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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Contrôle de la mobilité dans un réseau d'opérateur convergé fixe-mobile / Mobility management in a converged fixed-mobile operator's network

Eido, Souheir 12 July 2017 (has links)
Les réseaux fixes et mobiles font face à une croissance dramatique du trafic de données, qui est principalement due à la distribution de contenus vidéo. Les opérateurs Télécoms envisagent donc de décentraliser la distribution de contenus dans les futures architectures convergées fixe-mobile (FMC). Cette décentralisation, conjointement au déploiement d'un cœur de réseau mobile distribué, sera un élément majeur des futurs réseaux 5G. L'approche SIPTO définie par 3GPP permet déjà le délestage sur le réseau fixe du trafic mobile, et pourra donc être utilisée en 5G. SIPTO s'appuie sur la distribution des passerelles de données (PGW) qui permet ainsi de décharger le cœur du réseau mobile actuel. Cependant, dans certains cas de mobilité des usagers, SIPTO ne supporte pas la continuité de session, quand il est nécessaire de changer de PGW, donc de modifier l'adresse IP du terminal. Cette thèse commence par quantifier le gain apporté par le délestage du trafic mobile en termes de capacité requise pour différentes portions du réseau. Un état de l'art des différentes solutions de délestage du trafic de données mobiles est fourni, démontrant qu'aucune des solutions existantes ne supporte la continuité de service pour les sessions de longue durée. C'est pourquoi, cette thèse propose des solutions pour supporter une mobilité transparente ; ces solutions s'appuient à la fois sur SIPTO et sur le protocole MultiPath TCP (MPTCP). Les protocoles du 3GPP sont inchangés car la continuité est maintenue par les extrémités. Enfin, ces solutions sont appliquées aux différentes implémentations d'architectures FMC envisagées à ce jour. / Fixed and mobile networks are currently experiencing a dramatic growth in terms of data traffic, mainly driven by video content distribution. Telecoms operators are thus considering de-centralizing content distribution architecture for future Fixed and Mobile Converged (FMC) network architectures. This decentralization, together with a distributed mobile EPC, would be used for future 5G networks. Mobile data offloading, in particular SIPTO approaches, already represent a good implementation model for 5G network as it allows the use of distributed IP edges to offload Selected IP traffic off the currently centralized mobile core network. However, in some cases, SIPTO does not support session continuity during users' mobility. This is due to the fact that user's mobility may imply packet gateway (PGW) relocation and thus a modification of the UE's IP address.This PhD thesis first quantifies the gain, in terms of bandwidth demands on various network portions, brought by the generalized use of mobile traffic offloading. A state of art of existing mobile data offloading solutions is presented, showing that none of the existing solutions solve the problem of session continuity for long-lived sessions. This is why, in the context of future FMC mobile network architectures, the PhD thesis proposes solutions to provide seamless mobility for users relying on SIPTO with the help of Multipath TCP (MPTCP). 3GPP standards are not modified, as session continuity is ensured by end-points. Lastly, the proposed solutions are mapped on different architecture options considered for future FMC networks.
42

Dissémination de données dans les réseaux véhiculaires / Data dissemination in vehicular networks

