation variable des voies au niveau européen, la thèse propose un outil d'aide au choix d'une stratégie d'exploitation d'un réseau en fonction de la configuration de l'infrastructure et du niveau de congestion. Cet outil se présente sous la forme d'un catalogue de cas-types applicable au réseau d'Ile-de-France. La nouvelle approche d'évaluation proposée dans cette thèse présente l'intérêt de pouvoir facilement s'intégrer aux outils de simulation du trafic. Les impacts d'une opération d'exploitation routière sur la congestion, la sécurité et l'environnement peuvent ainsi être fournis par ces simulateurs dans le cadre de l'évaluation a priori. L'intégration est également possible au niveau des systèmes des centres de gestion du trafic, pour l'évaluation a posteriori. Par ailleurs, la thèse identifie des pistes potentielles pour des investigations futures. Tout d'abord, la gravité des accidents pourrait être prise en compte dans l'approche d'évaluation proposée, qui considère pour l'instant tous les accidents corporels confondus en raison du manque de données. De même, seules quatre stratégies d'affectation variable des voies sont proposées dans le catalogue de cas-types. Celui-ci pourrait donc être étendu à l'ensemble des opérations d'exploitation en suivant la même méthodologie décrite dans la thèse
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Princeton, Judith. "Pratiques innovantes d'exploitation des réseaux routiers en lien avec une mobilité durable : une nouvelle approche de l'évaluation." Thesis, Paris Est, 2011. http://www.theses.fr/2011PEST1152/document.
Full textAbstract:
La gestion du trafic sur les réseaux routiers se heurte aux nouveaux enjeux du développement durable. L'objectif n'est plus seulement de proposer aux usagers des temps de parcours raisonnables. Il faut aussi limiter la consommation énergétique et les émissions des gaz à effet de serre et des polluants qui y sont associées, afin de garantir une meilleure qualité de vie pour les générations actuelle et futures. Les exigences en matière de sécurité routière sont également renforcées et visent à éliminer le nombre de tués sur les routes. Les exploitants ont donc recours à diverses stratégies, souvent innovantes, pour au moins approcher la situation idéale. Néanmoins, si les décideurs disposent d'une plus grande capacité à mettre en œuvre leurs programmes dans le domaine, ils ont également l'obligation d'en évaluer les performances à divers stades. Cette thèse analyse les nouvelles stratégies de gestion des réseaux autoroutiers en identifiant leurs domaines d'application ainsi que leurs impacts potentiels et réels. Les limites des méthodes existantes d'évaluation a priori et/ou a posteriori sont mises en évidence et une nouvelle approche est proposée. Celle-ci associe les trois principaux critères d'une mobilité durable à un seul concept: le niveau de service, largement employé par les exploitants de réseaux. La méthodologie a fait l'objet d'une validation sur différentes opérations. Par ailleurs, se basant sur les résultats obtenus sur un ensemble d'opérations d'affectation variable des voies au niveau européen, la thèse propose un outil d'aide au choix d'une stratégie d'exploitation d'un réseau en fonction de la configuration de l'infrastructure et du niveau de congestion. Cet outil se présente sous la forme d'un catalogue de cas-types applicable au réseau d'Ile-de-France. La nouvelle approche d'évaluation proposée dans cette thèse présente l'intérêt de pouvoir facilement s'intégrer aux outils de simulation du trafic. Les impacts d'une opération d'exploitation routière sur la congestion, la sécurité et l'environnement peuvent ainsi être fournis par ces simulateurs dans le cadre de l'évaluation a priori. L'intégration est également possible au niveau des systèmes des centres de gestion du trafic, pour l'évaluation a posteriori. Par ailleurs, la thèse identifie des pistes potentielles pour des investigations futures. Tout d'abord, la gravité des accidents pourrait être prise en compte dans l'approche d'évaluation proposée, qui considère pour l'instant tous les accidents corporels confondus en raison du manque de données. De même, seules quatre stratégies d'affectation variable des voies sont proposées dans le catalogue de cas-types. Celui-ci pourrait donc être étendu à l'ensemble des opérations d'exploitation en suivant la même méthodologie décrite dans la thèseTraffic management is facing the new issues of the sustainable development concept. The objective is not only to guarantee acceptable travels times over the networks anymore. Energy consumption as well as associated greenhouse gaz and pollutant emissions must be reduced for a better quality of life for current and future generations. Standards in road safety have also been