Nos travaux de thèse ont pour objectif la conception, la mise en Suvre et l'évaluation d'architectures pour la mobilité et la qualité de service (QoS) dans des systèmes satellites DVB-S2/RCS. Ces systèmes peuvent constituer une solution alternative efficace aux réseaux terrestres dans des zones reculées à faible densité de population mais ils doivent pour cela offrir les mêmes services tout en tenant compte de leurs caractéristiques spécifiques, en particulier leur long délai de transmission qui peut s'avérer problématique dans le cadre d'applications multimédias interactives. Notre première contribution a donc été de développer une architecture de QoS adaptée à ce type d'applications, utilisant le modèle DiffServ et se basant essentiellement sur l'interaction entre l'architecture liée au protocole d'initiation de session SIP et différentes entités du système satellite. La QoS peut alors être configurée de façon précise au niveau des STs, par le biais de l'outil TC, en analysant les descripteurs de session SDP compris dans les messages SIP et en déduisant leurs caractéristiques (débit, gigue max, délai max, etc...) soit localement si elles sont connues, soit à partir d'un service Web que nous avons développé. Nous avons ensuite proposé et développé une solution de mobilité basée sur SIP, adaptée au système satellite ainsi qu'à la solution de QoS précédemment décrite. Les performances de cette solution ont alors été comparées, en termes de temps d'interruption et de consommation de ressources, avec celles obtenues par Mobile IPv6 et certaines de ses extensions, démontrant ainsi de réelles améliorations pour le cas des applications multimédias interactives. Enfin, notre dernière contribution a été de développer deux architectures couplant QoS et mobilité, une spécifiquement conçue pour les applications interactives et basée sur la combinaison de notre solution de mobilité SIP avec notre architecture de QoS SIP et une autre basée sur Mobile IPv6 ou FMI Pv6 et sur l'interaction d'un QoS Agent mobile avec les entités de QoS du système satellite. Ces architectures ont été évaluées et comparées sur la plateforme d'émulation PLATINE développée dans le cadre du projet SATSIX.

<p>Nowadays, VoIP is getting more and more popular. It helps company to reduce cost, extends service to remote area, produce more service opportunities, etc. Besides these advantages, VoIP also put forward security problems.</p><p>In this paper, we introduce the popular protocols in VoIP and their security mechanisms, by introducing threats to VoIP, we point out the vulnerabilities with the security mechanisms of each VoIP protocol, and give recommendation for each VoIP protocol. In the conclusion part, we evaluate the vulnerabilities of each protocol, and point out in the future, with better protocol architecture, enhanced security policies, VoIP will has a brighter future.</p>

This work presents a novel Peer to Peer (P2P) framework for Session Initiation Protocol (SIP) on Mobile Ad Hoc Network (MANET). SIP is a client-server model of computing which can introduce a single point of failure problem. P2P SIP addresses this problem by using a distributed implementation based on a P2P paradigm. However, both the traditional SIP and P2P SIP architectures are not suitable for MANETs because they are initially designed for infrastructured networks whose most nodes are static. We focus on distributed P2P resource lookup mechanisms for SIP which can tolerate failures resulting from the node mobility. Our target application is SIP-based multimedia communication in a rapidly deployable disaster emergency network. To achieve our goal, we provide four contributions as follows. The first contribution is a novel P2P lookup architecture based on a concept of P2P overlay network called a Structured Mesh Overlay Network (SMON). This overlay network enables P2P applications to perform fast resource lookups in the MANET environment. SMON utilizes a cross layer design based on the Distributed Hashing Table (DHT) and has direct access to OLSR routing information. Its cross layer design allows optimizing the overlay network performance during the change of network topology. The second contribution is a distributed SIP architecture on MANET providing SIP user location discovery in a P2P manner which tolerates single-point and multiple-point of failures. Our approach extends the traditional SIP user location discovery by utilizing DHT in SMON to distribute SIP object identifiers over SMON. It offers a constant time on SIP user discovery which results in a fast call setup time between two MANET users. From simulation and experiment results, we find that SIPMON provides the lowest call setup delay when compared to the existing broadcast-based approaches. The third contribution is an extended SIPMON supporting several participating MANETs connected to Internet. This extension (SIPMON+) provides seamless mobility support allowing a SIP user to roam from an ad hoc network to an infrastructured network such as Internet without interrupting an ongoing session. We propose a novel OLSR Overlay Network (OON), a single overlay network containing MANET nodes and some nodes on the Internet. These nodes can communicate using the same OLSR routing protocol. Therefore, SIPMON can be automatically extended without modifying SIPMON internal operations. Through our test-bed experiments, we prove that SIPMON+ has better performance in terms of call setup delay and handoff delay than MANET for Network Mobility (MANEMO). The fourth contribution is a proof-of-concept and a prototype of P2P multimedia communication based on SIPMON+ for post disaster recovery missions. We evaluate our prototype and MANEMO-based approaches through experimentation in real disaster situations (Vehicle to Infrastructure scenarios). We found that our prototype outperforms MANEMO-based approaches in terms of call setup delay, packet loss, and deployment time.

