68 research outputs found

    An investigation into the viability of UWB as lower-layer for Bluetooth

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    This report presents an investigation into some merging options between an upper-layer Bluetooth (BT) protocol stack with a lower-layer ECMA-368/9 Ultra Wideband (UWB) radio connection. A Bluetooth over Ultra Wideband (BToUWB) system is implemented by channelling an existing compliant Bluetooth connection’s data over an Ultra Wideband Medium Access Control (MAC) and Physical (PHY) layer radio channel. The aim of this project is to provide a description of the methodology used to create a BToUWB link and evaluate some advantages pertaining to the merger between the two Wireless Personal Area Network (WPAN) technologies. Prior to channelling data over a UWB connection, a compliant Bluetooth and UWB connection were configured between two Linux enabled computers by use of Bluetooth and UWB enabled Universal Serial Bus (USB) dongles. BlueZ, the official Bluetooth stack for Linux, were used to implement a modified Bluetooth stack. By modifying the open source BlueZ files, the Host Controller Interface (HCI) commands sent to the HCI sublayer by upper layer Logical Link Control and Adaptation Protocol (L2CAP) and Synchronous Connection-Oriented (SCO) implementations were hijacked and routed to a UWB “router and convergence” implementation for transmission over the UWB subsytem. Similarly lower level HCI events were spoofed to the L2CAP and SCO layers by the UWB convergence implementation upon receiving packets from the UWB subsystem. The commercial availability of UWB hardware through Wireless USB dongles enabled the realization of a compliant UWB link between the systems, requiring special driver modifications and Intel provided firmware to establish a WiMedia Logical Link Control Protocol (WLP) network. A specially developed test program generates L2CAP, Radio Frequency Communication (RFCOMM) and SCO Bluetooth data for testing the BToUWB link. The various Bluetooth data packets are routed from the Bluetooth stack to a developed kernel space routing module, which encapsulated the packets and route them via the WLP interface over the wireless high-speed UWB network to the remote system. On the remote side, the packets propagate its way back up through the UWB hardware and software module, and to the router module via call-back functions in the WLP interface. The router module strips the headers and injects the packets back into the Bluetooth L2CAP, RFCOMM or SCO layer for further Bluetooth processing. A test program running on the remote system, receives the test data and loops it back for asynchronous analyses, or stores it for later comparison in synchronous analyses. The results obtained from the system analyses shows how a Bluetooth system can benefit from implementing UWB as lower layer wireless interface over a short range by either improved asynchronous bandwidth, or synchronous reliability. The results also show some limitations of the pilot UWB hardware and firmware available over longer distances. In general, the successful transmission of Bluetooth data over the BToUWB implemented system proves the HCI layer to be a viable mergence point between the two protocols.Dissertation (MEng)--University of Pretoria, 2009.Electrical, Electronic and Computer Engineeringunrestricte

    A Review of UWB MAC Protocols

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    In this paper, we review several ultra-wideband (UWB) medium access control (MAC) protocols that have been proposed to date. This review then considers the possibility of developing an optimal MAC layer for high data rate UWB transmission systems that transmit very little power especially in application to mobile devices. MAC in UWB wireless networks is necessary to coordinate channel access among competing devices. Unique UWB characteristics offer great challenges and opportunities in effective UWB MAC design. We first present the background of UWB and the concept of MAC protocols for UWB. Secondly, we summarize four UWB MAC protocols that have been proposed by other researchers and finally, a conclusion with a view to the planned future work. The main contribution of this paper is that it presents a summarised version of several MAC protocols applicable to UWB systems. This will hopefully initiate further research and developments in UWB MAC protocol design

