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In this paper we describe a systematic study on long-term evolution of residential broadband Internet traffic covering 5 calendar years from June 2007 to May 2011. The traffic evolution is characterized both in the term of the total traffic volume, as well as the traffic volumes and shares for different application categories (file sharing, video streaming etc.), with the focus on comparing the tr
The presented study deals with a specific rerouting strategy for protecting traffic flows in communication networks called Flow Adjustment Routing. The strategy is designed to handle partial link failures. We present two variants of the strategy and analyze their pros and cons. We show that the initial strategy is not directly implementable to cope with severe link failures such as total link fail
In software product line engineering, testing for regression concerns not only versions, as in one-off product development, but also regression across variants. We propose a 3D process model, with the dimensions of level, version and variant, to help analyze, plan and manage software product line testing. We derive the model from empirical observations of regression testing practice and software p
It is well-known that the radio wave propagation mechanisms inside a tunnel are different from the typical outdoor and indoor situations. Since the tunnels represent a significant type of vehicular environments, understanding the channel characteristics for the in-tunnel scenario is crucial for intelligent transport systems design. A widely used tool for simulating channel characteristics for outd
Retrospective analysis of agile projects can support identification of issues through team reflection and may enable learning and process improvements. Basing retrospectives primarily on experiences poses a risk of memory bias as people may remember events differently, which can lead to incorrect conclusions. This bias is enhanced in project retrospectives which cover a longer period compared to i
TV-on-Demand service has become one of the most popular Internet applications that continuously attracts higher user interests. With rapidly increasing user demand, the existing network conditions may not be able to ensure low start-up delay of video playback. Prefetching has been broadly investigated to cope with the start-up latency problem which is also known as user perceived latency. In this
Due to changes in the development practices at Axis Communications, towards continuous integration, faster regression testing feedback is needed. The current automated regression test suite takes approximately seven hours to run which prevents developers from integrating code changes several times a day as preferred. Therefore we want to implement a highly selective yet accurate regression testing
A complete architecture with transistor level simulation is presented for a low power analog convolutional decoder in 65 nm CMOS. The decoder core operates in the weak inversion (sub-VT) and realizes the BCJR decoding algorithm corresponding to the 4-state tail-biting trellis of a (7,5) convolutional code. The complete decoder also incorporates serial I/O digital interfaces and current mode differ
Abstract in UndeterminedThis paper presents a low-complexity, highthroughput,and configurable multiple-input multiple-output(MIMO) signal detector design solution targeting the emergingLong-Term-Evolution-Advanced (LTE-A) downlink. The detectorsupports signal detection of multiple MIMO modes, whichare spatial-multiplexing (SM), spatial-diversity (SD), and spacedivision-multiple-access (SDMA). Area
In this study, the authors investigate the resistance of Boolean functions against fast algebraic attacks and deduce a bound between fast algebraic immunity and higher-order non-linearity (it is the first time that a bound between these two cryptographic criteria is given). The authors then show that the fast algebraic immunity of the following two classes of Boolean functions is not good: (a) The
Maturity models are widely used in process improvement. The users of a maturity model should be confident that the weak points of the assessed processes can be found, and that the most valuable changes are introduced. Therefore, the evaluation of maturity models is an important activity. In this paper, a mapping study of the literature on the evaluation of maturity models is presented. Two databas
Electromagnetic vector spherical waves have been used recently to model antenna-channel interaction and the available degrees of freedom in MIMO systems. However, there are no previous accounts of a method to estimate spherical wave coefficients from channel measurements. One approach for this, using a 3D positioner, is presented and analyzed in this letter. Measurement results are presented and d
The Theory of Characteristic Modes (TCM) has been applied to design high-performance MIMO antennas for mobile terminals. However, existing studies focus on free-space (FS) performance, which is mostly irrelevant in real usage. This paper investigates the performances of two TCM-based MIMO terminal antenna designs in 7 realistic user scenarios for frequencies below 1 GHz. Full-wave simulation resul
Base station (BS) cooperative transmission is a promising technique to improve spectral efficiency of cellular systems, using which the channels become asymmetric in average gain. In this paper, we study the impact of the asymmetric channel gains on the performance of coherent cooperative transmission systems, when minimum mean square error (MMSE) and least square (LS) channel estimators are appli
Lightpath reconfiguration is a networking task that can be performed in order to improve resource utilization. The lightpath reconfiguration problem becomes nontrivial when a new set of lightpaths requires the release of resources previously seized by the (working) lightpaths currently in place, but, in order to ensure continuity of the traffic flow, the working lightpaths cannot be torn down befo
The introduction of Vehicular ad-hoc Networks (VANETs) leads to the possibility to re-evaluate many traditional functions and views of road traffic networks. The ability for vehicles and infrastructure to commu- nicate and collaborate will enable many novel solutions for problems as diverse as collision avoidance and traffic management with the view of re- ducing traffic congestion, increasing the
The demand for more efficient ciphers is a likely to sharpen with new generation of products and applications. Previous cipher designs typically focused on optimizing only one of the two parameters - hardware size or speed, for a given security level. In this paper, we present a methodology for designing a class of stream ciphers which takes into account both parameters simultaneously. We combine