Idir, Lilia 21 October 2015 (has links)
Le nombre de véhicules circulant sur les routes dans le monde est passé de 500 millions en 1986 à 1 milliard de véhicules en 2010. Un tel réseau routier immense a apporté un certain confort à de nombreux conducteurs mais d'un autre coté il a représenté environs 1,24 millions d'accidents en 2010. Avec ces chiffres vient l'augmentation du niveau des émissions de CO2 et des milliards d'heures perdues dans les embouteillages. Avec le progrès et le développement des technologies sans fil ces dernières années, les réseaux véhiculaires ont rapidement évolués. Beaucoup de constructeurs automobiles et de pays ont intégré et imaginé différentes applications dans les réseaux véhiculaires : des applications de sécurité routières, d'autres pour l'information sur le trafic, ainsi que des applications de divertissement. Cette dernière catégorie d'applications se distingue des autres par la quantité et le volume de données échangées, et constitue un réel problème dû à la nature des communications sans fil véhiculaires. Dans cette thèse, nous traitons le problème de la dissémination d'information dans les systèmes véhiculaires distribués. Notre objectif principal est de proposer des solutions pratiques et réalisables pour diffuser les données dans des environnements véhiculaires réalistes. Le concept de la diffusion des données est large et significatif. Dans ce contexte, nous nous référons à la diffusion de données chaque fois qu'il y a une certaine quantité de données qui doit être répartie sur un réseau distribué sans fil. Les données sont envoyées vers plusieurs destinations (même à tous les nœuds du réseau dans certain cas) qui sont intéressés pour récupérer la totalité ou une partie des informations générées. A titre d'exemples, nous pouvons considérer les applications de partage de fichiers, la diffusion de fichiers multimédia et ainsi de suite. Nous abordons dans cette thèse le problème de dissémination de données dans les réseaux véhiculaires, plus précisément la dissémination de grands volumes de données tel que le contenu multimédia. Avec l'évolution au cours de ces dernières années des réseaux véhiculaires notamment grâce au support de nombreux constructeurs automobiles (e.x. Toyota, Nissan, BMW, Ford, etc.), la quantité de données échangée a augmenté de manière exponentielle au fil des années. Malheureusement malgré l'avancement des technologies de communications sans fil, l'échange de grands volumes de données dans des réseaux véhiculaires reste un réel défi, à cause des caractéristiques de communications sans fil et celles spécifiques aux réseaux véhiculaires. / The number of vehicles on the roads in the world increased from 500 million in 1986 to 1 billion vehicles in 2010. Such a huge road network has brought some comfort to many drivers but on the other hand it represented around 1.24 million accidents in 2010. With the progress and development of wireless technologies these recent years, vehicular networks quickly evolved. Many car manufacturers and countries have built and imagined different applications in vehicular networks: road safety applications, others for traffic information, and entertainment applications. This last category of applications is distinguished from others by the quantity and volume of exchanged data, and represents a real problem due to the lossy nature of vehicular communications. In this thesis, we address the problem of data dissemination in distributed vehicular systems. Our main objective is to provide practical and workable solutions to disseminate data in realistic vehicular environments. The concept of data dissemination is large and significant. In this context, we call data dissemination each time there is a certain amount of data which must be distributed on in wireless network. The data is sent to multiple destinations who are interested to recover all or part of the information. As examples, we can consider the file sharing applications, streaming multimedia files and so on. We discuss in this thesis the data dissemination problem in vehicular networks, specifically the dissemination of large volumes of data such as content distribution. With the evolution in recent years of vehicular networks thanks to many car manufacturers support (eg Toyota, Nissan, BMW, Ford, etc.), the amount of exchanged data has increased exponentially over the years. Unfortunately, despite the advancement of wireless communications technologies, exchange large volumes of data in vehicular networks remains a challenge because of wireless communications features and those specific to vehicular networks.
43

Detekce P2P sítí / Detection of P2P Networks

Březina, Matej January 2008 (has links)
This document deals with design, implementation and testing of software system for detecting p2p (peer-to-peer) networks based on combination of BPF prefiltering and POSIX regular expressions packet payload matching with known p2p protocol communications. The proposed detection system includes a database with some rules of most effuse p2p protocols in format resembling to definitions for L7-filter classifier. The application is implemented in C, runs in userspace and is targeted to all POSIX compatible platforms. The combination of detector with user attached QoS controlling is complete solution for traffic reduction of common p2p protocols.
44

Mobile Opportunistic Services for Experience Sharing : Via a NetInf Android Application

