123 research outputs found

    TV-Centric technologies to provide remote areas with two-way satellite broadband access

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    October 1-2, 2007, Rome, Italy TV-Centric Technologies To Provide Remote Areas With Two-Way Satellite Broadband Acces

    Smart PIN: performance and cost-oriented context-aware personal information network

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    The next generation of networks will involve interconnection of heterogeneous individual networks such as WPAN, WLAN, WMAN and Cellular network, adopting the IP as common infrastructural protocol and providing virtually always-connected network. Furthermore, there are many devices which enable easy acquisition and storage of information as pictures, movies, emails, etc. Therefore, the information overload and divergent content’s characteristics make it difficult for users to handle their data in manual way. Consequently, there is a need for personalised automatic services which would enable data exchange across heterogeneous network and devices. To support these personalised services, user centric approaches for data delivery across the heterogeneous network are also required. In this context, this thesis proposes Smart PIN - a novel performance and cost-oriented context-aware Personal Information Network. Smart PIN's architecture is detailed including its network, service and management components. Within the service component, two novel schemes for efficient delivery of context and content data are proposed: Multimedia Data Replication Scheme (MDRS) and Quality-oriented Algorithm for Multiple-source Multimedia Delivery (QAMMD). MDRS supports efficient data accessibility among distributed devices using data replication which is based on a utility function and a minimum data set. QAMMD employs a buffer underflow avoidance scheme for streaming, which achieves high multimedia quality without content adaptation to network conditions. Simulation models for MDRS and QAMMD were built which are based on various heterogeneous network scenarios. Additionally a multiple-source streaming based on QAMMS was implemented as a prototype and tested in an emulated network environment. Comparative tests show that MDRS and QAMMD perform significantly better than other approaches

    Survey on QoE/QoS Correlation Models for Video Streaming over Vehicular Ad-hoc Networks

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    Vehicular Ad-hoc Networks (VANETs) are a new emerging technology which has attracted enormous interest over the last few years. It enables vehicles to communicate with each other and with roadside infrastructures for many applications. One of the promising applications is multimedia services for traffic safety or infotainment. The video service requires a good quality to satisfy the end-user known as the Quality of Experience (QoE). Several models have been suggested in the literature to measure or predict this metric. In this paper, we present an overview of interesting researches, which propose QoE models for video streaming over VANETs. The limits and deficiencies of these models are identified, which shed light on the challenges and real problems to overcome in the future

    Reputation-based network selection solution for improved video delivery quality in heterogeneous wireless network environments

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    The continuous innovations and advances in both high-end mobile devices and wireless communication technologies have increased the users demand and expectations for anywhere, anytime, any device high quality multimedia applications provisioning. Moreover, the heterogeneity of the wireless network environment offers the possibility to the mobile user to select between several available radio access network technologies. However, selecting the network that enables the best user perceived video quality is not trivial given that in general the network characteristics vary widely not only in time but also depending on the user location within each network. In this context, this paper proposes a user location-aware reputation-based network selection solution which aims at improving the video delivery in a heterogeneous wireless network environment by selecting the best value network. Network performance is regularly monitored and evaluated by the currently connected users in different areas of each individual network. Based on the existing network performance-related information and mobile user location and speed, the network that offers the best support for video delivery along the userñ€ℱs path is selected as the target network and the handover is triggered. The simulation results show that the proposed solution improves the video delivery quality in comparison with the case when a classic network selection mechanism was employed

    Context-awareness for ubiquitous media service delivery in next generation networks

