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ABSTRACT: A novel time synchronization attack (TSA) on wide area monitoring systems in
smart grid has been identified in the first part of this paper. A cross layer
detection mechanism is proposed to combat TSA in part II of this paper. In the
physical layer, we propose a GPS carrier signal noise ratio (C/No) based
spoofing detection technique. In addition, a patch-monopole hybrid antenna is
applied to receive GPS signal. By computing the standard deviation of the C/No
difference from two GPS receivers, a priori probability of spoofing detection
is fed to the upper layer, where power system state is estimated and
controlled. A trustworthiness based evaluation method is applied to identify
the PMU being under TSA. Both the physical layer and upper layer algorithms are
integrated to detect the TSA, thus forming a cross layer mechanism. Experiment
is carried out to verify the effectiveness of the proposed TSA detection
algorithm.
04/2012;
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ABSTRACT: Many operations in power grids, such as fault detection and event location
estimation, depend on precise timing information. In this paper, a novel Time
Synchronization Attack (TSA) is proposed to attack the timing information in
smart grid. Since many applications in smart grid utilize synchronous
measurements and most of the measurement devices are equipped with global
positioning system (GPS) for precise timing, it is highly probable to attack
the measurement system by spoofing the GPS. The effectiveness of TSA is
demonstrated for three applications of phasor measurement unit (PMU) in smart
grid, namely transmission line fault detection, voltage stability monitoring
and event locationing. The validity of TSA is demonstrated by numerical
simulations.
04/2012;
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ABSTRACT: Many operations in power grids, such as fault detection and event location
estimation, depend on precise timing information. In this paper, a novel time
stamp attack (TSA) is proposed to attack the timing information in smart grid.
Since many applications in smart grid utilize synchronous measurements and most
of the measurement devices are equipped with global positioning system (GPS)
for precise timing, it is highly probable to attack the measurement system by
spoofing the GPS. The effectiveness of TSA is demonstrated for three
applications of phasor measurement unit (PMU) in smart grid, namely
transmission line fault detection, voltage stability monitoring and event
locationing.
01/2012;
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ABSTRACT: Wideband spectrum sensing in heterogenous cognitive radio networks has two significant challenges to tackle. One is the spectrum acquisition in the wideband scenario due to the limited sampling capability; the other is how to collaborate among the secondary users. Compressed spectrum sensing provides a powerful approach to acquire wideband signal. Moreover, most cooperative spectrum sensing methods assume that all the secondary users experience the same occupancy of primary users, which may be infeasible in a heterogenous spectrum environment where secondary users at different locations may be affected by different primary users. In this paper, we propose a probabilistic graphical model to represent and fuse multi-prior information from one hop neighboring secondary users. Belief propagation (BP) is used for the statistical inference of the spectrum occupancy. Numerical simulation results demonstrate that the proposed BP based cooperative compressed spectrum sensing can effectively achieve cooperation in heterogenous environments and improve performance of compressed spectrum sensing under a low sampling rate and low signal-to-noise ratio (SNR), compared with the other distributed cooperative compressed sensing methods.
IEEE Transactions on Wireless Communications 10/2011; · 2.59 Impact Factor
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ABSTRACT: System state estimation and control are important issues to ensure the stability and reliability of the smart grid system. In this paper, the problem of how to securely estimate the system state and control the smart grid is studied. In the setup studied, the sensor(s) and the controller communicate with each other through a wireless channel subjected to monitoring by an eavesdropper. The channel capacity requirement that ensures negligible information leakage to the eavesdropper about the system state and control messages is studied from the information theoretic perspective. Two scenarios with single sensor or multiple sensors are studied. Numerical simulations are used to evaluate the capacity requirement in typical configurations of the smart grid.
IEEE Transactions on Smart Grid 10/2011;
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ABSTRACT: Cognitive radio system is a very popular area in the communication community as it saves money and bandwidth by sensing the available licensed spectrum for unlicensed users. This advantage provides a promising future for the application of cognitive radio in control systems. In this paper, we propose to communicate through a cognitive radio link between the sensor and the estimator. In this way, the state estimator needs to adjust to this new communication link as the link is affected by the interruptions from primary users. We assume the emergence of primary users results in packet losses. The link is assumed to be governed by multiple semi-Markov processes each of which can capture and represent one channel in it. We derive sufficient conditions for the stability of the peak covariance process of the optimal filter. A numerical example is given to demonstrate the theorems.
