366 research outputs found

    Quality of service differentiation for multimedia delivery in wireless LANs

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    Delivering multimedia content to heterogeneous devices over a variable networking environment while maintaining high quality levels involves many technical challenges. The research reported in this thesis presents a solution for Quality of Service (QoS)-based service differentiation when delivering multimedia content over the wireless LANs. This thesis has three major contributions outlined below: 1. A Model-based Bandwidth Estimation algorithm (MBE), which estimates the available bandwidth based on novel TCP and UDP throughput models over IEEE 802.11 WLANs. MBE has been modelled, implemented, and tested through simulations and real life testing. In comparison with other bandwidth estimation techniques, MBE shows better performance in terms of error rate, overhead, and loss. 2. An intelligent Prioritized Adaptive Scheme (iPAS), which provides QoS service differentiation for multimedia delivery in wireless networks. iPAS assigns dynamic priorities to various streams and determines their bandwidth share by employing a probabilistic approach-which makes use of stereotypes. The total bandwidth to be allocated is estimated using MBE. The priority level of individual stream is variable and dependent on stream-related characteristics and delivery QoS parameters. iPAS can be deployed seamlessly over the original IEEE 802.11 protocols and can be included in the IEEE 802.21 framework in order to optimize the control signal communication. iPAS has been modelled, implemented, and evaluated via simulations. The results demonstrate that iPAS achieves better performance than the equal channel access mechanism over IEEE 802.11 DCF and a service differentiation scheme on top of IEEE 802.11e EDCA, in terms of fairness, throughput, delay, loss, and estimated PSNR. Additionally, both objective and subjective video quality assessment have been performed using a prototype system. 3. A QoS-based Downlink/Uplink Fairness Scheme, which uses the stereotypes-based structure to balance the QoS parameters (i.e. throughput, delay, and loss) between downlink and uplink VoIP traffic. The proposed scheme has been modelled and tested through simulations. The results show that, in comparison with other downlink/uplink fairness-oriented solutions, the proposed scheme performs better in terms of VoIP capacity and fairness level between downlink and uplink traffic

    Ubiquitous robust communications for emergency response using multi-operator heterogeneous networks

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    A number of disasters in various places of the planet have caused an extensive loss of lives, severe damages to properties and the environment, as well as a tremendous shock to the survivors. For relief and mitigation operations, emergency responders are immediately dispatched to the disaster areas. Ubiquitous and robust communications during the emergency response operations are of paramount importance. Nevertheless, various reports have highlighted that after many devastating events, the current technologies used, failed to support the mission critical communications, resulting in further loss of lives. Inefficiencies of the current communications used for emergency response include lack of technology inter-operability between different jurisdictions, and high vulnerability due to their centralized infrastructure. In this article, we propose a flexible network architecture that provides a common networking platform for heterogeneous multi-operator networks, for interoperation in case of emergencies. A wireless mesh network is the main part of the proposed architecture and this provides a back-up network in case of emergencies. We first describe the shortcomings and limitations of the current technologies, and then we address issues related to the applications and functionalities a future emergency response network should support. Furthermore, we describe the necessary requirements for a flexible, secure, robust, and QoS-aware emergency response multi-operator architecture, and then we suggest several schemes that can be adopted by our proposed architecture to meet those requirements. In addition, we suggest several methods for the re-tasking of communication means owned by independent individuals to provide support during emergencies. In order to investigate the feasibility of multimedia transmission over a wireless mesh network, we measured the performance of a video streaming application in a real wireless metropolitan multi-radio mesh network, showing that the mesh network can meet the requirements for high quality video transmissions

    Achievable bandwidth estimation for stations in multi-rate IEEE 802.11 WLAN cells

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    This paper analyzes the effect of multi-rate transmissions in a CSMA wireless LAN environment. Observations in a real testbed showed that bandwidth resources (in Bytes/s) are shared fairly among all stations even though transmissions carried out at lower rates capture the medium for longer periods, which drastically reduces the overall throughput. The intrinsic concept of fairness in a CSMA scheme with multiple rates is quantified by means of a new formulation which is validated through simulations and practical measurements. The algorithm presented provides the maximum achievable bandwidth that can be offered to a given IEEE 802.11 station. Having this information has evident applications in realtime multimedia transmissions over WLANs. The algorithm was also run in commercial APs as a proof of concept, after analyzing its implementation issues

    Final report on the evaluation of RRM/CRRM algorithms

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    Deliverable public del projecte EVERESTThis deliverable provides a definition and a complete evaluation of the RRM/CRRM algorithms selected in D11 and D15, and evolved and refined on an iterative process. The evaluation will be carried out by means of simulations using the simulators provided at D07, and D14.Preprin

    Survey of Transportation of Adaptive Multimedia Streaming service in Internet

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    [DE] World Wide Web is the greatest boon towards the technological advancement of modern era. Using the benefits of Internet globally, anywhere and anytime, users can avail the benefits of accessing live and on demand video services. The streaming media systems such as YouTube, Netflix, and Apple Music are reining the multimedia world with frequent popularity among users. A key concern of quality perceived for video streaming applications over Internet is the Quality of Experience (QoE) that users go through. Due to changing network conditions, bit rate and initial delay and the multimedia file freezes or provide poor video quality to the end users, researchers across industry and academia are explored HTTP Adaptive Streaming (HAS), which split the video content into multiple segments and offer the clients at varying qualities. The video player at the client side plays a vital role in buffer management and choosing the appropriate bit rate for each such segment of video to be transmitted. A higher bit rate transmitted video pauses in between whereas, a lower bit rate video lacks in quality, requiring a tradeoff between them. The need of the hour was to adaptively varying the bit rate and video quality to match the transmission media conditions. Further, The main aim of this paper is to give an overview on the state of the art HAS techniques across multimedia and networking domains. A detailed survey was conducted to analyze challenges and solutions in adaptive streaming algorithms, QoE, network protocols, buffering and etc. It also focuses on various challenges on QoE influence factors in a fluctuating network condition, which are often ignored in present HAS methodologies. Furthermore, this survey will enable network and multimedia researchers a fair amount of understanding about the latest happenings of adaptive streaming and the necessary improvements that can be incorporated in future developments.Abdullah, MTA.; Lloret, J.; Canovas Solbes, A.; GarcĂ­a-GarcĂ­a, L. (2017). Survey of Transportation of Adaptive Multimedia Streaming service in Internet. Network Protocols and Algorithms. 9(1-2):85-125. doi:10.5296/npa.v9i1-2.12412S8512591-

    Quality of service based distributed control of wireless networks

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    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
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