Les travaux décrits dans cette thèse s'articulent autour des architectures de communication en réseaux locaux et réseaux distants pour les applications de simul! ation distribuée interactive, particulièrement dans le cadre d! u projet Platsim. Nous avons traité dans un premier temps, les aspects gestion de la QoS pour les simulations distribuées basées sur les middlewares HLA et DDS en réseaux locaux, et ensuite nous avons étendu cette contribution avec DDS sur des réseaux grandes distances. La première contribution consiste à enrichir PlatSim par un modèle formel pour la gestion de la QoS que nous avons implémentée sur HLA pour combler les manques de QoS dont souffre ce middleware. Ensuite, nous avons proposé une architecture pour l'interconnexion des simulateurs distribués avec le middleware DDS. L'utilisation de DDS est intéressante pour la simplicité de son implémentation et ses performances de communication déjà prouvées sur des systèmes complexes. Dans la deuxième contribution, nous avons développé un algorithme de navigation à l'estime (dead-reckoning) pour l'anticipation du comportement des entités simulées. Cette approche permet d'émuler leur comportement lors de la déterm! ination de l'erreur maximale admissible satisfaisant les contraintes de la QoS requise, ce qui, en cas de défaillance du système de communication, permet d'estimer le comportement des objets simulés. Ensuite, nous avons présenté une proposition pour l'interconnexion des simulations distribuées DDS et cette approche de dead-reckoning, par deux mécanismes différents: dans un premier temps, nous avons montré qu'il est possible d'utiliser le service de routage DDS pour mettre en place un "pont-fédéré" DDS permettant d'interconnecter des domaines DDS différents dans un même domaine IP, et ensuite nous avons proposé un "Proxy DDS" qui permet d'interconnecter des simulations DDS situées dans des domaines DDS différents et des domaines IP hétérogènes. Enfin, nos deux dernières contributions con cernent l'étude et la mise en place d'une architecture de communication à grande distance à QoS garantie pour les simulations distribuées sur DDS. Tout d'abord, nous avons présenté! une architecture de signalisation de la QoS pour en se basant! sur l'u tilisation conjointe du protocole COPS et de la signalisation SIP. Ensuite, nous avons étendu des travaux réalisés au LAAS-CNRS dans le cadre du projet européen EuQoS. Nous avons alors utilisé des composants de cette architecture que nous avons adaptés pour fournir, à l'utilisateur final ou à l'administrateur de l'application, des interfaces simples lui permettant de demander le type de service requis pour son application sans avoir besoin de changer le protocole de signalisation.

Aujourd'hui le test de fabrication de circuits intégrés au niveau wafer s'appuie sur une technologie par contact entre l'équipement de test et les circuits à tester. Cette méthode souffre de plusieurs limitations telles que l'endommagement des plots de contact lorsque plusieurs tests sont necessaires en cours de fabrication du système. Pour pallier ces limitations, nous avons exploré une alternative de test basée sur communication sans fil. Pour cela une interface de test a été développée, cette interface doit être intégrée au sein de chaque dispositif à tester. Cette solution innovante entièrement développée au cours de ma thèse permet d'une part au testeur de diffuser simultanément les données de test vers tous les dispositifs du wafer, et d'autre part à chaque dispositif de retourner ses réponses vers le testeur. Cette interface a été développée pour permettre le test d'un dispositif en cours de fabrication (tous les éléments composant le système ne sont pas présent), et optimiser le temps de test de l'ensemble d'un wafer. Plusieurs campagnes de test sur des dispositifs réels nous ont permis de valider une solution au problème de l'alimentation des dispositifs sur le wafer. Cette solution s'appuie sur une distribution des alimentations par des rails insérées sur les lignes de découpage du wafer. Enfin, un prototype de notre interface de test sans fil a été réalisé sur une plateforme reconfigurable et nous a permis de valider son fonctionnement en testant un circuit du commerce.

