No description available.

Edouard Manet's paintings of working-class women reflect the dramatic social changes which occurred in Paris during the late nineteenth century. This thesis examines Manet's paintings which represent some of the sites of femininity within modern Paris: the home and garden, the prostitute's bedroom, and the new public sphere of the boulevards and cafes. With references to contemporary writings and social histories, the result of this study is a more profound understanding of how Modernism affected women's lives and the way in which they were represented in art.

This diploma thesis focuses on the MANET Network (Mobile Ad-Hoc Network). There are theoretically elaborated basic information, the characteristics of the MANET network and great emphasis is placed on routing in these networks. In the next chapter the diploma thesis focuses on the Ad Hoc Demand Distance Vector (AODV) routing protocol. It features the characteristics of this protocol and the principle of communication and routing in MANET networks. Hereinafter, the individual reports of the AODV protocol are described in detail. In the third chapter, the thesis introduces the NS-3 simulation environment (network Simulator - 3) and then deals with the design of the MANET network in NS-3 using the AODV routing protocol. The practical part of the diploma thesis is the MANET network simulation and testing with the AODV routing protocol. Laboratory task is built from these simulations and the results of the testing.

An ad hoc mobile network is a collection of mobile nodes that are dynamically and arbitrarily located in such a manner that the interconnections between nodes are capable of changing on a continual basis. In order to simplify communication within the network, a routing protocol is used to discover routes between nodes. The primary goal of such an ad hoc network routing protocol is correct and efficient route establishment between a pair of nodes so that messages may be delivered on time. Route construction should be done with a minimum of overhead and bandwidth consumption. This document describes the Optimized Link State Routing (OLSR) protocol for mobile ad hoc networks. The key concept used in the protocol is that of multipoint relays (MPRs). MPRs provide an efficient mechanism for flooding control traffic by reducing the number of transmissions required.

No description available.

The exchange of topology information is a potential attack target in mobile ad-hoc networks. To provide an intrinsic security mechanism, it is possible to validate topology advertisements in the control plane against records of the path taken by transmission in the data plane. In this work, different path recording mechanisms are discussed. Their performance - in terms of packet overhead and reconstruction complexity - is analyzed and evaluated.

This research investigated key management in a Mobile Ad Hoc Network (MANET) environment. At the time this research began key management schemes provided limited functionality and low service availability in a highly partitioned ad hoc environment. The purpose of this research was to develop a framework that provides redundancy and robustness for Security Association (SA) establishment between pairs of nodes. The key contribution of this research is the Key Management System (KMS) framework and, more specifically, the unique way the various components are integrated to provide the various functionalities. The KMS overcomes the limitations of previous systems by (1) minimizing pre-configuration, (2) increasing service availability, (3) and increasing flexibility for new nodes joining the network. A behavior grading scheme provides the network with a system-wide view of the trustworthiness of nodes and enables the KMS to dynamically adjust its configuration according to its environment. The introduction of behavior grading allows nodes to be less dependent on strict identity verification. This KMS was simulated with Monte Carlo and NS2 simulations and was shown to interoperate with IP Security (IPsec) to enable the establishment of IPsec SAs. The simulations have proven the effectiveness of the system in providing service to the nodes in a highly partitioned environment. / Ph. D.

Mobile Ad hoc NETworks (MANETs) are networks in which the participating nodes can move freely without having to worry about maintaining a direct connection to any particular fixed access point. In a MANET, nodes collaborate with each other to form the network and as long as a node is in contact with any other member of the network, it—at least in theory—is part of the network and can communicate with all other nodes. An important function of network management is to observe current network conditions: at the node level, this may mean keeping track of arriving and departing traffic load; at the network level, the system must monitor active routes and changes in network topology. In this research, we present the design and implementation of a distributed network monitoring system for MANETs. Our system is completely distributed, generates no additional traffic on the network and produces a dynamic picture of the network level and node level information on a graphical user interface. In our proposed scheme, multiple monitoring nodes collaborate to achieve a reasonably accurate snapshot of the network conditions. These monitoring nodes passively sniff network traffics and gather information from the network to construct partial network views. They then transmit their findings to a management unit where these local views are put together to produce a comprehensive picture of the network. The communication between all management nodes (a monitoring unit and a management node) takes place in an out-of-band communication link. Therefore, our monitoring solution does not depend on the MANET to perform, hence is robust to network partitioning, link breaks, node's death and node misbehavior in the monitored MANET. Our solution provides a snapshot of the network topology that includes information about node-level behavior ratings and traffic activity. The information provided by our monitoring system can be used for network management as well as for security assessment, including anomaly detection. Information regarding individual nodes' behavior can be used for detecting selfishness in the network. Also, an approximation of arriving and departing traffic levels at each node is important in the context of quality of service, load balancing and congestion control. Furthermore, the network topology picture can provide valuable information to network management in detecting preferred routes, discovering network partitioning and in fault detection. We developed a proof-of-concept implementation of our system, which works with the Optimized Link State Routing (OLSR) protocol. Through experimental studies with up to 10-node MANETs, we were able to determine the feasibility and workability of our system. The scheme proved to be robust with respect to mobility, rapid changes in the network topology and node connectivity. Throughout our experiments we observed that our system replicated changes in the network on the GUI with less than two seconds delay. Also, when deployed in a high-traffic environment, with multiple TCP and UDP flows throughout the network, the system was able to report traffic load on each node accurately and consistently. On average, CPU consumption on monitoring nodes was about 3.5% and the GUI never took up more than 4% of the processing power (general-purpose laptop computers were used throughout the experiments). Also, the overall storage capacity needed for archiving the information files was estimated as 1 Mbytes for monitoring a 10-node MANETs for 30 minutes. Unobtrusive and distributed nature of our proposed approach helps the system to adapt to the constantly changing nature of MANETs and be able to provide valuable network management, security assessment and traffic analysis services, while requiring only modest processing and storage resources. The system is capable of quickly responding to changes in the network and is non-intrusive, generating no additional traffic on the MANET it monitors. / Master of Science