reinforced and aim at cutting off the number of accident fatalities. Thus, traffic operators use the most innovating strategies. Nevertheless, if decision-makers have greater possibilities to implement their programmes, they also are committed to assess their performance at different stages. This doctoral thesis analyses the new strategies in motorway network management by identifying their respective domains of application as well as their potential and real impacts. Limitations of existing a priori and a posteriori evaluation methods are highlighted and a new approach is proposed. It associates the three main criteria of sustainable mobility to one concept: the level of service, which is widely used by network operators. The methodology is validated on several operations. Besides, based on results obtained from the various lane management operations implemented all accross Europe, the thesis proposes a tool to help in choosing the appropriate strategy according to the motorway layout and congestion level. The tool is presented in the form of a catalog of typical cases for the Ile-de-France motorway network. The new evaluation approach proposed in this thesis may be easily integrated in the available traffic simulation tools. Hence, the impacts of a traffic management operation on congestion, safety and the environment may be obtained as output from those simulators in the framewok of an a priori evaluation. This integration is also possible in the traffic management center systems, for a posteriori evaluations. Besides, the thesis identifies potential subjects for future research. Firstly, accident severity could be considered in the proposed evaluation approach, which takes into account all injury accidents at once by now, due to a lack of data. Likewise, only four manged lane strategies are included in the catalog, which could be extended to all the existing traffic management operations through the same methodology described in the thesis
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Tahooni, Mohammad. "Mobility-based Candidate Selection and Coordination in Opportunistic Routing for Mobile Ad-Hoc Networks." Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/31604.
Full textAbstract:
Opportunistic Routing (OR) is an effective and enhanced routing scheme for wireless multihop environment. OR is an approach that selects a certain number of best forwarders (candidates) at each hop by taking the advantage of the broadcast nature of the wireless medium to reach the destination. When a set of candidates receive the packet, they coordinate with each other to figure out which one has to forward the packet toward the destination. Most of the research in this area has been done in mesh networks where nodes do not have mobility.
In this survey, we propose a new OR protocol for mobile ad hoc scenarios called as Enhanced Mobility-based Opportunistic Routing (EMOR) protocol. To deal with the node mobility, we have proposed a new metric which considers the following: geographical position of the candidates; the link delivery probability to reach them; the number of neighboring nodes of candidates; and the predicted position of nodes using the motion vector of the nodes. We have compared EMOR with five other well-known routing protocols in terms of delivery ratio, end-to-end delay, and expected number of transmissions from source to the destination. Our simulation results show that proposed protocol improves delivery ratio and number of expected transmission in terms of different type of mobility models.
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Costantini, Hervé. "La mobilité sociale : Modèles et traces." Phd thesis, Conservatoire national des arts et metiers - CNAM, 2012. http://tel.archives-ouvertes.fr/tel-00770978.
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L'avenir de la communication est perçu comme étant quasiment exclusivement constitué de nœuds mobiles évoluant dans un réseau mobile. Dans ce contexte, différentes approches contribuent continuellement à l'amélioration directe ou indirecte des délais d'acheminement des informations échangées entre les utilisateurs, dont :- l'analyse des traces;- l'évaluation des performances ;- les services de localisation;- le routage. Nous décrivons chacun de ses thèmes et proposons des solutions faisant évoluer l'état de l'art. Celles-ci prennent appui sur des méthodes et outils tels que :- les Réseaux de Petri, pour l'analyse des traces ;- les modèles de mobilité, pour l'évaluation des performances;- l'introduction du social dans les services de localisation;- la mise en place d'une nouvelle métrique pour le routage. Nous montrons comment ces solutions concourent de façon complémentaire les unes avec les autres, à améliorer l'expérience de l'utilisateur.
