946 research outputs found

    The EcoThermo project: key and innovative aspects

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    In this paper we present the most innovative aspects of the EC-FP7 EcoThermo project. The main aim of the project consists on innovating the technique of heat cost allocation in buildings with a centralized heating system, overcoming the heat cost allocator drawbacks for reliability, measurement reproducibility and traceability and contexts of applications. Given the complexity of the project, we will focus on its main aspects, such as the use of a virtual sensor to estimate the radiators heating power, the design of electronic valves fitted out with an energy harvesting system and the original wireless communication protocol

    The EcoThermo project: key and innovative aspects

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    In this paper we present the most innovative aspects of the EC-FP7 EcoThermo project. The main aim of the project consists on innovating the technique of heat cost allocation in buildings with a centralized heating system, overcoming the heat cost allocator drawbacks for reliability, measurement reproducibility and traceability and contexts of applications. Given the complexity of the project, we will focus on its main aspects, such as the use of a virtual sensor to estimate the radiators heating power, the design of electronic valves fitted out with an energy harvesting system and the original wireless communication protocol

    A novel load-balancing scheme for cellular-WLAN heterogeneous systems with cell-breathing technique

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    This paper proposes a novel load-balancing scheme for an operator-deployed cellular-wireless local area network (WLAN) heterogeneous network (HetNet), where the user association is controlled by employing a cell-breathing technique for the WLAN network. This scheme eliminates the complex coordination and additional signaling overheads between the users and the network by allowing the users to simply associate with the available WLAN networks similar to the traditional WLAN-first association, without making complex association decisions. Thus, this scheme can be easily implemented in an existing operator-deployed cellular-WLAN HetNet. The performance of the proposed scheme is evaluated in terms of load distribution between cellular and WLAN networks, user fairness, and system throughput, which demonstrates the superiority of the proposed scheme in load distribution and user fairness, while optimizing the system throughput. In addition, a cellular-WLAN interworking architecture and signaling procedures are proposed for implementing the proposed load-balancing schemes in an operator-deployed cellular-WLAN HetNet

    Moving target defense for securing smart grid communications: Architectural design, implementation and evaluation

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    Supervisory Control And Data Acquisition (SCADA) communications are often subjected to various kinds of sophisticated cyber-attacks which can have a serious impact on the Critical Infrastructure such as the power grid. Most of the time, the success of the attack is based on the static characteristics of the system, thereby enabling an easier profiling of the target system(s) by the adversary and consequently exploiting their limited resources. In this thesis, a novel approach to mitigate such static vulnerabilities is proposed by implementing a Moving Target Defense (MTD) strategy in a power grid SCADA environment, which leverages the existing communication network with an end-to-end IP Hopping technique among the trusted peer devices. This offers a proactive L3 layer network defense, minimizing IP-specific threats and thwarting worm propagation, APTs, etc., which utilize the cyber kill chain for attacking the system through the SCADA network. The main contribution of this thesis is to show how MTD concepts provide proactive defense against targeted cyber-attacks, and a dynamic attack surface to adversaries without compromising the availability of a SCADA system. Specifically, the thesis presents a brief overview of the different type of MTD designs, the proposed MTD architecture and its implementation with IP hopping technique over a Control Center–Substation network link along with a 3-way handshake protocol for synchronization on the Iowa State’s Power Cyber testbed. The thesis further investigates the delay and throughput characteristics of the entire system with and without the MTD to choose the best hopping rate for the given link. It also includes additional contributions for making the testbed scenarios more realistic to real world scenarios with multi-hop, multi-path WAN. Using that and studying a specific attack model, the thesis analyses the best ranges of IP address for different hopping rate and different number of interfaces. Finally, the thesis describes two case studies to explore and identify potential weaknesses of the proposed mechanism, and also experimentally validate the proposed mitigation alterations to resolve the discovered vulnerabilities. As part of future work, we plan to extend this work by optimizing the MTD algorithm to be more resilient by incorporating other techniques like network port mutation to further increase the attack complexity and cost

    Evaluation of the IEC 61850 Communication Solutions

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    Initially, when the IEC 61850 standard was prepared, it was intended to be used within the limits of a substation for information exchange between devices. In the course of time and due to the standard’s advantages, its concepts are nowadays used as well in other application areas of the power utility system. The IEC 61850 is based to the maximum extent on other existing communication standards (IEC/IEEE/ISO/OSI), offering among others: visualization of the real applications through the ASCI interface, standardized messages to be exchanged (GOOSE, SV), one configuration language regardless of the device (IED) type/brand, and mapping to already implemented computing protocols (MMS, TCP/IP, Ethernet). The features mentioned above lead to cost reduction, reliability, and interoperability, making the IEC61850 the dominant standard for intra- and inter-substation communication. The parts 90-1 and 90-5 of the IEC 61850 standard concern the application of the tunneling and routing method in order to extend the communication beyond the substation’s limits. Although they establish the theoretical background, it can be mentioned a lack of information regarding real applications. So, the objective of this thesis was at first to establish the communication link which will allow the communication of devices belonging to different LANs and second, the acquiring of the round trip times from the exchanged messages. The experiments were conducted by a combination of software (Hamachi) and embedded platform (BeagleBone) pinging to each other first via tunneling and next via 4G mobile network. The acquired round-trip times were used to evaluate and compare the tunneling and the 4G routing method, estimating in parallel what are the perspectives of these methods to be used for inter-substation communication.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format
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