82,284 research outputs found

    Sensornet checkpointing: enabling repeatability in testbeds and realism in simulations

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    When developing sensor network applications, the shift from simulation to testbed causes application failures, resulting in additional time-consuming iterations between simulation and testbed. We propose transferring sensor network checkpoints between simulation and testbed to reduce the gap between simulation and testbed. Sensornet checkpointing combines the best of both simulation and testbeds: the nonintrusiveness and repeatability of simulation, and the realism of testbeds

    Algorithms and software for solving finite element equations on serial and parallel architectures

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    The primary objective was to compare the performance of state-of-the-art techniques for solving sparse systems with those that are currently available in the Computational Structural Mechanics (MSC) testbed. One of the first tasks was to become familiar with the structure of the testbed, and to install some or all of the SPARSPAK package in the testbed. A brief overview of the CSM Testbed software and its usage is presented. An overview of the sparse matrix research for the Testbed currently employed in the CSM Testbed is given. An interface which was designed and implemented as a research tool for installing and appraising new matrix processors in the CSM Testbed is described. The results of numerical experiments performed in solving a set of testbed demonstration problems using the processor SPK and other experimental processors are contained

    A Real-Time GPP Software-Defined Radio Testbed for the Physical Layer of Wireless Standards

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    We present our contribution to the general-purpose-processor-(GPP)-based radio. We describe a baseband software-defined radio testbed for the physical layer of wireless LAN standards. All physical layer functions have been successfully mapped on a Pentium 4 processor that performs these functions in real time. The testbed consists of a transmitter PC with a DAC board and a receiver PC with an ADC board. In our project, we have implemented two different types of standards on this testbed, a continuous-phase-modulation-based standard, Bluetooth, and an OFDM-based standard, HiperLAN/2. However, our testbed can easily be extended to other standards, because the only limitation in our testbed is the maximal channel bandwidth of 20 MHz and of course the processing capabilities of the used PC. The transmitter functions require at most 714 M cycles per second and the receiver functions need 1225 M cycles per second on a Pentium 4 processor. In addition, baseband experiments have been carried out successfully

    Sparse matrix methods research using the CSM testbed software system

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    Research is described on sparse matrix techniques for the Computational Structural Mechanics (CSM) Testbed. The primary objective was to compare the performance of state-of-the-art techniques for solving sparse systems with those that are currently available in the CSM Testbed. Thus, one of the first tasks was to become familiar with the structure of the testbed, and to install some or all of the SPARSPAK package in the testbed. A suite of subroutines to extract from the data base the relevant structural and numerical information about the matrix equations was written, and all the demonstration problems distributed with the testbed were successfully solved. These codes were documented, and performance studies comparing the SPARSPAK technology to the methods currently in the testbed were completed. In addition, some preliminary studies were done comparing some recently developed out-of-core techniques with the performance of the testbed processor INV

    Advanced turboprop testbed systems study. Volume 1: Testbed program objectives and priorities, drive system and aircraft design studies, evaluation and recommendations and wind tunnel test plans

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    The establishment of propfan technology readiness was determined and candidate drive systems for propfan application were identified. Candidate testbed aircraft were investigated for testbed aircraft suitability and four aircraft selected as possible propfan testbed vehicles. An evaluation of the four candidates was performed and the Boeing KC-135A and the Gulfstream American Gulfstream II recommended as the most suitable aircraft for test application. Conceptual designs of the two recommended aircraft were performed and cost and schedule data for the entire testbed program were generated. The program total cost was estimated and a wind tunnel program cost and schedule is generated in support of the testbed program

    A GPP-Based Software-Defined Radio Front-End for WLAN Standards

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    This paper presents a software-defined radio testbed for the physical layer of wireless LAN standards. All baseband physical layer functions have been successfully mapped on a Pentium 4 processor that performs these functions in real-time. This has been tested in combination with a CMOS integrated wideband analog front-end containing a low noise amplifier, downconversion mixers and filters. The testbed consists of both a transmitter and a receiver. The transmitter contains a transmitter PC with a DAC board, an Agilent E4438C generator for upconversion and an antenna. The receiver consists of an antenna, a wideband SDR analog frontend and a receiver PC with an ADC board. On this testbed we have implemented two different types of standards, a continuous-phase-modulation based standard, Bluetooth and an OFDM based standard, HiperLAN/2. However, our testbed can easily be extended to other standards, because the only limitations in our testbed are the maximal channel bandwidth of 20 MHz, the dynamic range of the wideband SDR analog front-end and of course the processing capabilities of the used PC

    A Millimeter Wave MIMO Testbed for 5G Communications

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    This paper presents a 2 x 2 millimeter wave (mm-wave) multiple-input-multiple-output (MIMO) testbed that operates at around 30 GHz. The link assessment of the system operating at 26.25 GHz was carried out on a test bench, with a short communication distance between the transmitting and receiving antennas. A user-programmable, reconfigurable and real-time signal processing field-programmable gate arrays (FPGAs)-based software defined radio (SDR) system was employed as part of the testbed to validate the system-level performance for a downlink time division long-term evolution (TD-LTE) duplex scheme. Constellation diagram for quadrature phase shift keying (QPSK) digital modulation were acquired while the testbed was operating at 30 GHz. The testbed could be employed for the development of signal test, communication algorithm and measurement metrology for 5G communications.Comment: 89th ARFTG Microwave Measurement Conference (ARFTG 2017

    Software-defined networking: guidelines for experimentation and validation in large-scale real world scenarios

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    Part 1: IIVC WorkshopInternational audienceThis article thoroughly details large-scale real world experiments using Software-Defined Networking in the testbed setup. More precisely, it provides a description of the foundation technology behind these experiments, which in turn is focused around OpenFlow and on the OFELIA testbed. In this testbed preliminary experiments were performed in order to tune up settings and procedures, analysing the encountered problems and their respective solutions. A methodology consisting of five large-scale experiments is proposed in order to properly validate and improve the evaluation techniques used in OpenFlow scenarios
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