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Drevelle, Matthieu. "Desservir les faibles densités par les transports collectifs routiers : des réseaux aux prises avec le territoire." Thesis, Paris 1, 2015. http://www.theses.fr/2015PA010634.
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Discutant la thèse d’un périurbain indifférencié, cette thèse cherche à définir les différences spatiales entre les couronnes périurbaines françaises et à identifier l’impact de ces différences sur le coût de desserte des couronnes par les transports collectifs. Portant sur une centaine de couronnes périurbaines, l’étude de morphologie et de la granulométrie des ilots périurbains permet de classifier différents types de formes périurbaines et d’analyser leur répartition sur le territoire. Le croisement de cette typologie avec les coûts de desserte (selon différents scénarios) permet de mettre en évidence les formes de périurbanisation les plus « vertueuses » en matière de desservabilité La comparaison des différents scénarios de desserte permet d’identifier les organisations de réseaux les plus efficaces. Visant à ajouter une dimension « pratiques de mobilité » et « bonnes pratiques d’aménagement » à ces premiers résultats, la thèse propose une étude de cas sur l’aire urbaine de Montpellier. Cette partie ouvre la réflexion sur les pratiques de mobilité des périurbains en lien avec l’émergence de pôles secondaires à l’extérieur des villes-centres. Une certaine autonomie du périurbain est alors la mise en évidence. Face à cette dilution des centralités, l’articulation entre réseaux urbains et interurbains apparait nécessaire de favoriser l’accessibilité aux ressources humaines éclatées dans l’ensemble de l’agglomération. La synthèse de ces réflexions permet alors d’esquisser un nouveau mode de transport, adapté aux espaces périurbains, aux besoins des habitants et aux évolutions des territoires agglomérés : la Car à Haut Niveau de ServiceThis Ph.D aims to show that french periurban areas are different each other : morphology and size of settlements differs according to which part of the country the city is in. A georgraphy of French periurban areas is proposed. Then the author compares periurban patterns with public transport costs that serve theses areas (using theoretical networks created for this work). It allows showing how some periurban patterns may be easier to serve with public transports than others. In a second time a case study is proposed for the agglomeration of Montpellier. This case study gives clues to understand new mobility patters in low density areas and the emergence of polarities outside of the historical city. These new urban dynamics highlights the need of a better organization between public transports and intercity public transportation : in fact networks have to adapted to maintain accessibility to urban amenities. These elements lead to adapt the concept of BRT to low densities areas
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Harfouche, Leïla. "Vers une intégration des comportements communautaires dans les réseaux mobiles." Thesis, Paris, CNAM, 2011. http://www.theses.fr/2011CNAM0790/document.
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À l'aire du Multimedia Mobile, l'essor des réseaux sans fil est fulgurant et la mobilité est devenue un sujet primordial exacerbé par l'augmentation significative du nombre d'usagers mobiles. Un nœud évoluant dans un réseau mobile de base se comporte de la même manière qu'un aveugle évoluant dans notre univers en en élaborant sa propre représentation à l'aide de son bâton, mécanisme dénommé dans la littérature : mobilité terminale. Pour réduire cet aveuglement, plusieurs méthodes ont été élaborées qui prennent appui sur les services de localisation ou les modèles de mobilité. Un modèle de mobilité est donc destiné à décrire en termes d'environnement, le mode de circulation des nœuds mobiles avec pour défi de trouver des modèles fidèles aux comportements des utilisateurs. Les modèles aléatoires sont biaisés car les appareils mobiles sont portés par des êtres sociaux. Cela nous a amené à inclure des éléments sociaux dans notre modélisation.Nous présentons les modèles de mobilité existants et les classifions. Nous définissons nos modèles, les implémentons et mesurons leur impact sur le test des réseaux. Enfin nous élargissons notre spectre en montrant comment le fait d'octroyer la perception de regroupement social à un protocole de routage réseau, peut en améliorer les performancesIn our area of Mobile Multimedia, the expansion of wireless networks is dazzling and mobility has become a major issue exacerbated by the significant increase in the number of mobile users.A node operating in a basic mobile network behaves the same way a blind person moving in our universe by developing its own representation with his stick, a mechanism known in the literature as terminal mobility. To reduce this blindness, several methods have been developed that are based on location services and mobility models.A mobility model is then intended to describe in terms of environment, the motion criteria of mobile nodes with the challenge to find models faithful to user behavior.Random models are biased because mobile devices are supported by social beings. This led us to include social elements in our models.We present the existing mobility models and classify them.We define our models, implement them and measure their impact on the network testing.Finally we expand our spectrum by showing that granting social grouping perception to a network routing protocol, can improve its performance
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Yousfi, Badr-Eddine. "Dynamiques urbaines, mobilités et transports dans le Sud-ouest algérien (wilayas d'Adrar et de Bechar)." Thesis, Besançon, 2012. http://www.theses.fr/2012BESA1007/document.