ABSTRACT SIMULATION BASED INVESTIGATION OF AN IMPROVEMENT FOR FASTER SIP RE-REGISTRATION TANRIVERDi, Eda M.Sc., Department of Electrical and Electronics Engineering Supervisor: Prof. Dr. Semih BiLGEN July 2004, 78 pages In this thesis, the Session Initiation Protocol (SIP) is studied and an improvement for faster re-registration is proposed. This proposal, namely the &ldquo / registration &ndash / activation&rdquo / , is investigated with a simulation prepared using OPNET. The literature about wireless mobile networks and SIP mobility is reviewed. Conditions for an effective mobile SIP network simulation are designed using message sequence charts. The testbed in [1] formed by Dutta et. al. that has been used to observe SIP handover performance is simulated and validated. The mobile nodes, SIP Proxy v servers, DHCP servers and network topology are simulated on &ldquo / OPNET Modeler Radio&rdquo / . Once the simulation is proven to be valid, the &ldquo / registration &ndash / activation&rdquo / is implemented. Different simulation scenarios are set up and run, with different mobile node speeds and different numbers of mobile nodes. The results show that the re-registration delay is improved by applying the &ldquo / registration &ndash / activation&rdquo / but the percentage of improvement depends on the improvement in the database access delay in the SIP Proxy server.

High-performance networking (HPN) is of significance today in order to enable next-generation applications using wired and wireless networks. Some of the examples of HPN include low-latency industrial sensing, monitoring and automation using Wireless Sensor Networks (WSNs). HPN however requires protocol optimization at many layers of the open system interface (OSI) network model in order to meet the stringent performance constraints of the given applications. Furthermore, these protocols need to be impervious to denial of service (DoS) and distributed DoS (DDoS) attacks. Some of the key performance aspects of HPN are low point-to-point and end-to-end latency, high reliability of transmitted frames and performance predictability under various network load situations. This work focuses on two discrete issues in designing protocols for HPN applications. The first research issue looks at the Medium Access Control (MAC) layer of the OSI network model for designing of MAC protocols that provide low-latency and high reliability for point-to-point communication under a WSN. Existing standards in this area are governed by IEEE 802.15.4 specification which defines protocols for MAC and PHY layers for short-range, low bit-rate, and low-cost wireless networks. However, the IEEE 802.15.4 specification is inefficient in terms of latency and reliability performance and, as a result, is unable to meet the stringent operational requirements as defined by counterpart wired sensor networks. Work presented under current research issue describes new MAC protocols that are able to show low-latency transmission performance under strict timing constants for power limited WSNs. This enhancement of the MAC protocols is named extended GTS (XGTS) contained under extended CFP (ECFP) and is published under the IEEE's 802.15.4e standard. The second research issue focuses on the application layer of the OSI network model to design protocols that enhance the robustness of the text based protocols to various traffic inputs. The purpose of this is to increase the reliability of the given text based application layer protocol under a varied load. Session Initiation Protocol (SIP) is used as a case study and the work aims to build algorithms that ensure that SIP can continue to function under specific traffic conditions, which would otherwise deem the protocol useless due to DoS and DDoS attacks. Proposed algorithms investigate techniques that enhance the robustness of the SIP against parsing attacks without performing a deep parse of the protocol data unit (PDU). The desired effect of this is to reduce the time spent in parsing the SIP messages at a SIP router and as a result increase the number of SIP messages processed per unit time at a SIP router.

