1,774 research outputs found

    MIRAI Architecture for Heterogeneous Network

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    One of the keywords that describe next-generation wireless communications is "seamless." As part of the e-Japan Plan promoted by the Japanese Government, the Multimedia Integrated Network by Radio Access Innovation project has as its goal the development of new technologies to enable seamless integration of various wireless access systems for practical use by 2005. This article describes a heterogeneous network architecture including a common tool, a common platform, and a common access. In particular, software-defined radio technologies are used to develop a multiservice user terminal to access different wireless networks. The common platform for various wireless networks is based on a wireless-supporting IPv6 network. A basic access network, separated from other wireless access networks, is used as a means for wireless system discovery, signaling, and paging. A proof-of-concept experimental demonstration system is available

    Quality of Service over Specific Link Layers: state of the art report

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    The Integrated Services concept is proposed as an enhancement to the current Internet architecture, to provide a better Quality of Service (QoS) than that provided by the traditional Best-Effort service. The features of the Integrated Services are explained in this report. To support Integrated Services, certain requirements are posed on the underlying link layer. These requirements are studied by the Integrated Services over Specific Link Layers (ISSLL) IETF working group. The status of this ongoing research is reported in this document. To be more specific, the solutions to provide Integrated Services over ATM, IEEE 802 LAN technologies and low-bitrate links are evaluated in detail. The ISSLL working group has not yet studied the requirements, that are posed on the underlying link layer, when this link layer is wireless. Therefore, this state of the art report is extended with an identification of the requirements that are posed on the underlying wireless link, to provide differentiated Quality of Service

    Satellite ATM network architectures: An overview

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    A satellite ATM network has been envisioned as the next information super-skyway. There has been a migration from traditional bent pipe satellites to onboard processing) ATM satellites. The current congestion in the Internet has motivated the use of alternate paths - using satellites to support global Internet transport and access. This article presents the various system and protocol layer architectures of SATM networks.published_or_final_versio

    A framework for fast handoff schemes in wireless ATM networks

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    Includes bibliographical references.In this research, we focus on providing a framework that extends the fixed ATM standard to support user mobility in future WATM networks. The WATM architecture allows for the migration of fixed ATM networks without major modifications. Thus most of the mobility functions are implemented on the wireless access network. The most important component supporting mobility in a cluster is the Mobility Enhanced Switch (MES). We propose using direct links between adjacent MESs to support Permanent Virtual Channels (PVCs) in order to facilitate fast inter-cluster handoffwith minimum handofflatency. This research addresses a framework on handoff mobility by proposing three fast handoff re-routing schemes based on the support of PVCs

    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

    An investigation into advance time division multiple access based personal communication networks : this thesis is presented in partial fulfilment of the requirements for the degree of Master of Technology in Production Technology at Massey University

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    This thesis examines and simulates a statistically multiplexed multiple access technique known as Advanced Time Division Multiple Access (ATDMA). The simulations were carried out in a multimedia traffic environment. Parameters that could optimise the network performance in terms of quality, reliability and capacity have been examined using a simulation model. This thesis also examines network architecture and signalling related issues. The simulation results were analysed to propose a suitable ATDMA frame structure in terms of the frame length and the organisation of traffic and reservation slots. The simulation results indicated that the performance of the ATDMA based system can be enhanced when delay insensitive data is transmitted as blocks of packets of a specific size. The simulation results also indicated that the performance of the ATDMA based system can be further enhanced when a video terminal is allocated a single traffic slot as opposed to multiple traffic slots. Further simulations have been carried out to determine the up-link traffic channel capacities and control channel capacities. This thesis also examined aspects that could further enhance the performance of an ATDMA based system

    Wireless Internet on Heterogeneous Networks

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