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A Beamforming Approach to Smart Grid Systems Based on Cloud Cognitive Radio
Sekchin Chang,Nagothu, Kranthimanoj,Kelley, Brian,Jamshidi, Mo M. IEEE 2014 IEEE systems journal Vol.8 No.2
<P>In this paper, we desire to use cognitive radio (CR) channels for communication among a wireless network of smart meters. However, self-interference critically limits the performance of CR systems. This is due to the coexistence of many unplanned systems simultaneously accessing the same signaling bands in an uncoordinated manner. To solve this problem, we show a beamforming approach that effectively mitigates the self-interference effects of the smart meter channel. The beamforming approach is based on minimum mean squared error (MMSE) method in smart meter systems. The MMSE beamformer usually requires accurate channel estimates and noise-plus-interference power estimates for effective mitigation of self-interference in CR systems. In this paper, we propose novel channel estimation and noise-plus-interference power estimation methodologies that efficiently exploit the preamble feature of the IEEE802.22 wireless regional area network (WRAN). Our framework is premised upon the utilization of a cloud computing smart grid infrastructure that hosts the IEEE 802.22 WRAN CR standard. The simulation results for a smart grid system with the MMSE beamformer illustrate significant improvements in system capacity and BER.</P>
Periodic Virtual Hierarchy: A Trust Model for Smart Grid Devices
Arezou Moussavi-Khalkhali,Ram Krishnan,Mo Jamshidi 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.11
Authentication among various devices that form a smart grid is a fundamental issue. Due to the large-scale, distributed, and heterogeneous nature of a smart grid, authenticating devices based on their credentials such as secret keys is often not practical. Alternatively, certificate-based trust relationships can facilitate interactions in such scenarios. Two pivotal trust relationship models, hierarchical and peer-to-peer, have been well-researched in the literature. However, the devices in a smart grid do not benefit exclusively from a single trust relationship model owing to the heterogeneous nature of its control structure. In this paper, we propose a periodic hierarchical trust relationship model suitable for real-time applications in a smart grid and robust to the single point of failure problem, which is common in hierarchies. The proposed model deploys a two-layer security authentication mechanism among different devices within those domains in which there are control hierarchies using short-term and long-term certificates, the latter of which is verified periodically.