61 research outputs found

    Fourth Generation Wireless Systems: Requirements and Challenges for the Next Frontier

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    Fourth generation wireless systems (4G) are likely to reach the consumer market in another 4-5 years. 4G comes with the promise of increased bandwidth, higher speeds, greater interoperability across communication protocols, and user friendly, innovative, and secure applications. In this article, I list the requirements of the 4G systems by considering the needs of the users in the future. These requirements can be met if technical and business challenges can be overcome. Technical challenges include mobility management, quality of service, interoperability, high data rate, security, survivability, spectrum, intelligent mobile devices, middleware, and network access. I discuss the most plausible solutions to these technical challenges in this paper. Business-related challenges include billing, payment methods, pricing, size of investments, content provision and mediation, and the trade-off between richness and reach. If these technical and business challenges can be met, then 4G will become the next frontier in data and voice communication infrastructure

    Recent Advances in Wireless Communications and Networks

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    This book focuses on the current hottest issues from the lowest layers to the upper layers of wireless communication networks and provides "real-time" research progress on these issues. The authors have made every effort to systematically organize the information on these topics to make it easily accessible to readers of any level. This book also maintains the balance between current research results and their theoretical support. In this book, a variety of novel techniques in wireless communications and networks are investigated. The authors attempt to present these topics in detail. Insightful and reader-friendly descriptions are presented to nourish readers of any level, from practicing and knowledgeable communication engineers to beginning or professional researchers. All interested readers can easily find noteworthy materials in much greater detail than in previous publications and in the references cited in these chapters

    A Review of Service Quality in Integrated Networking System at the Hospital Scenarios

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    Hospital networking system is progressing into a more unified method by connecting technology that utilizes wireless networking technologies into backbone networks. Even though multiple joined circumstances have been acknowledged in the published articles, a common medical facility has not been thoroughly studied and continued to be a difficult subject that is pending. The main challenge faced by networking consultants is the smooth unification of all the components in an all-in-one of healthcare delivery system.  A perfect understanding of the functions of the unified networking is essential for effective designing and utilization of such knowledge in the medical backgrounds. This paper denotes the design and review of unified networking system circumstances in a hospital background. The effect of the types of traffic for example the audio and visual, system loads, size and strength of the network line is studied by a test run. Three pilot test studies have been conducted in radiology A&E and ICU conditions. Each condition shows the requirements for a particular type of traffic which then becomes the definite system behaviour. In the case of a radiology requirement, email and FTP traffic are noted to function effectively within the regular-to-big networking systems. In an A&E situation, VoIP circulations create very little jitters and missing data; it is linked with the prerequisites of QoS. In ICU situations, the video conferencing function downgrades the size of the network. Therefore, a QoS enabled gadget is suggested to minimise the packet delay and data losses. This study gives an overall explanation of wireless telemedicine technology and QoS. The findings of this study are summarised and arranged. Besides, the quality of service which has to be studied through the wireless telemedicine technology has been indicated. The findings of this study will provide a useful perspective in the investigation of QoS in wireless telemedicine technology and serve as a foundation for any individuals who are intrigued in the research of “wireless telemedicine technology for e-healthcare service