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    Les rĂ©centes avancĂ©es technologiques permettent dĂ©sormais la fabrication de terminaux mobiles de plus en plus compacts et dotĂ©s de plusieurs interfaces rĂ©seaux. Le nouveau modĂšle de consommation de mĂ©dias se rĂ©sume par le concept "Anytime, Anywhere, Any Device" et impose donc de nouvelles exigences en termes de dĂ©ploiement de services ubiquitaires. Cependant la conception et le developpement de rĂ©seaux ubiquitaires et convergents de nouvelles gĂ©nĂ©rations soulĂšvent un certain nombre de dĂ©fis techniques. Les standards actuels ainsi que les solutions commerciales pourraient ĂȘtre affectĂ©s par le manque de considĂ©ration du contexte utilisateur. Le ressenti de l'utilisateur concernant certains services multimĂ©dia tels que la VoIP et l'IPTV dĂ©pend fortement des capacitĂ©s du terminal et des conditions du rĂ©seau d'accĂšs. Cela incite les rĂ©seaux de nouvelles gĂ©nĂ©rations Ă  fournir des services ubiquitaires adaptĂ©s Ă  l'environnement de l'utilisateur optimisant par la mĂȘme occasion ses resources. L'IP Multimedia Subsystem (IMS) est une architecture de nouvelle gĂ©nĂ©ration qui centralise l'accĂšs aux services et permet la convergence des rĂ©seaux fixe/mobile. NĂ©anmoins, l'Ă©volution de l'IMS est nĂ©cessaire sur les points suivants :- l'introduction de la sensibilitĂ© au contexte utilisateur et de la PQoS (Perceived QoS) : L'architecture IMS ne prend pas en compte l'environnement de l'utilisateur, ses prĂ©fĂ©rences et ne dispose pas d'un mĂ©chanisme de gestion de PQOS. Pour s'assurer de la qualitĂ© fournit Ă  l'utilisateur final, des informations sur l'environnement de l'utilisateur ainsi que ses prĂ©fĂ©rences doivent transiter en cƓur de rĂ©seau afin d'y ĂȘtre analysĂ©s. Ce traitement aboutit au lancement du service qui sera adaptĂ© et optimisĂ© aux conditions observĂ©es. De plus pour le service d'IPTV, les caractĂ©ristiques spatio-temporelles de la vidĂ©o influent de maniĂšre importante sur la PQoS observĂ©e cĂŽtĂ© utilisateur. L'adaptation des services multimĂ©dias en fonction de l'Ă©volution du contexte utilisateur et de la nature de la vidĂ©o diffusĂ©e assure une qualitĂ© d'expĂ©rience Ă  l'utilisateur et optimise par la mĂȘme occasion l'utilisation des ressources en cƓur de rĂ©seau.- une solution de mobilitĂ© efficace pour les services conversationnels tels que la VoIP : Les derniĂšres publications 3GPP fournissent deux solutions de mobilitĂ©: le LTE proposeMIP comme solution de mobilitĂ© alors que l'IMS dĂ©finit une mobilitĂ© basĂ©e sur le protocoleapplicatif SIP. Ces standards dĂ©finissent le systĂšme de signalisation mais ne s'avancent pas sur la gestion du flux mĂ©dia lors du changement d'interface rĂ©seau. La deuxiĂšme section introduit une Ă©tude comparative dĂ©taillĂ©e des solutions de mobilitĂ© dans les NGNs.Notre premiĂšre contribution est la spĂ©cification de l'architecture globale de notre plateforme IMS sensible au contexte utilisateur rĂ©alisĂ©e au sein du projet EuropĂ©en ADAMANTIUM. Nous dĂ©taillons tout d'abord le serveur MCMS intelligent placĂ© dans la couche application de l'IMS. Cet Ă©lĂ©ment rĂ©colte les informations de qualitĂ© de services Ă  diffĂ©rents Ă©quipements rĂ©seaux et prend la dĂ©cision d'une action sur l'un de ces Ă©quipements. Ensuite nous dĂ©finissons un profil utilisateur permettant de dĂ©crire son environnement et de le diffuser en coeur de rĂ©seau. Une Ă©tude sur la prĂ©diction de satisfaction utilisateur en fonction des paramĂštres spatio-temporels de la vidĂ©o a Ă©tĂ© rĂ©alisĂ©e afin de connaĂźtre le dĂ©bit idĂ©al pour une PQoS dĂ©sirĂ©e.Notre deuxiĂšme contribution est l'introduction d'une solution de mobilitĂ© adaptĂ©e aux services conversationnels (VoIP) tenant compte du contexte utilisateur. Notre solution s'intĂšgre Ă  l'architecture IMS existante de façon transparente et permet de rĂ©duire le temps de latence du handover. Notre solution duplique les paquets de VoIP sur les deux interfaces actives pendant le temps de la transition. ParallĂšlement, un nouvel algorithme de gestion de mĂ©moire tampon amĂ©liore la qualitĂ© d'expĂ©rience pour le service de VoIP.The latest advances