Moradinia, Pourya, Sakhi, Imal January 2014 (has links)
Information-Centric Networking (ICN) is a new research area concerning creating a new network architecture that would be more suitable for both current and the future's network. The MOSES (Mobile Opportunistic Services for Experience Sharing) project is part of this development. The project works with the development and demonstration of the Network of Information (NetInf) protocol, which is an implementation of the ICN concept. This Master’s thesis project is part of the MOSES project and aims to assist the MOSES project with the demonstration of a mobile opportunistic sharing concept based on the NetInf protocol. Demonstrating the MOSES concept in practice requires deep understanding of networking, localization, transport, and dissemination of digital content in an ad hoc network. This implementation requires an analysis of the previous work, development of new functionalities, and finally an analysis of a series of controlled experiments. This Master’s thesis project has designed, implemented, and evaluated an Android application within the MOSES framework by using the previously developed NetInf Android library. This prototype is used to demonstrate how mobile Android users can opportunistically share and disseminate content based on their location using the MOSES/ICN concept. The functionality and efficiency of the prototype Android application built during this thesis project has been analyzed and evaluated by conducting a series of controlled experiments under the supervision of MOSES researchers. The results of these controlled experiments has provided insight for MOSES researchers as well as explored the concept of using ICN (NetInf) for opportunistic content distribution. The experiment results aim at assisting MOSES researchers to extend and further develop the prototype application and the involved algorithms to create a fully functional mobile application for experience sharing services tailored to large-scale events. / Information-Centric Networking (ICN) är ett nytt forskningsområde för att bygga en ny nätverksarkitektur mer passande för dagens och framtida nätverk. MOSES projektet är en del av denna utveckling och arbetar med utveckling och demonstration av Network of Information (NetInf) protokollet, som är en implementering av ICN konceptet. Detta examensarbete är en del av MOSES (Mobile Opportunistic Services for Experience Sharing) projektet som syftar till att bistå MOSES projektet med demonstrationen av "mobile opportunistic sharing" konceptet som bygger på NetInf protokollet. Att demonstrera MOSES konceptet i praktiken krävs djupt förståelse om nätverk, lokalisering, transport och spridning av digitalt data i en "ad hoc" och infrastruktur miljö. Genomförandet av denna implementering kräver en analys av tidigare arbete, utveckling av nya funktioner och slutligen analys av genomförda experiment och resultaten. Detta examensarbete har utformat, genomfört och utvärderat en Android applikation inom ramen för MOSES med hjälp av tidigare utvecklat NetInf Android bibliotek. Denna prototyp används för att visa hur mobila Android användare opportunistiskt kan dela och sprida innehåll baserat på deras plats med hjälp av MOSES/ICN konceptet. Funktionaliteten och effektiviteten av prototypen byggd under detta examensarbete har analyserats och utvärderats genom att utföra en serie kontrollerade experiment under ledning av MOSES forskare. Resultaten av dessa kontrollerade experiment har gett insikt åt MOSES forskare samt utforskat konceptet att använda ICN (NetInf) för opportunistisk distribution av innehåll. Experimentens resultat syftar till att hjälpa MOSES forskare att utöka och vidareutveckla prototypen och de involverade algoritmer för att skapa en fullt fungerande mobil applikation för "experience sharing services" anpassad för stora evenemang.
45

Arquitetura de IPTV com suporte à apresentação deslocada no tempo baseada em distribuição peer-to-peer. / IPTV architecture with time-shift support based on peer-to-peer distribution.

Gallo, Diego Sanchez 11 March 2009 (has links)
Com o aumento da concorrência sofrido pelas operadoras de telecomunicações frente à entrada de diversas empresas de outros ramos no mercado de comunicação, como, por exemplo, os Provedores de Serviço de Internet (ISPs - Internet Service Providers) através da oferta de serviços de voz sobre IP, tais operadoras viram-se obrigadas a diversificar sua oferta de serviços para gerar novas fontes de receita. Por possuírem ampla infra-estrutura instalada, as operadoras de telecomunicações passaram a oferecer, também, serviço de TV aos usuários, através de suas redes (convergentes) de telefonia e dados já existentes, o chamado IPTV. O objetivo deste trabalho foi possibilitar, neste cenário, que estas empresas consigam oferecer, além dos serviços convencionais de TV (e.g., transmissões lineares dos conteúdos nos canais de TV), serviços diferenciados empregando-se a mesma infra-estrutura. O foco deste trabalho é a oferta do serviço de apresentação deslocada no tempo dos conteúdos transmitidos linearmente nos canais de TV, sem a necessidade de configuração prévia por parte do usuário. Desta maneira, dá-se maior flexibilidade ao usuário, possibilitando-o assistir aos conteúdos que lhe interessam, no horário mais conveniente, sem ter que se preocupar com isso antecipadamente (i.e., sem a necessidade de configurar algum equipamento para gravar o conteúdo ou saber antecipadamente quais programas lhe interessam). Para isso foram pesquisadas e analisadas tanto tecnologias de transmissão e distribuição de conteúdos, como também o paradigma peer-to-peer, muito utilizado atualmente no compartilhamento de arquivos na Internet. A partir daí, foi concebida uma arquitetura capaz de oferecer tanto o serviço tradicional de transmissão linear de TV, quanto de apresentar vídeos deslocados no tempo (i.e., vídeos cuja transmissão linear já foi iniciada ou até concluída, a partir de qualquer posição já transmitida), combinando-se técnicas de multidifusão de dados, armazenamento distribuído e protocolos peer-to-peer. Desta maneira, obteve-se uma solução eficiente, utilizando-se os recursos disponíveis em todo o sistema, incluindo recursos ociosos dos usuários finais, para auxiliar no armazenamento e distribuição dos conteúdos deslocados no tempo. Finalmente, um protótipo foi desenvolvido como prova de conceito da arquitetura proposta neste trabalho, e, juntamente com os testes realizados, comprovam a viabilidade de se utilizar redes P2P para a distribuição dos conteúdos para a apresentação deslocada no tempo. / Telecommunication companies are suffering from the increasing offer of cheap and reliable voice over IP services, being forced to diversify their services looking for new revenue possibilities. Since these companies have a vast infrastructure, they are now providing TV services through the same telephony and data infrastructure, using their IP networks to offer IPTV. The goal of the present work is to allow, in this scenario, that such companies offer, additionally to the traditional TV services (e.g., the linear transmissions of the TV channels), differentiated services through the same infrastructure. The focus of the present work is, therefore, the offering of the time-shift service, allowing users to watch linear transmitted contents, time-shifted, without the need for any in-advance configuration. This approach gives more flexibility to the users, allowing them to choose the most appropriate time to watch some content without having to specify their interests in advance (i.e., without configuring some equipment to record the content or knowing in advance which programs will interest themselves). To achieve this goal, technologies for content transmission and distribution, as well as the peer-to-peer paradigm for file sharing were studied, resulting in the development of an architecture capable of offering the traditional linear transmissions service as well as the possibility of time-shift, combining multicast, distributed caching and peer-to-peer technologies. Accordingly, an efficient solution was envisioned, making use of all available resources in the system, including idle resources in the user equipments, to help in the caching and distribution of the time-shifted contents. Finally, a prototype was developed as a proof-of-concept for the designed architecture, which together with the performed tests, shows the viability of utilizing P2P networks in the distribution of time-shifted contents.
46