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Entre une perspective régionale de l’aménagement du territoire et une vision géopolitique de la région « Sahel, Maghreb », l’Etat algérien s’est engagé depuis la deuxième décennie de son indépendance non seulement à développer les transports dans les zones sahariennes mais aussi à mettre en place les équipements nécessaires pour le développement économique et social de ces zones, en desservant presque la totalité des centres urbains. Dans le Sud-ouest, cette dynamique a remodelé profondément l’espace relationnel dans la Saoura, le Gourara et le Touat. Structuré autrefois par les routes du commerce caravanier transsaharien, cet espace se désenclave, se voit attribuer de nouvelles fonctions et s’urbanise. Une nouvelle réorganisation de l’espace se met en place à l’échelle urbaine, rurale et régionale dans laquelle la ville se recompose et constitue le moteur d’insertion de ces territoires dans l’espace national. Soutenu par un nouveau réseau de transport routier, la dynamique urbaine dans le Sud-ouest algérien a concouru à dynamiser la mobilité intra-saharienne, redéfinissant ainsi de nouvelles relations spatiales entre la ville et son arrière pays mais aussi entre le Sud et le Nord. L’avènement d’une nouvelle composante humaine dans les centres urbains a entrainé des changements des rapports sociaux dans la société locale et le développement de nouveaux pratiques et comportements de consommation. La question de mobilité s’inscrit essentiellement autour de certaines logiques connues : politique, économique, sociale et culturelle, mais elle est surtout le produit de stratégies inconnues, de pratiques et d’enjeuxBetween a regional perspective of the territorial (spatial) planning and a geopolitical vision of the region " Sahel, the Maghreb ", the Algerian State made a commitment since the second decade of its independence not only to develop transport in the Saharan zones but also to set up the necessary equipments for the economical and social development of these zones, by serving almost the totality of the urban areas. In the Southwest, this dynamics remodelled profoundly the relational space in Saoura, Gourara and Touat.Structured formerly by the roads of the trans-Saharan caravan business, this space opens up, attributes new functions and becomes urbanized. A new reorganization of the space is set up in the urban, rural and regional scale in which the city recomposes and constitutes the insertion engine of these territories in the national space. Supported by a new road transport network, the urban dynamics in the Algerian Southwest contributed to revitalize the intra-Saharan mobility, and so it is redefining not only new spatial relations between the city and its back country but also between the South and the North. The succession of a new human component in urban areas has entrained the changes of the social reports in the local company and the development of new practices and consumer behaviors. The question of mobility centers essentially around certain known logics: Political, economic, social and cultural, but it is especially the product of unknown strategies, practices and stakes
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Tahir, Saleem. "Performance Issues of Routing Protocols in MANET." Thesis, Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-2681.
