Institute for Telecommunications Research

Mawson Lakes, Australia

Institute for Telecommunications Research

Mawson Lakes, Australia
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Guo Y.,University of South Australia | Perreau S.,Institute for Telecommunications Research
International Journal of Security and Networks | Year: 2010

Mobile Ad hoc NETworks (MANETs) are vulnerable to the Denial of Service (DoS) attack. In this work, we focus on one specific DoS attack, Distributed DoS (DDoS) flooding attack. First of all, we present a quantitative model to characterise the flooding attack. We then provide analytical models of detecting flooding attack. In these models, we give an analytical framework to evaluate the number of routing control packets. At last, we design two flow based detection features to identify the flooding attacks. Both simulation and analytical results show that our proposed detection approach can detect the flooding attack accurately and effectively. Copyright © 2010 Inderscience Enterprises Ltd.

Nguyen N.H.,Institute for Telecommunications Research | Dogancay K.,Institute for Telecommunications Research | Dogancay K.,University of South Australia | Davis L.M.,Institute for Telecommunications Research
IEEE Workshop on Statistical Signal Processing Proceedings | Year: 2014

This paper considers the problem of joint transmitter waveform and receiver path optimization for target tracking by a multistatic radar incorporating one dedicated transmitter and multiple moving receiver platforms. The performance of multistatic radar, in contrast to monostatic radar, depends not only on the transmitted waveform but also on the multistatic geometry. The paper proposes a joint adaptive selection algorithm of the transmitted waveform and the receivers" heading commands to take advantage of both existing waveform-only and path-only optimization techniques. The proposed algorithm is developed to minimize the tracking mean squared error by minimizing the trace of the tracking error covariance matrix. A simulation example is presented to demonstrate the superior performance of the proposed algorithm compared to other existing waveform and heading configurations. © 2014 IEEE.

Letzepis N.,Institute for Telecommunications Research | Grant A.,Institute for Telecommunications Research | Alexander P.,Cohda Wireless | Haley D.,Cohda Wireless
Proceedings of the 2011 Australian Communications Theory Workshop, AusCTW 2011 | Year: 2011

We study joint estimation of multipath parameters from orthogonal frequency division multiplex signals transmitted over doubly dispersive mobile radio channels. In particular, we study the joint estimation of the complex gain, delay and Doppler offset of each tap of the multipath channel impulse response. For such channels, the frequency domain channel coefficients for an entire packet can be expressed as the superimposition of two-dimensional complex sinusoids. The maximum likelihood estimate requires solution of a multidimensional non-linear least squares problem, which is computationally infeasible in practice. Therefore, we propose a low complexity suboptimal solution based on iterative successive and parallel cancellation. We demonstrate via Monte Carlo simulations that the root mean squared error statistics of our estimator are very close to the Cramer-Rao lower bound of a single two-dimensional sinusoid in Gaussian noise. ©2011 IEEE.

Abramovich Y.I.,WR Systems | Johnson B.A.,Lockheed Martin | Johnson B.A.,Institute for Telecommunications Research
Proceedings of the IEEE Sensor Array and Multichannel Signal Processing Workshop | Year: 2012

We consider the problem of covariance matrix estimation for strongly non-homogeneous data (clutter), modelled as spherically invariant complex random vectors. When normalized, such data are described by a complex angular Gaussian distribution. © 2012 IEEE.

Abramovich Y.I.,WR Systems | Johnson B.A.,Lockheed Martin | Johnson B.A.,Institute for Telecommunications Research
Conference Record - Asilomar Conference on Signals, Systems and Computers | Year: 2012

In this study, we provide comparative analysis of the so-called 'threshold conditions' for conditional (deterministic, CML) and unconditional (stochastic, UML) maximum likelihood estimation. Specifically, we analyze SNR and sample support values where the accurate UML and CML DoA estimation starts to rapidly divert from the Cramér-Rao bound (CRB) due to the onset of severely erroneous DoA estimates ('outliers'). Theoretical predictions based on the recent large random matrix theory (RMT) findings are verified by Monte-Carlo simulations for sources with different levels of inter-source (spatial) or temporal correlations. © 2012 IEEE.

Haley D.,Institute for Telecommunications Research
33rd AIAA International Communications Satellite Systems Conference and Exhibition, ICSSC 2015 | Year: 2015

A major challenge for a truly global internet of things is to find a cost effective and scalable way to access sensor data and to provide control messages to sensors and devices in remote areas. As part of an Australian Space Research Program funded project, the Institute for Telecommunications Research has designed a flexible system to provide this capability from low earth orbit. One of the principal requirements of the system was to be able to handle up to 100,000 sensor terminals during a ten minute satellite pass. This is accomplished by novel waveforms and high-efficiency communication protocols resulting in a flexible and scalable satellite system that communicates with large numbers of terminals using low power and low bandwidth. This paper provides an overview of the technology and reports the results of field trials carried out in Australia and Canada. © 2015, American Institute of Aeronautics and Astronautics Inc, AIAA. All Rights Reserved.

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