54 research outputs found

    A Seamless Vertical Handoff Protocol for Enhancing the Performance of Data Services in Integrated UMTS/WLAN Network

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    The Next Generation Wireless Network (NGWN) is speculated to be a unified network composed of several existing wireless access networks such as Wireless Local Area Network (WLAN), Global System for Mobile (GSM), Universal Mobile Telecommunications System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX), and satellite network etc

    Integrated Support for Handoff Management and Context-Awareness in Heterogeneous Wireless Networks

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    The overwhelming success of mobile devices and wireless communications is stressing the need for the development of mobility-aware services. Device mobility requires services adapting their behavior to sudden context changes and being aware of handoffs, which introduce unpredictable delays and intermittent discontinuities. Heterogeneity of wireless technologies (Wi-Fi, Bluetooth, 3G) complicates the situation, since a different treatment of context-awareness and handoffs is required for each solution. This paper presents a middleware architecture designed to ease mobility-aware service development. The architecture hides technology-specific mechanisms and offers a set of facilities for context awareness and handoff management. The architecture prototype works with Bluetooth and Wi-Fi, which today represent two of the most widespread wireless technologies. In addition, the paper discusses motivations and design details in the challenging context of mobile multimedia streaming applications

    A Seamless Vertical Handoff Protocol for Enhancing the Performance of Data Services in Integrated UMTS/WLAN Network

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    The Next Generation Wireless Network (NGWN) is speculated to be a unified network composed of several existing wireless access networks such as Wireless Local Area Network (WLAN), Global System for Mobile (GSM), Universal Mobile Telecommunications System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX), and satellite network etc

    Implementation of Vertical Handoff Algorithm between IEEE802.11 WLAN and CDMA Cellular Network

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    Today’s wireless users expect great things from tomorrow’s wireless networks. These expectations have been fueled by hype about what the next generations of wireless networks will offer. The rapid increase of wireless subscribers increases the quality of services anytime, anywhere, and by any-media becoming indispensable. Integration of various networks such as CDMA2000 and wireless LAN into IP-based networks is required in these kinds of services, which further requires a seamless vertical handoff to 4th generation wireless networks. The proposed handoff algorithm between WLAN and CDMA2000 cellular network is implemented. The results of the simulation shows the behavior of the handoff and the time spent in WLAN or CDMA. The number of weak signal beacons determines whether a handoff is required or not. In this algorithm, traffic is classified into real-time and non real-time services

    HAND-OFF VERTICAL Y LOS PROTOCOLOS IP COMO FACTORES CLAVE DEL DESARROLLO DE LAS REDES 4G

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    Este artĂ­culo describe lo que son en esencia las redes 4G y muestra un mapa general de su desarrollo tecnolĂłgico y se centra principalmente en dos temas principales: el Hand-off Vertical y el uso de IP, porque, como se explica en el artĂ­culo, estos dos factores son claves para el desarrollo de este nuevo tipo de redes por lo que sirve como una referencia que expande la visiĂłn sobre las redes 4G y muestra el papel del hand-off en su desarrollo para cualquier persona que le interese este tema. Esto es importante, dada la variedad de tecnologĂ­as que convergen en el esquema 4G

    Adaptive Vertical Handoff for Integrated UMTS and WLAN Networks

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    Next-generation wireless networks have been envisioned to be an integration of heterogeneous wireless access networks such as UMTS (Universal Mobile Telecommunication Networks) and the IEEE 802.11 based WLAN (Wireless Local Area Networks). It is an important and challenging issue to support seamless vertical handoff management in such an integrated architecture that provides the mobile users uninterrupted service continuity anywhere, any time. In such a networking environment, the signaling delay of the vertical handoff is not fixed due to the traffic load in the backbone Internet, wireless channel quality and the distance between a mobile node and its home network. However, the currently handoff solutions implicitly considers the signaling delay as a constant value. In this thesis, we study a typical link layer assisted handoff, identifying its deficiency due to the considerably large handoff delay. We propose an adaptive vertical handoff management scheme for integrated UMTS and WLAN networks. The proposed scheme incorporates the idea of pre-handoff with adaptive handoff threshold. We estimate the handoff signaling delay in advance, therefore, providing the delay information required for making an adaptive handoff decision. Instead of setting a fixed threshold, an adaptive handoff threshold value is determined for every single MN based on the estimated handoff signaling delay. The RSS and the RSS's rate of change are used to determine the estimated handoff time instant. Extensive simulation has been conducted to verify the performance of the proposed handoff scheme

    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

    An architectural framework for heterogeneous networking.

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    The growth over the last decade in the use of wireless networking devices has been explosive. Soon many devices will have multiple network interfaces, each with very different characteristics. We believe that a framework that encapsulates the key challenges of heterogeneous networking is required. Like a map clearly helps one to plan a journey, a framework is needed to help us move forward in this unexplored area. The approach taken here is similar to the OSImodel in which tightly defined layers are used to specify functionality, allowing a modular approach to the extension of systems and the interchange of their components, whilst providing a model that is more oriented to heterogeneity and mobility

    Mobility management in 5G heterogeneous networks

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    In recent years, mobile data traffic has increased exponentially as a result of widespread popularity and uptake of portable devices, such as smartphones, tablets and laptops. This growth has placed enormous stress on network service providers who are committed to offering the best quality of service to consumer groups. Consequently, telecommunication engineers are investigating innovative solutions to accommodate the additional load offered by growing numbers of mobile users. The fifth generation (5G) of wireless communication standard is expected to provide numerous innovative solutions to meet the growing demand of consumer groups. Accordingly the ultimate goal is to achieve several key technological milestones including up to 1000 times higher wireless area capacity and a significant cut in power consumption. Massive deployment of small cells is likely to be a key innovation in 5G, which enables frequent frequency reuse and higher data rates. Small cells, however, present a major challenge for nodes moving at vehicular speeds. This is because the smaller coverage areas of small cells result in frequent handover, which leads to lower throughput and longer delay. In this thesis, a new mobility management technique is introduced that reduces the number of handovers in a 5G heterogeneous network. This research also investigates techniques to accommodate low latency applications in nodes moving at vehicular speeds
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