    Acesso banda larga sem fios em ambientes heterogéneos de próxima geração

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    Doutoramento em Engenharia InformĂĄticaO acesso ubĂ­quo Ă  Internet Ă© um dos principais desafios para os operadores de telecomunicaçÔes na prĂłxima dĂ©cada. O nĂșmero de utilizadores da Internet estĂĄ a crescer exponencialmente e o paradigma de acesso "always connected, anytime, anywhere" Ă© um requisito fundamental para as redes mĂłveis de prĂłxima geração. A tecnologia WiMAX, juntamente com o LTE, foi recentemente reconhecida pelo ITU como uma das tecnologias de acesso compatĂ­veis com os requisitos do 4G. Ainda assim, esta tecnologia de acesso nĂŁo estĂĄ completamente preparada para ambientes de prĂłxima geração, principalmente devido Ă  falta de mecanismos de cross-layer para integração de QoS e mobilidade. Adicionalmente, para alĂ©m das tecnologias WiMAX e LTE, as tecnologias de acesso rĂĄdio UMTS/HSPA e Wi-Fi continuarĂŁo a ter um impacto significativo nas comunicaçÔes mĂłveis durante os prĂłximos anos. Deste modo, Ă© fundamental garantir a coexistĂȘncia das vĂĄrias tecnologias de acesso rĂĄdio em termos de QoS e mobilidade, permitindo assim a entrega de serviços multimĂ©dia de tempo real em redes mĂłveis. Para garantir a entrega de serviços multimĂ©dia a utilizadores WiMAX, esta Tese propĂ”e um gestor cross-layer WiMAX integrado com uma arquitectura de QoS fim-a-fim. A arquitectura apresentada permite o controlo de QoS e a comunicação bidireccional entre o sistema WiMAX e as entidades das camadas superiores. Para alĂ©m disso, o gestor de cross-layer proposto Ă© estendido com eventos e comandos genĂ©ricos e independentes da tecnologia para optimizar os procedimentos de mobilidade em ambientes WiMAX. Foram realizados testes para avaliar o desempenho dos procedimentos de QoS e mobilidade da arquitectura WiMAX definida, demonstrando que esta Ă© perfeitamente capaz de entregar serviços de tempo real sem introduzir custos excessivos na rede. No seguimento das extensĂ”es de QoS e mobilidade apresentadas para a tecnologia WiMAX, o Ăąmbito desta Tese foi alargado para ambientes de acesso sem-fios heterogĂ©neos. Neste sentido, Ă© proposta uma arquitectura de mobilidade transparente com suporte de QoS para redes de acesso multitecnologia. A arquitectura apresentada integra uma versĂŁo estendida do IEEE 802.21 com suporte de QoS, bem como um gestor de mobilidade avançado integrado com os protocolos de gestĂŁo de mobilidade do nĂ­vel IP. Finalmente, para completar o trabalho desenvolvido no Ăąmbito desta Tese, Ă© proposta uma extensĂŁo aos procedimentos de decisĂŁo de mobilidade em ambientes heterogĂ©neos para incorporar a informação de contexto da rede e do terminal. Para validar e avaliar as optimizaçÔes propostas, foram desenvolvidos testes de desempenho num demonstrador inter-tecnologia, composta pelas redes de acesso WiMAX, Wi-Fi e UMTS/HSPA.Ubiquitous Internet access is one of the main challenges for the telecommunications industry in the next decade. The number of users accessing the Internet is growing exponentially and the network access paradigm of “always connected, anytime, anywhere” is a central requirement for the so-called Next Generation Mobile Networks (NGMN). WiMAX, together with LTE, was recently recognized by ITU as one of the compliant access technologies for 4G. Nevertheless, WiMAX is not yet fully prepared for next generation environments, mainly due to the lack of QoS and mobility crosslayer procedures to support real-time multimedia services delivery. Furthermore, besides the 4G compliant WiMAX and LTE radio access technologies, UMTS/HSPA and Wi-Fi will also have a significant impact in the mobile communications during the next years. Therefore, it is fundamental to ensure the coexistence of multiple radio access technologies in what QoS and mobility procedures are concerned, thereby allowing the delivery of real-time services in mobile networks. In order to provide the WiMAX mobile users with the demanded multimedia services, it is proposed in this Thesis a WiMAX cross-layer manager integrated in an end-to-end all-IP QoS enabled architecture. The presented framework enables the QoS control and bidirectional communication between WiMAX and the upper layer network entities. Furthermore, the proposed cross-layer framework is extended with media independent events and commands to optimize the mobility procedures in WiMAX environments. Tests were made to evaluate the QoS and mobility performance of the defined architecture, demonstrating that it is perfectly capable of handling and supporting real time services without introducing an excessive cost in the network. Following the QoS and mobility extensions provided for WiMAX, the scope of this Thesis is broaden and a seamless mobility architecture with QoS support in heterogeneous wireless access environments is proposed. The presented architecture integrates an extended version of the IEEE 802.21 framework with QoS support, as well as an advanced mobility manager integrated with the IP level mobility management protocols. Finally, to complete the work within the framework of this Thesis, it is proposed an extension to the handover decisionmaking processes in heterogeneous access environments through the integration of context information from both the network entities and the enduser. Performance tests were developed in a real testbed to validate the proposed optimizations in an inter-technology handover scenario involving WiMAX, Wi-Fi and UMTS/HSPA