Ces deux dernières décennies les systèmes P2P de partage de fichiers sont devenus très populaires grâce aux accès à des ressources diverses, distribuées sur Internet. Parallèlement à l'évolution de cette catégorie de systèmes, les dispositifs mobiles (téléphones cellulaires, PDA et autres appareils portatifs) ont eu un grand succès sur le marché. Équipés d'une technologie de communication sans fil (Bluetooth, et Wifi), ils peuvent communiquer sans nécessiter une infrastructure particulière en utilisant un réseau mobile adhoc (Mobile Adhoc NETwork -MANET). De la même manière, les systèmes P2P peuvent être aussi déployés sur ce type de réseau et deviennent des systèmes P2P mobiles (Mobile 2P systems). Dans le cadre de cette thèse, nous nous intéressons essentiellement à la recherche d'information dans les systèmes P2P et plus précisément au problème de routage de requêtes. La première partie de la thèse, s'est focalisée sur le routage de requêtes dans les systèmes P2P sur Internet. Nous avons proposé (i) un modèle de routage sémantique basé sur l'historique des requêtes. Ce modèle est ensuite instancié pour définir une nouvelle méthode de routage par apprentissage. Pour pallier le problème de démarrage à froid, (ii) nous avons proposé une méthode prédictive de l'intention de l'utilisateur qui construit une base de connaissances à priori pour chaque pair. Enfin, (iii) nous avons proposé une méthode de routage hybride pour traiter le problème d'échec de sélection. Cette méthode est basée sur l'historique des requêtes et le regroupement de pairs dans des groupes sémantiques. La deuxième partie de la thèse, s'est focalisée sur le routage de requêtes dans les systèmes P2P mobiles. L'apparition des MANETs, a soulevé de nouveaux challenges de routage. Ces réseaux souffrent de plusieurs contraintes liées aux supports de transmission ou bien aux dispositifs mobiles. Dans ce cadre, nous avons proposé une méthode de routage pour les systèmes P2P non structurés mobiles basée sur le contexte de l'utilisateur. D'un point de vue technique, toutes ces propositions ont été développées, validées et évaluées grâce aux simulateurs PeerSim et NS2 / Peer-to-peer systems have emerged as platforms for users to search and share information over the Internet. In fact, thanks to these systems, user can share various resources, send queries to search and locate resources shared by other users. Nowadays, mobile and wireless technology has achieved great progress. These devices are also equipped with low radio range technology, like Bluetooth and Wi-Fi, etc. By means of the low radio range technology, they can communicate with each other without using communication infrastructure (e.g. Internet network) and form a mobile ad hoc network (MANET). Hence, P2P file sharing systems can be also deployed over MANET. A challenging problem in unstructured P2P systems is query routing. Researches' efficiency and effectiveness can be improved by making smart decisions for query routing. Our contributions, in this thesis, focus on two complementary axes. Firstly, our research work focalized on P2P systems over Internet. We introduced a novel semantic model for query routing based on past queries, thereafter we instantiated this model to define our specific routing method. In addition, we addressed two difficult challenging problems: (i) the bootstraping (ii) the unsuccessful relevant peers search. Secondly, we are focalized on P2P systems over MANET. Due the nature of MANET, mobile P2P systems suffer from several constraints of wireless medium and energy-limited. Indeed, query routing methods proposed for P2P system over Internet cannot be applied. In this context, we proposed a context-aware integrated routing method for P2P file sharing systems over MANET. The different contributions are developed, validated and evaluated with the network simulators PeerSim and NS2