American Control Conference (ACC), 2011; 08/2011
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ABSTRACT: Smart grid, equipped with modern communication infrastructures, is subject to possible cyber attacks. Particularly, false report attacks which replace the sensor reports with fraud ones may cause the instability of the whole power grid or even result in a large area blackout. In this paper, a trustiness system is introduced to the controller, who computes the trustiness of different sensors by comparing its prediction, obtained from Kalman filtering, on the system state with the reports from sensor. The trustiness mechanism is discussed and analyzed for the Linear Quadratic Regulation (LQR) controller. Numerical simulations show that the trustiness system can effectively combat the cyber attacks to smart grid.
Communications (ICC), 2011 IEEE International Conference on; 07/2011
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ABSTRACT: The communication for the control of distributed energy generation (DEG) in microgrid is discussed. Due to the requirement of realtime transmission, weak or no explicit channel coding is used for the message of system state. To protect the reliability of the uncoded or weakly encoded messages, the system dynamics are considered as a 'nature encoding' similar to convolution code, due to its redundancy in time. For systems with or without explicit channel coding, two decoding procedures based on Kalman filtering and Pearl's Belief Propagation, in a similar manner to Turbo processing in traditional data communication systems, are proposed. Numerical simulations have demonstrated the validity of the schemes, using a linear model of electric generator dynamic system.
Communications (ICC), 2011 IEEE International Conference on; 07/2011
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ABSTRACT: The social behavior in cognitive radio networks is studied using analysis tools in social networks. A recommendation system is proposed for cognitive radio, thus incurring the channel preference propagation in the corresponding random geometric network. A mean field based ordinary differential equation is used to describe the dynamics of the channel preference propagation in cognitive radio networks. The conditional distribution of random geometric graph is studied. The convergence and the steady state of the mean field equation are discussed. Numerical simulations are used to demonstrate the properties uncovered by the analysis.
Communications (ICC), 2011 IEEE International Conference on; 07/2011
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ABSTRACT: Security becomes an extremely important issue in smart grid. To maintain the
steady operation for smart power grid, massive measurement devices must be
allocated widely among the power grid. Previous studies are focused on false
data injection attack to the smart grid system. In practice, false data
injection attack is not easy to implement, since it is not easy to hack the
power grid data communication system. In this paper, we demonstrate that a
novel time stamp attack is a practical and dangerous attack scheme for smart
grid. Since most of measurement devices are equipped with global positioning
system (GPS) to provide the time information of measurements, it is highly
probable to attack the measurement system by spoofing the GPS. By employing the
real measurement data in North American Power Grid, simulation results
demonstrate the effectiveness of the time stamp attack on smart grid.
02/2011;
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ABSTRACT: The defense against the Primary User Emulation Attack (PUE) is studied in the scenario of unknown channel statistics (coined blind dogfight in spectrum). The algorithm of the adversarial bandit problem is adapted to the context of blind dogfight. Both cases of complete and partial information about the rewards of different channels are analyzed. Performance bounds are obtained subject to arbitrary channel statistics and attack policy. Several attack strategies, namely uniformly random, selectively random and maximal interception attacks, are discussed. The validity of the defense strategy is then demonstrated by numerical simulation results.
IEEE Transactions on Wireless Communications 02/2011; · 2.59 Impact Factor
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IEEE Trans. Smart Grid. 01/2011; 2:476-486.
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45st Annual Conference on Information Sciences and Systems, CISS 2011, The John Hopkins University, Baltimore, MD, USA, 23-25 March 2011; 01/2011
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45st Annual Conference on Information Sciences and Systems, CISS 2011, The John Hopkins University, Baltimore, MD, USA, 23-25 March 2011; 01/2011
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45st Annual Conference on Information Sciences and Systems, CISS 2011, The John Hopkins University, Baltimore, MD, USA, 23-25 March 2011; 01/2011
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IEICE Transactions. 01/2011; 94-B:3569-3578.
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Proceedings of the Global Communications Conference, GLOBECOM 2011, 5-9 December 2011, Houston, Texas, USA; 01/2011
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IEEE Transactions on Wireless Communications. 01/2011; 10:3020-3031.
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45st Annual Conference on Information Sciences and Systems, CISS 2011, The John Hopkins University, Baltimore, MD, USA, 23-25 March 2011; 01/2011
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45st Annual Conference on Information Sciences and Systems, CISS 2011, The John Hopkins University, Baltimore, MD, USA, 23-25 March 2011; 01/2011