in technology have already defied Moore s law. Thanks to research and industry, hand-held devices are composed of high processing embedded systems enabling the consumption of high quality services. Furthermore, recent trends in communication drive users to consume media Anytime, Anywhere on Any Device via multiple wired and wireless network interfaces. This creates new demands for ubiquitous and high quality service provision management. However, defining and developing the next generation of ubiquitous and converged networks raise a number of challenges. Currently, telecommunication standards do not consider context-awareness aspects for network management and service provisioning. The experience felt by the end-user consuming for instance Voice over IP (VoIP) or Internet Protocol TeleVision (IPTV) services varies depending mainly on user preferences, device context and network resources. It is commonly held that Next Generation Network (NGN) should deliver personalized and effective ubiquitous services to the end user s Mobile Node (MN) while optimizing the network resources at the network operator side. IP Multimedia Subsystem (IMS) is a standardized NGN framework that unifies service access and allows fixed/mobile network convergence. Nevertheless IMS technology still suffers from a number of confining factors that are addressed in this thesis; amongst them are two main issues :The lack of context-awareness and Perceived-QoS (PQoS):-The existing IMS infrastructure does not take into account the environment of the user ,his preferences , and does not provide any PQoS aware management mechanism within its service provisioning control system. In order to ensure that the service satisfies the consumer, this information need to be sent to the core network for analysis. In order to maximize the end-user satisfaction while optimizing network resources, the combination of a user-centric network management and adaptive services according to the user s environment and network conditions are considered. Moreover, video content dynamics are also considered as they significantly impact on the deduced perceptual quality of IPTV services. -The lack of efficient mobility mechanism for conversational services like VoIP :The latest releases of Third Generation Partnership Project (3GPP) provide two types of mobility solutions. Long-Term Evolution (LTE) uses Mobile IP (MIP) and IMS uses Session Initiation Protocol (SIP) mobility. These standards are focusing on signaling but none of them define how the media should be scheduled in multi-homed devices. The second section introduces a detailed study of existing mobility solutions in NGNs. Our first contribution is the specification of the global context-aware IMS architecture proposed within the European project ADAptative Management of mediA distributioN based on saTisfaction orIented User Modeling (ADAMANTIUM). We introduce the innovative Multimedia Content Management System (MCMS) located in the application layer of IMS. This server combines the collected monitoring information from different network equipments with the data of the user profile and takes adaptation actions if necessary. Then, we introduce the User Profile (UP) management within the User Equipment (UE) describing the end-user s context and facilitating the diffusion of the end-user environment towards the IMS core network. In order to optimize the network usage, a PQoS prediction mechanism gives the optimal video bit-rate according to the video content dynamics. Our second contribution in this thesis is an efficient mobility solution for VoIP service within IMS using and taking advantage of user context. Our solution uses packet duplication on both active interfaces during handover process. In order to leverage this mechanism, a new jitter buffer algorithm is proposed at MN side to improve the user s quality of experience. Furthermore, our mobility solution integrates easily to the existing IMS platform.BORDEAUX1-Bib.electronique (335229901) / SudocSudocFranceF

    Integrated control platform for converged optical and wireless networks

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