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A mobile ad-hoc network is an assortment of wireless mobile hosts, which establishes a momentary network without any assist of centralized administrator. The characteristics of an ad-hoc network can be explored on the base of routing protocols. The dynamic topology is the vital characteristic in which nodes frequently change their position. In the ad-hoc networks, there are mobile nodes such as Personal Digital Assistance (PDA), smart phone and laptops; they have limited operational resources like battery power and bandwidth. The control traffic is to be minimized, which is the main responsibility of routing protocols by selecting the shortest path and controlling the traffic. In this study work, we focus on performance issues of routing protocols, Optimized Link State Routing (OLSR), Ad Hoc On-Demand Distance Vector (AODV), Dynamic Source Routing (DSR), and Temporally Ordered Routing Algorithm (TORA) in mobility and standalone ad-hoc networks. For this purpose, we first study and explain these protocols and then we use the Optimized Network Engineering Tool (OPNET) modeler tool and analyze the performance metrics delay, throughput and network load.
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Alash, Hayder Majid Abdulhameed. "Impact of Mobility Models on Routing Protocols for Various Traffic Classes in Mobile Ad Hoc Networks." Kent State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=kent1461022411.
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RAJSHIVA, KIRTIMAAN. "PERFORMANCE ENHANCEMENTS FOR Ad Hoc NETWORKS USING MOBILITY-LOCATION INFORMATION." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1132338696.
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Chen, Chao. "Advanced Routing Protocols for Satellite and Space Networks." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7107.
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Satellite systems have the advantage of global coverage and offer a solution for providing broadband access to end users. Local terrestrial networks and terminals can be connected to the rest of the world over Low Earth Orbit (LEO) satellite networks simply by installing small
satellite interfaces. With these properties, satellite systems play a crucial role in the global Internet to support real-time and non-real-time applications. Routing in satellite networks, and the integration of satellite
networks and the terrestrial Internet are the key issues to support these services.
Furthermore, the developments in space technologies enable the realization of deep-space missions such as Mars exploration. The Interplanetary Internet is envisioned to provide communication services for scientific data delivery and navigation services for the explorer spacecrafts and orbiters of future
deep-space missions. The unique characteristics posed by deep-space communications call for different research approaches from those in
terrestrial networks.
The objective of this research is to develop advanced architectures and efficient routing protocols for satellite and space networks to support applications with different traffic types and heterogeneous quality-of-service
(QoS) requirements. Specifically, a new QoS-based routing algorithm (QRA) is proposed as a
connection-oriented routing scheme to support real-time multimedia applications in satellite networks. Next, the satellite grouping and routing protocol (SGRP) is presented as a
unicast routing protocol in a two-layer satellite IP network architecture. The border gateway protocol - satellite version (BGP-S) is then proposed as a unified routing protocol to accomplish the integration of the terrestrial and satellite IP networks at the network layer.
Finally, a new routing framework, called the space backbone routing (SBR), is introduced for routing through different autonomous regions in the Interplanetary Internet. SBR provides a self-contained and scalable solution to support different traffic types through the Interplanetary Internet.
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Paudel, Bandana. "On the effects of small-scale fading and mobility in mobile wireless communication network." Diss., Rolla, Mo. : Missouri University of Science and Technology, 2009. http://scholarsmine.mst.edu/thesis/pdf/Paudel_09007dcc806c00f9.pdf.
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Thesis (M.S.)--Missouri University of Science and Technology, 2009.Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed August 25, 2009) Includes bibliographical references (p. 71-73).
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Cadger, Fraser William. "A location and mobility-aware routing framework for improving multimedia streaming performance in Mobile Ad-hoc Networks." Thesis, Ulster University, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.658198.
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Crevier, Geneviève. "Analyse de la circulation des aides à la mobilité sur le réseau routier avant et après l'introduction d'un cadre légal." Mémoire, Université de Sherbrooke, 2017. http://hdl.handle.net/11143/10642.
