152,781 research outputs found

    An Architectural Framework for Collaboration of Heterogeneous Communication Devices Using WAP and Mobile Device Augmented(MDA)Gateway Integration

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    Within the last couple of years, the challenge of displaying collaborative multimedia information has become very important with the large diversity of communication devices such as Personal Computers, laptops, notebooks and handheld devices. The shared data and information may be presented with different views depending on the communication device used by a particular collaborator. The use of various web tools (HTML, WML etc) offers some solutions to the problem but if the target application requires more complex features such as rich multimedia data than is manageable using HTML or WML format, something else need to be done. In this paper, we propose a framework that integrates WAP and MDA Gateway to support collaboration among virtual teams and nomadic workers using heterogeneous communication devices. We then discuss an approach for augmenting mobile device small screen capabilities with surrounding large screen display device

    QUALITY-DRIVEN CROSS LAYER DESIGN FOR MULTIMEDIA SECURITY OVER RESOURCE CONSTRAINED WIRELESS SENSOR NETWORKS

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    The strong need for security guarantee, e.g., integrity and authenticity, as well as privacy and confidentiality in wireless multimedia services has driven the development of an emerging research area in low cost Wireless Multimedia Sensor Networks (WMSNs). Unfortunately, those conventional encryption and authentication techniques cannot be applied directly to WMSNs due to inborn challenges such as extremely limited energy, computing and bandwidth resources. This dissertation provides a quality-driven security design and resource allocation framework for WMSNs. The contribution of this dissertation bridges the inter-disciplinary research gap between high layer multimedia signal processing and low layer computer networking. It formulates the generic problem of quality-driven multimedia resource allocation in WMSNs and proposes a cross layer solution. The fundamental methodologies of multimedia selective encryption and stream authentication, and their application to digital image or video compression standards are presented. New multimedia selective encryption and stream authentication schemes are proposed at application layer, which significantly reduces encryption/authentication complexity. In addition, network resource allocation methodologies at low layers are extensively studied. An unequal error protection-based network resource allocation scheme is proposed to achieve the best effort media quality with integrity and energy efficiency guarantee. Performance evaluation results show that this cross layer framework achieves considerable energy-quality-security gain by jointly designing multimedia selective encryption/multimedia stream authentication and communication resource allocation

    MusA: Using Indoor Positioning and Navigation to Enhance Cultural Experiences in a museum

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    In recent years there has been a growing interest into the use of multimedia mobile guides in museum environments. Mobile devices have the capabilities to detect the user context and to provide pieces of information suitable to help visitors discovering and following the logical and emotional connections that develop during the visit. In this scenario, location based services (LBS) currently represent an asset, and the choice of the technology to determine users' position, combined with the definition of methods that can effectively convey information, become key issues in the design process. In this work, we present MusA (Museum Assistant), a general framework for the development of multimedia interactive guides for mobile devices. Its main feature is a vision-based indoor positioning system that allows the provision of several LBS, from way-finding to the contextualized communication of cultural contents, aimed at providing a meaningful exploration of exhibits according to visitors' personal interest and curiosity. Starting from the thorough description of the system architecture, the article presents the implementation of two mobile guides, developed to respectively address adults and children, and discusses the evaluation of the user experience and the visitors' appreciation of these application

    A framework for the development of tolerant real time applications

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    This work presents a framework architecture for the development of distributed real-time applications to be integrated into WWW clients. It assumes a WWW environment over networks providing a best-effort delivery service like the internets based on the IP protocol. The framework is that of an application programming interface (API) providing the program developer with the services needed by tolerant realtime applications. Once developed, an application is bundled together with the API to form a WWW plug-in which can subsequently be called from a WWW client interface or browser. The application is then perceived as being integrated into the WWW environment. The design aims to provide real-time applications with a transport service layer assuring near end-to-end isochronism despite the weak guaranties of the underlying network service. The implementation of the mechanisms that allow multistream real-time communications to adapt to the operational conditions of these networks are discussed. In this work, the RTP and RTCP protocols were also implemented as part of the API. Experience with this framework reports the development of a prototype real-time application for multimedia group communication and the analysis of the behaviour of RTP sessions in a real operational situation. The analysis uses protocol state data logged during their operation

    Improving perceptual multimedia quality with an adaptable communication protocol

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    Copyrights @ 2005 University Computing Centre ZagrebInnovations and developments in networking technology have been driven by technical considerations with little analysis of the benefit to the user. In this paper we argue that network parameters that define the network Quality of Service (QoS) must be driven by user-centric parameters such as user expectations and requirements for multimedia transmitted over a network. To this end a mechanism for mapping user-oriented parameters to network QoS parameters is outlined. The paper surveys existing methods for mapping user requirements to the network. An adaptable communication system is implemented to validate the mapping. The architecture adapts to varying network conditions caused by congestion so as to maintain user expectations and requirements. The paper also surveys research in the area of adaptable communications architectures and protocols. Our results show that such a user-biased approach to networking does bring tangible benefits to the user

    Multimedia Teleservices Modelled with the OSI Application Layer Structure

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    This paper looks into the communications capabilities that are required by distributed multimedia applications to achieve relation preserving information exchange. These capabilities are derived by analyzing the notion of information exchange and are embodied in communications functionalities. To emphasize the importance of the users' view, a top-down approach is applied. The (revised) OSI Application Layer Structure (OSI-ALS) is used to model the communications functionalities and to develop an architecture for composition of multimedia services with these functionalities. This work may therefore be considered an exercise to evaluate the suitability of OSI-ALS for composition of multimedia teleservices

    Multicriteria decision making for enhanced perception-based multimedia communication

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    This paper proposes an approach that integrates technical concerns with user perceptual considerations for intelligent decision making in the construction of tailor-made multimedia communication protocols. Thus, the proposed approach, based on multicriteria decision making (MDM), incorporates not only classical networking considerations, but, indeed, user preferences as well. Furthermore, in keeping with the task-dependent nature consistently identified in multimedia scenarios, the suggested communication protocols also take into account the type of multimedia application that they are transporting. Lastly, this approach also opens the possibility for such protocols to dynamically adapt based on a changing operating environment and user's preferences

    An Open Framework for Integrating Widely Distributed Hypermedia Resources

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    The success of the WWW has served as an illustration of how hypermedia functionality can enhance access to large amounts of distributed information. However, the WWW and many other distributed hypermedia systems offer very simple forms of hypermedia functionality which are not easily applied to existing applications and data formats, and cannot easily incorporate alternative functions which would aid hypermedia navigation to and from existing documents that have not been developed with hypermedia access in mind. This paper describes the extension to a distributed environment of the open hypermedia functionality of the Microcosm system, which is designed to support the provision of hypermedia access to a wide range of source material and application, and to offer straightforward extension of the system to incorporate new forms of information access

    Multicriteria decision making for enhanced perception-based multimedia communication

    Get PDF
    This paper proposes an approach that integrates technical concerns with user perceptual considerations for intelligent decision making in the construction of tailor-made multimedia communication protocols. Thus, the proposed approach, based on multicriteria decision making (MDM), incorporates not only classical networking considerations, but, indeed, user preferences as well. Furthermore, in keeping with the task-dependent nature consistently identified in multimedia scenarios, the suggested communication protocols also take into account the type of multimedia application that they are transporting. Lastly, this approach also opens the possibility for such protocols to dynamically adapt based on a changing operating environment and user’s preferences
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