    Proposal of C4MS and inherent technical challenges – D3.1

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    Deliverable D3.1 del projecte Europeu OneFIT (ICT-2009-257385)The scope of OneFIT is on Opportunistic etworks and Cognitive Management Systems for Efficient Application Provision in the uture Internet. This document contains a proposal of Control Channels for Coordination of Cognitive Management Systems (C4MS) which enables delivery of guidance/assistance information from infrastructure towards the Opportunistic Networks and provides means for the management of Opportunistic Networks. This document defines first messages and elementary procedures for the C4MS as well as it identifies a preliminary set of information which is to be conveyed over C4MS. The document introduces also the inherent technical challenges related to the C4MS proposal.Postprint (published version

    Wireless Network Communications Overview for Space Mission Operations

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    The mission of the On-Board Wireless Working Group (WWG) is to serve as a general CCSDS focus group for intra-vehicle wireless technologies. The WWG investigates and makes recommendations pursuant to standardization of applicable wireless network protocols, ensuring the interoperability of independently developed wireless communication assets. This document presents technical background information concerning uses and applicability of wireless networking technologies for space missions. Agency-relevant driving scenarios, for which wireless network communications will provide a significant return-on-investment benefiting the participating international agencies, are used to focus the scope of the enclosed technical information

    Quality-Oriented Mobility Management for Multimedia Content Delivery to Mobile Users

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    The heterogeneous wireless networking environment determined by the latest developments in wireless access technologies promises a high level of communication resources for mobile computational devices. Although the communication resources provided, especially referring to bandwidth, enable multimedia streaming to mobile users, maintaining a high user perceived quality is still a challenging task. The main factors which affect quality in multimedia streaming over wireless networks are mainly the error-prone nature of the wireless channels and the user mobility. These factors determine a high level of dynamics of wireless communication resources, namely variations in throughput and packet loss as well as network availability and delays in delivering the data packets. Under these conditions maintaining a high level of quality, as perceived by the user, requires a quality oriented mobility management scheme. Consequently we propose the Smooth Adaptive Soft-Handover Algorithm, a novel quality oriented handover management scheme which unlike other similar solutions, smoothly transfer the data traffic from one network to another using multiple simultaneous connections. To estimate the capacity of each connection the novel Quality of Multimedia Streaming (QMS) metric is proposed. The QMS metric aims at offering maximum flexibility and efficiency allowing the applications to fine tune the behavior of the handover algorithm. The current simulation-based performance evaluation clearly shows the better performance of the proposed Smooth Adaptive Soft-Handover Algorithm as compared with other handover solutions. The evaluation was performed in various scenarios including multiple mobile hosts performing handover simultaneously, wireless networks with variable overlapping areas, and various network congestion levels

    Ubiquitous Computing

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    The aim of this book is to give a treatment of the actively developed domain of Ubiquitous computing. Originally proposed by Mark D. Weiser, the concept of Ubiquitous computing enables a real-time global sensing, context-aware informational retrieval, multi-modal interaction with the user and enhanced visualization capabilities. In effect, Ubiquitous computing environments give extremely new and futuristic abilities to look at and interact with our habitat at any time and from anywhere. In that domain, researchers are confronted with many foundational, technological and engineering issues which were not known before. Detailed cross-disciplinary coverage of these issues is really needed today for further progress and widening of application range. This book collects twelve original works of researchers from eleven countries, which are clustered into four sections: Foundations, Security and Privacy, Integration and Middleware, Practical Applications

    Space station data system analysis/architecture study. Task 2: Options development, DR-5. Volume 2: Design options

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    The primary objective of Task 2 is the development of an information base that will support the conduct of trade studies and provide sufficient data to make key design/programmatic decisions. This includes: (1) the establishment of option categories that are most likely to influence Space Station Data System (SSDS) definition; (2) the identification of preferred options in each category; and (3) the characterization of these options with respect to performance attributes, constraints, cost and risk. This volume contains the options development for the design category. This category comprises alternative structures, configurations and techniques that can be used to develop designs that are responsive to the SSDS requirements. The specific areas discussed are software, including data base management and distributed operating systems; system architecture, including fault tolerance and system growth/automation/autonomy and system interfaces; time management; and system security/privacy. Also discussed are space communications and local area networking
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