Full textAbstract:
Étant donné la circulation croissante des utilisateurs d’aides à la mobilité motorisées (AMM) sur les voies publiques et le fait que le Code de la sécurité routière du Québec ne définit ni statut, ni règle de circulation s’appliquant à ces derniers, une volonté d’encadrer l’utilisation de ces appareils sur le réseau routier a été manifestée par les instances gouvernementales, qui ont procédé à l’introduction de nouvelles règles en juin 2015, à l’aide d’un arrêté ministériel.
L’objectif de ce projet consiste à vérifier les effets de la loi à la suite de l’entrée en vigueur du cadre légal. Les habitudes de circulation et le comportement des utilisateurs d’AMM dans différents environnements routiers sont décrits en fonction des conditions réelles de leurs déplacements avant et après l’introduction du cadre légal. En effectuant les mêmes observations avant et après l’entrée en vigueur des nouvelles règles, il est possible de déterminer si le cadre légal a eu un effet sur le comportement et les habitudes de circulation des utilisateurs d’AMM. L’approche consiste à coupler des données vidéo et géospatiales à un Système d’information géographique (SIG), afin de développer des indicateurs de mobilité et de sécurité. Les bandes audio et vidéo enregistrées lors du déplacement permettent d’obtenir plusieurs commentaires de la part des utilisateurs et permettent aussi de mesurer objectivement les déplacements. Les données GPS permettent de connaître la position de l’utilisateur, la vitesse et la durée de ses déplacements.
Les résultats montrent que les utilisateurs ont modifié certaines habitudes après l’entrée en vigueur des nouvelles règles. Premièrement, un changement a été observé quant au sens de circulation sur la chaussée. Ils étaient 72,6 % avant l’arrêté ministériel à circuler dans le même sens que les véhicules, alors qu’ils étaient 83,1 % à le faire après l’arrêté (p < 0,01). D’autres indicateurs ont enregistrés des variations significatives, mais seulement en fonction d’un milieu, d’un type d’appareil ou d’un environnement-type. Par exemple, on a observé :
• une augmentation de la vitesse moyenne sur les trottoirs, mais à Montréal seulement (+1,4 km/h ; p=0,04) ;
• une augmentation de la vitesse moyenne sur la chaussée, mais seulement chez les utilisateurs de triporteur et de quadriporteur (+1,5 km/h ; p=0,02) ;
• lorsque l’infrastructure possédait à la fois un trottoir, une voie cyclable et une chaussée, une diminution de l’utilisation de la chaussée a été observée après l’arrêté (-11,4% ; p=0,03).
En conclusion, trois années s’étant écoulées entre les deux collectes, certains éléments extérieurs au cadre légal pourraient expliquer les changements intervenus. Il appert toutefois difficile de savoir si tous les changements observés sont un réel effet de la loi ou s’ils sont dus à d’autres facteurs évolutifs ou personnels dans les déplacements.
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Touhbi, Saâd. "Élaboration d’un modèle multi-agents pour la génération synthétique de trafic : application à la mobilité urbaine de la ville de Marrakech." Electronic Thesis or Diss., Sorbonne université, 2018. http://www.theses.fr/2018SORUS326.