Le monde des communications par satellite est dominé par les systèmes de diffusion de la télévision. Cependant, des satellites de communication offrent aussi des services de téléphonie et de données. Ils sont regroupés dans les familles des systèmes fixes et mobiles et ciblent des marchés de niche. Dans cette thèse, nous avons la volonté d’étendre les scénarios d’utilisation de ces systèmes. Notre vision nous dicte que leur développement est lié à l’utilisation de réseaux hybrides mobiles satellite-terrestre. En effet, une utilisation complémentaire des deux segments permet de s’affranchir d’une concurrence trop féroce des réseaux de télécommunications terrestres. Pour cela, nous optons pour deux applications qui nous paraissent prometteuses : un réseau mobile LTE (Long Term Evolution) avec des stations de base qui possèdent un backhaul satellite et un réseau MANET (Mobile Ad-hoc NETwork) qui s’interconnecte à des réseaux extérieurs grâce à des liaisons satellite. Nous soulevons l’un des problèmes les plus contraignants du réseau mobile LTE avec des backhauls satellite : la gestion de la mobilité. L’analyse du standard nous a conduits à conclure quant à la nécessité d’optimiser les procédures du handover. Ceux qui nécessitent des modifications surviennent entre des stations de base qui n’utilisent pas le même backhaul satellite et entre une station de base avec un backhaul satellite vers une avec un backhaul terrestre. Deux points nous ont semblé importants : la phase de préparation et le mécanisme qui permet d’éviter les pertes. Nous proposons donc une nouvelle phase de préparation qui prend en compte le retard induit par la liaison satellite ainsi qu’une phase de préparation à double décision combinée avec une préparation de multiples stations de base. Nous tentons ainsi de maximiser les chances de réaliser un handover avec succès. Puis, nous avons imaginé un mécanisme qui permet à la fois d’éviter les pertes lors de l’exécution du handover et de sauvegarder les précieuses ressources du satellite. Les réseaux MANET associés à des liaisons satellite offrent des caractéristiques très intéressantes pour les communications d’urgence, telles que l’indépendance vis-à-vis des infrastructures terrestres susceptibles d’être endommagées par des catastrophes ainsi qu’un déploiement rapide pour une intervention sur le théâtre des opérations. Nous avons souhaité améliorer l’un des points cruciaux dans le cadre d’une hybridation : la sélection de la passerelle satellite. Nous avons donc développé un mécanisme qui prend en compte la charge sur les passerelles satellite ainsi que le phénomène d’oscillation de passerelle souvent négligé dans la littérature. Ces optimisations ont pour but de favoriser le développement de réseaux hybrides satellite terrestres en améliorant les performances de ces réseaux. L’avenir nous semble prometteur quant à l’utilisation de la technologie LTE avec un backhaul satellite pour lequel nous avons proposé une nouvelle gestion de la mobilité qui est primordiale pour son développement. / Satellite communications are leaded by television broadcasting. Yet, fixed and mobile satellite systems provide voice services as well as IP-based applications. In this thesis, we try to develop user scenarios in order to extend their targeted market. Our vision to reach this objective consists to use hybrid satellite and terrestrial mobile networks. This network design avoids a competition between both segments in which a satellite success is difficult to imagine. Furthermore, hybrid networks may draw benefits from both segments. Two promising scenarios have been selected. The first one consists in a mobile LTE network (Long Term Evolution) with base stations backhauled by satellite links whereas the second scenario is composed of a Mobile Ad-hoc Network (MANET) connected to external networks thanks to satellite systems. One of the main problems in the hybrid LTE scenario is caused by mobility procedures. As a consequence of the standard analysis, we have decided to optimize the mobility management in two cases: a handover between two base stations for which the backhaul is provided by two different satellite terminals and a handover from a base station with a satellite backhaul to one with a terrestrial backhaul. Two procedures have drawn our attention: the preparation phase and the loss avoidance mechanism during the execution phase. First of all, we design a new procedure for the preparation which takes into account the delay induced by the satellite link. This new phase is based on a twofold decision preparation associated with multiple preparations. This solution leads to an increase of handover success. The second optimization aims to avoid losses during the execution phase and, at the same time, save satellite resources. MANET and satellite hybridization leads to very interesting characteristics for public safety communications. Indeed, these networks are independent of terrestrial infrastructures that can be impaired or destroyed. Furthermore, they can be rapidly deployed in the theater of operation. Gateway selection is a crucial problem linked to hybrid MANET. Therefore, we have focused our work on this mechanism taking into account the measured load on the satellite links as well as an oftenneglected phenomenon, the gateway flapping. These optimizations tend to promote hybrid satellite and terrestrial networks improving their performance. A promising future is foreseen for the hybrid LTE technology and we have proposed a solution to a problem that may be very detrimental to its deployment.