31,428 research outputs found

    HIP-based Handover Mechanism under MIH Architecture in Heterogeneous Wireless Networks

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    [[abstract]]In this paper, we offers a HIP-based vertical handover scheme under MIH architecture in heterogeneous wireless network. Many diversity wireless access technologies are offering in Next Generation Wireless Networks (NGWN). In NGWN, the integration of wireless access network will be accomplished by seamless handover which contains many challenges i.e. service mobility, vertical handover, common authentication, unified accounting/billing, security mechanisms, QoS and service provisioning, etc. Toward this direction, our research aims to provide a complete integration of heterogeneous network architecture and support a fit mobility management for network to seamless handover. We focus on simulation about vertical handover execution for WiMAX to WiFi scenario. Our idea can modify defects of Mobile IP and SIP. And it provides internet users always best connection. Moreover, we hope to contribute our research to beyond 4G wireless networks.[[notice]]補正完畢[[conferencetype]]國際[[conferencedate]]20110621~20110623[[booktype]]紙本[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]Gyeongju, Korea[[countrycodes]]KO

    Flat Cellular (UMTS) Networks

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    Traditionally, cellular systems have been built in a hierarchical manner: many specialized cellular access network elements that collectively form a hierarchical cellular system. When 2G and later 3G systems were designed there was a good reason to make system hierarchical: from a cost-perspective it was better to concentrate traffic and to share the cost of processing equipment over a large set of users while keeping the base stations relatively cheap. However, we believe the economic reasons for designing cellular systems in a hierarchical manner have disappeared: in fact, hierarchical architectures hinder future efficient deployments. In this paper, we argue for completely flat cellular wireless systems, which need just one type of specialized network element to provide radio access network (RAN) functionality, supplemented by standard IP-based network elements to form a cellular network. While the reason for building a cellular system in a hierarchical fashion has disappeared, there are other good reasons to make the system architecture flat: (1) as wireless transmission techniques evolve into hybrid ARQ systems, there is less need for a hierarchical cellular system to support spatial diversity; (2) we foresee that future cellular networks are part of the Internet, while hierarchical systems typically use interfaces between network elements that are specific to cellular standards or proprietary. At best such systems use IP as a transport medium, not as a core component; (3) a flat cellular system can be self scaling while a hierarchical system has inherent scaling issues; (4) moving all access technologies to the edge of the network enables ease of converging access technologies into a common packet core; and (5) using an IP common core makes the cellular network part of the Internet

    Proactive Highly Ambulatory Sensor Routing (PHASeR) protocol for mobile wireless sensor networks

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    This paper presents a novel multihop routing protocol for mobile wireless sensor networks called PHASeR (Proactive Highly Ambulatory Sensor Routing). The proposed protocol uses a simple hop-count metric to enable the dynamic and robust routing of data towards the sink in mobile environments. It is motivated by the application of radiation mapping by unmanned vehicles, which requires the reliable and timely delivery of regular measurements to the sink. PHASeR maintains a gradient metric in mobile environments by using a global TDMA MAC layer. It also uses the technique of blind forwarding to pass messages through the network in a multipath manner. PHASeR is analysed mathematically based on packet delivery ratio, average packet delay, throughput and overhead. It is then simulated with varying mobility, scalability and traffic loads. The protocol gives good results over all measures, which suggests that it may also be suitable for a wider array of emerging applications
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