Resíduos produzidos em atividades industriais podem trazer danos significativos ao ambiente, principalmente quando estes não são degradáveis (ou são dificilmente degradáveis) por processos naturais. Polímeros sintéticos estão entre os principais resíduos descartados na natureza, permanecendo inertes por séculos e interferindo em processos ecológicos. Diante deste contexto, explorar o potencial biodegradável de plásticos e uma alternativa na substituição de embalagens descartáveis. Para a construção e otimização de materiais biodegradáveis, faz-se necessária a compreensão da ação da microbiota natural em processos de biodegradação natural. Neste trabalho, buscou-se compreender a dinâmica de microrganismos do filo Bacteroidetes no processo de biodegradação de blenda polimérica Poli (&#603;-caprolactona) / Amido/ Proteína Isolada de Soja (PCL/A/PIS), considerando solos e materiais plásticos distintos, como também a presença de genes notadamente associados a degradação biológica. Para tanto, partindo de amostras de DNA obtidas do solo ao longo do processo de biodegradação, foram utilizadas técnicas de PCR e PCR-DGGE (Reação de Polimerização em Cadeia - Eletroforese em Gel com Gradiente Desnaturante). Observou-se que: Bacteroidetes estão presentes em todos os momentos avaliados do processo de biodegradação da Blenda e do PCL; o solo Arenoso, onde a biodegradação e mais efetiva, apresenta comunidades com perfis bem delimitados, que se diferenciam na degradação da Blenda e do PCL; a dinâmica no solo Argiloso não exibe um padrão claro de influencia dos plásticos sobre a comunidade, apontando, porem para uma convergência de similaridade das comunidades sobre blenda e PCL no momento de maior atividade degradativa. Chitinophagaceae e uma família presente na biodegradação, sendo Chitinophaga pinensis uma das espécies presentes; genes exclusivos a esta espécie e outras da mesma família que codificam lipases e proteases, associados a degradação de polímeros pela literatura cientifica, estão presentes nas amostras de solo avaliadas, sendo possíveis atores na biodegradação dos plásticos. Bacteroidetes aparenta ser um filo importante em processos naturais de biodegradação de polímeros em solos, e explorar o potencial deste grupo e da família Chitinophagaceae pode oferecer subsídios para a construção de plásticos mais eficientes em sua biodegradação. / The human productive activity has brought significant damage to the environment, particularly by the disposal of non-degradable waste (or poorly degradable) by natural processes. Synthetic polymers are among the main materials discarded, remaining inert for centuries, causing damage to the natural wildlife or interfering with ecological processes. Given this context, the potential use of biodegradable plastics is an alternative, both for agriculture and for the replacement of disposable packaging. For the construction and optimization of biodegradable materials it is necessary to understand the action of natural microbial communities in the process. Microorganisms have predominant and diversified roles in the biodegradation process, with complex ecological relationships in their responses, either by their phylogenetic relationships or the enzymes used during the process. In this work, we sought to understand the dynamics of Bacteroidetes phylum in the biodegradation process of polymer blend poly (&#603;-caprolactone) / starch / Soy Protein Isolate (PCL/ A/ SPI), considering different soils and plastics, and also the presence of genes associated with biological degradation. Therefore, starting from DNA samples taken from the soil during the biodegradation process, PCR techniques and PCR-DGGE (Polymerization Chain Reaction - Denaturing Gradient Gel Electrophoresis) were used. It was observed that: the Phylum Bacteroidetes is present in all periods evaluated of the biodegradation process of Blend, PCL and even soils without the addition of plastics; the sandy soil, where the biodegradation is more effective, presents communities with well defined profiles that differ in the degradation of blends and PCL; the dynamics in clay soil does not show a clear pattern of plastics influence over the community, pointing to a convergence of communities similarity in blends and PCL over greater degradation activity. Chitinophagaceae is a family present in biodegradation, Chitinophaga pinensis being one of the species present; genes unique to this species and others of the same family encoding lipases and proteases, associated with the degradation of polymers reported in the scientific literature, are present in the evaluated soil samples, potentially acting on plastics biodegradation. Bacteroidetes appears to be an important phylum in natural processes of polymer biodegradation in soils, and to explore the potential of this taxon and of Chitinophagaceae family can shed light on the construction of more efficient biodegradable plastics.

IP Multimedia Subsystem (IMS) is the next generation of telecommunication systems. The system is based on an IP network and uses technologies from the Internet. The IMS system is designed to evolve from a telephone system into a general information and communication system. It is meant to include television, Video on Demand (VoD), interactive services etc, etc. It is designed to simplify the implementation of newservices in telecom networks. This report investigates security aspects of VoD services when merging an IP Television (IPTV) system with IMS. The investigation covers security functions in IMS, transitionsolutions for authentication of the Set-Top-Box (STB) in IMS, and identifies problems inthe integration of IPTV and IMS. The report concludes that IMS has good solid Authentication, Authorization, and Accounting (AAA) functions that will provide security and billing functionality. One problemis found in the media control between the STB and the streaming server. This interface lacked specification at the time of investigation, and some problems have been identified. These problems have to be solved before a system can be brought into service and beregarded as secure.

This diploma thesis researches the effect of yoga group exercising on children diagnosed with developmental coordination disorder. The theoretical part provides an overview of knowledge about the developmental coordination disorder, it mentions the issue with nomenclature and summarizes the options of treatment. It also deals with yoga, especially it's use as a form of therapy for wide range of diagnosis in adults as well as in children population. The aim of the practical part was to find out if there is any improvement in motor and other abilities after group exercising of yoga. Children were examined by Movement Assessment Battery for Children 2 and by selected subtests from Sensory Integration and Praxis test, specifically Postural Praxis, Bilateral Motor Coordination, Postrotary Nystagmus, Manual Form Perception and Localization of Tactile Stimuli. Parents of children filled Short Sensory Profile and Developmental Coordination Disorder Questionnaire. The study demonstrated improvement in MABC-2 test results, specifically in Aiming and Catching and Balance subtests. There was also significant improvement in these subtests of Sensory Integration and Praxis test: Postural Praxis, Bilateral Motor Coordination and Localization of Tactile Stimuli. Both questionnaires did not show any improvement.