    Integrating Context-Awareness in the IP Multimedia Subsystem for Enhanced Session Control and Service Provisioning Capabilities

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    The 3GPP-defined IP Multimedia Subsystem (IMS) is becoming the de-facto standard for IP-based multimedia communication services. It consists of an overlay control and service layer that is deployed on top of IP-based mobile and fixed networks. This layer encompasses a set of common functions (e.g. session control functions allowing the initiation/modification/termination of sessions) and service logics that are needed for the seamless provisioning of IP multimedia services to users, via different access technologies. As it continues to evolve, the IMS still faces several challenges including: the enabling of innovative and personalized services that would appeal to users and increase network operators' revenues; its interaction with other types of networks (e.g. wireless sensor networks) as means to enhance its capabilities; and the support of advanced QoS schemes that would manage the network resources in an efficient and adaptive manner. The context-awareness concept, which comes from the pervasive computing field, signifies the ability to use situational information (or context) in support to operations and decision making and for the provision of relevant services to the user. Context-awareness is considered to enhance users' experience and is seen as an enabler to adaptability and service personalization - two capabilities that could play important roles in telecommunication environments. This thesis focuses on the introduction of the context-awareness technology in the IMS, as means to enhance its session control and service provisioning capabilities. It starts by presenting the necessary background information, followed by a derivation of requirements and a review of the related work. To ensure the availability of contextual information within the network, we then propose an architecture for context information acquisition and management in the IMS. This architecture leverages and extends the 3GPP presence framework. Building on the capabilities of this architecture, we demonstrate how the managed information could be integrated in IMS operations, at the control and service levels. Showcasing control level integration, we propose a novel context-aware call differentiation framework as means to offer enhanced QoS support (for sessions/calls) in IMS-based networks. This framework enables the differentiation between different categories of calls at the IMS session control level, via dynamic and adaptive resource allocation, in addition to supporting a specialized charging model. Furthermore, we also propose a framework for enhanced IMS emergency communication services. This framework addresses the limitations of existing IP-based emergency solutions, by offering three main improvements: a QoS-enhanced emergency service; a context-aware personalized emergency service; and a conferencing-enhanced emergency service. We demonstrate the use of context awareness at the IMS service level using two new context-aware IMS applications. Finally, to validate our solutions and evaluate their performance, we build various proof-of-concept prototypes and OPNET simulation model

    Radio Communications

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    In the last decades the restless evolution of information and communication technologies (ICT) brought to a deep transformation of our habits. The growth of the Internet and the advances in hardware and software implementations modiïŹed our way to communicate and to share information. In this book, an overview of the major issues faced today by researchers in the ïŹeld of radio communications is given through 35 high quality chapters written by specialists working in universities and research centers all over the world. Various aspects will be deeply discussed: channel modeling, beamforming, multiple antennas, cooperative networks, opportunistic scheduling, advanced admission control, handover management, systems performance assessment, routing issues in mobility conditions, localization, web security. Advanced techniques for the radio resource management will be discussed both in single and multiple radio technologies; either in infrastructure, mesh or ad hoc networks

    Telecommunications Networks

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    This book guides readers through the basics of rapidly emerging networks to more advanced concepts and future expectations of Telecommunications Networks. It identifies and examines the most pressing research issues in Telecommunications and it contains chapters written by leading researchers, academics and industry professionals. Telecommunications Networks - Current Status and Future Trends covers surveys of recent publications that investigate key areas of interest such as: IMS, eTOM, 3G/4G, optimization problems, modeling, simulation, quality of service, etc. This book, that is suitable for both PhD and master students, is organized into six sections: New Generation Networks, Quality of Services, Sensor Networks, Telecommunications, Traffic Engineering and Routing
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