Full textAbstract:
La génération de trafic est un processus indispensable dans la simulation du trafic. Ce processus permet de définir une série d’arrivées des véhicules dans une route. Cette série est prouvée aléatoire depuis 1930. Toutefois, sa distribution reflète à un niveau le comportement de conduite. L’objectif de notre thèse est de mettre en place un outil de génération de trafic permettant de définir le point d’arrivée du véhicule dans une route, identifier le choix de type du véhicule, définir son temps d’arrivée, et lui affecter une vitesse initiale. Une première étape faite dans ce sens est la modélisation d’arrivée, particulièrement le TIV, en mettant en place un protocole d’analyse de cette variable en quatre étapes : traitement des données d’arrivée des véhicules et calcul de la variable TIV, définir des échantillons représentant différents niveaux de trafic, le choix des modèles probabilistes et estimation des paramètres, comparaison des modèles estimés et les données empiriques. Une application numérique est effectuée sur quatre routes à trois voies chacune interrompue par un feu de signalisation à la ville de Marrakech. On en conclut que Le modèle de Pareto IV est non rejeté pour les différents niveaux de trafic. Le modèle Exponentiel est prouvé inadéquat dans les différents niveaux de trafic. Le modèle Log-Normal et le modèle de Pearson type III sont adéquats pour des niveaux de trafic intermédiaire et élevé. Ces résultats ont permis de tester l’utilisabilité de notre outil de génération de trafic sous différentes modalités. L’outil permet de générer un niveau trafic cohérent avec celui désiré. Une première intégration a été faite pour la simulation MarrakAir permettant d’estimer les polluants automobiles en se basant sur le trafic. Ceci afin d’éliminer la nécessité d’avoir des données ponctuelles sur l’arrivée des véhiculesTraffic generation is an important process in traffic simulation. It defines a series of vehicle arrival at a road. This series is proven to be random since 1930. However, its distribution explains at a level the behavior of the motorists. The goal of this thesis is to establish a traffic generation toolbox to produce a series of vehicle arrival characterized by their entry point, their type, arrival time and their initial speed. A first step was to establish an analysis protocol for the time headway (TH) of the arriving vehicles consisting of four steps : (i) data processing and calculating TH, (ii) sampling of data according to different levels of traffic, (iii) model choice and estimation, (iv) and the comparison of the estimated models and the empirical data. The application of the latter on four roads with three lanes interrupted by a signalized intersection showed that : The Pareto IV model is not rejected for all levels of traffic in these roads, the Exponential model is proven to be inadequate for all levels of traffic, the Log-Normal and Pearson III are best suited for intermediate to high levels of traffic. These results helped in testing the traffic generation toolbox proving that it generates coherent level of traffic compared to the desired configuration. The latter was integrated in the simulation MarrakAir that estimated the level of pollution based on traffic. This was done to eliminate the necessity to have punctual data from sensors about vehicle arrivals
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Berlini, Filippo. "Tecniche e algoritmi di aggregate computing a supporto di contesti di smart mobility." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/14292/.
Full textAbstract:
Il terzo millennio ha portato con sé importanti innovazioni tecnologiche nell'ambito dell'informatica che hanno causato modifiche sostanziali nel modo di vivere e di pensare delle persone. Al giorno d'oggi non vi è soggetto che esca di casa senza il proprio smartphone, questo ci porta ad essere sempre muniti di un dispositivo computazionale con un'elevata capacità di calcolo. La diffusione di questi device, in aggiunta alla crescita di dispositivi in rete, ha portato allo studio e lo sviluppo di sistemi basati sull'Internet of Things (IoT). Lo studio e lo sviluppo di tali sistemi offrono grandi potenzialità che non riescono però ad essere pienamente sfruttate a causa di un supporto tecnico non adeguato.
Un'altra conseguenza dello sviluppo e della diffusione dei device computazionali sono i sistemi di Smart City e gli studi ad essi associati. La Smart City, in tutti i suoi ambiti, è in fervente crescita e lo sviluppo e il progresso tecnologico le offrono sempre nuove potenzialità. Grazie ai finanziamenti delle istituzioni internazionali che supportano questo tipo di ricerca, il processo di evoluzione è continuo.
La progettazione di un sistema distribuito, come è di fatto l'IoT, è per sua natura complessa. Gli approcci utilizzati finora per lo sviluppo di questi sistemi si sono mostrati frequentemente inadeguati o poco efficaci. È proprio in questo ambito che si inserisce l'Aggregate Programming. Lo studio di questa tesi vuole mostrare infatti come l'Aggregate Programming offra un modo di
interpretare e pensare in termini di sistemi distribuiti capace di sfruttare le potenzialità che questi sistemi offrono. Nella presente tesi si pone in particolare attenzione alla Smart Mobility con lo scopo di mostrare possibili soluzioni algoritmiche nell'ambito della gestione del traffico e della viabilità utilizzando l'Aggregate Programming.