Arquitetura de IPTV com suporte à apresentação deslocada no tempo baseada em distribuição peer-to-peer. / IPTV architecture with time-shift support based on peer-to-peer distribution.

Diego Sanchez Gallo 11 March 2009 (has links)
Com o aumento da concorrência sofrido pelas operadoras de telecomunicações frente à entrada de diversas empresas de outros ramos no mercado de comunicação, como, por exemplo, os Provedores de Serviço de Internet (ISPs - Internet Service Providers) através da oferta de serviços de voz sobre IP, tais operadoras viram-se obrigadas a diversificar sua oferta de serviços para gerar novas fontes de receita. Por possuírem ampla infra-estrutura instalada, as operadoras de telecomunicações passaram a oferecer, também, serviço de TV aos usuários, através de suas redes (convergentes) de telefonia e dados já existentes, o chamado IPTV. O objetivo deste trabalho foi possibilitar, neste cenário, que estas empresas consigam oferecer, além dos serviços convencionais de TV (e.g., transmissões lineares dos conteúdos nos canais de TV), serviços diferenciados empregando-se a mesma infra-estrutura. O foco deste trabalho é a oferta do serviço de apresentação deslocada no tempo dos conteúdos transmitidos linearmente nos canais de TV, sem a necessidade de configuração prévia por parte do usuário. Desta maneira, dá-se maior flexibilidade ao usuário, possibilitando-o assistir aos conteúdos que lhe interessam, no horário mais conveniente, sem ter que se preocupar com isso antecipadamente (i.e., sem a necessidade de configurar algum equipamento para gravar o conteúdo ou saber antecipadamente quais programas lhe interessam). Para isso foram pesquisadas e analisadas tanto tecnologias de transmissão e distribuição de conteúdos, como também o paradigma peer-to-peer, muito utilizado atualmente no compartilhamento de arquivos na Internet. A partir daí, foi concebida uma arquitetura capaz de oferecer tanto o serviço tradicional de transmissão linear de TV, quanto de apresentar vídeos deslocados no tempo (i.e., vídeos cuja transmissão linear já foi iniciada ou até concluída, a partir de qualquer posição já transmitida), combinando-se técnicas de multidifusão de dados, armazenamento distribuído e protocolos peer-to-peer. Desta maneira, obteve-se uma solução eficiente, utilizando-se os recursos disponíveis em todo o sistema, incluindo recursos ociosos dos usuários finais, para auxiliar no armazenamento e distribuição dos conteúdos deslocados no tempo. Finalmente, um protótipo foi desenvolvido como prova de conceito da arquitetura proposta neste trabalho, e, juntamente com os testes realizados, comprovam a viabilidade de se utilizar redes P2P para a distribuição dos conteúdos para a apresentação deslocada no tempo. / Telecommunication companies are suffering from the increasing offer of cheap and reliable voice over IP services, being forced to diversify their services looking for new revenue possibilities. Since these companies have a vast infrastructure, they are now providing TV services through the same telephony and data infrastructure, using their IP networks to offer IPTV. The goal of the present work is to allow, in this scenario, that such companies offer, additionally to the traditional TV services (e.g., the linear transmissions of the TV channels), differentiated services through the same infrastructure. The focus of the present work is, therefore, the offering of the time-shift service, allowing users to watch linear transmitted contents, time-shifted, without the need for any in-advance configuration. This approach gives more flexibility to the users, allowing them to choose the most appropriate time to watch some content without having to specify their interests in advance (i.e., without configuring some equipment to record the content or knowing in advance which programs will interest themselves). To achieve this goal, technologies for content transmission and distribution, as well as the peer-to-peer paradigm for file sharing were studied, resulting in the development of an architecture capable of offering the traditional linear transmissions service as well as the possibility of time-shift, combining multicast, distributed caching and peer-to-peer technologies. Accordingly, an efficient solution was envisioned, making use of all available resources in the system, including idle resources in the user equipments, to help in the caching and distribution of the time-shifted contents. Finally, a prototype was developed as a proof-of-concept for the designed architecture, which together with the performed tests, shows the viability of utilizing P2P networks in the distribution of time-shifted contents.
47

Content Distribution in Social Groups

Aggarwal, Saurabh January 2014 (has links) (PDF)
We study Social Groups consisting of self-interested inter-connected nodes looking for common content. We can observe Social Groups in various socio-technological networks, such as Cellular Network assisted Device-to-Device communications, Cloud assisted Peer-to-Peer Networks, hybrid Peer-to-Peer Content Distribution Networks and Direct Connect Networks. Each node wants to acquire a universe of segments at least cost. Nodes can either access an expensive link to the content distributor for downloading data segments, or use the well-connected low cost inter-node network for exchanging segments among themselves. Activation of an inter-node link requires cooperation among the participating nodes and reduces the cost of downloading for the nodes. However, due to uploading costs, Non-Reciprocating Nodes are reluctant to upload segments, in spite of their interest in downloading segments from others. We define the Give-and-Take (GT) criterion, which prohibits non-reciprocating behaviour in Social Groups for all nodes at all instants. In the “Full Exchange” case studied, two nodes can exchange copies of their entire segment sets, if each node gains at least one new segment from the other. Incorporating the GT criterion in the Social Group, we study the problem of downloading the universe at least cost, from the perspective of a new node having no data segments. We analyze this NP-hard problem, and propose algorithms for choosing the initial segments to be downloaded from the content distributor and the sequence of nodes for exchange. We compare the performance of these algorithms with a few existing P2P downloading strategies in terms of cost and running time. In the second problem, we attempt to reduce the load on the content distributor by choosing a schedule of inter-node link activations such that the number of nodes with the universe is maximized. Link activation decisions are taken by a central entity, the facilitator, for achieving the social optimum. We present the asymptotically optimal Randomized algorithm. We also present other algorithms, such as the Greedy Links algorithm and the Polygon algorithm, which are optimal under special scenarios of interest. We compare the performances of all proposed algorithms with the optimal value of the objective. We observe that computationally intensive algorithms exhibit better performance. Further, we consider the problem of decentralized scheduling of links. The decisions of link activations are made by the participating nodes in a distributed manner. While conforming to the GT criterion for inter-node exchanges, each node's objective is to maximize its utility. Each node tries to find a pairing partner by preferentially exploring nodes for link formation. Unpaired nodes choose to download a segment using the expensive link with Segment Aggressiveness Probability (SAP). We present linear complexity decentralized algorithms for nodes to choose their best strategy. We present a decentralized randomized algorithm that works in the absence of the facilitator and performs close to optimal for large number of nodes. We define the Price of Choice to benchmark performance of Social Groups (consisting of non-aggressive nodes) with the optimal. We evaluate the performance of various algorithms and characterize the behavioural regime that will yield best results for node and Social Group as well.

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