1,786 research outputs found

    Internet of Things-aided Smart Grid: Technologies, Architectures, Applications, Prototypes, and Future Research Directions

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    Traditional power grids are being transformed into Smart Grids (SGs) to address the issues in existing power system due to uni-directional information flow, energy wastage, growing energy demand, reliability and security. SGs offer bi-directional energy flow between service providers and consumers, involving power generation, transmission, distribution and utilization systems. SGs employ various devices for the monitoring, analysis and control of the grid, deployed at power plants, distribution centers and in consumers' premises in a very large number. Hence, an SG requires connectivity, automation and the tracking of such devices. This is achieved with the help of Internet of Things (IoT). IoT helps SG systems to support various network functions throughout the generation, transmission, distribution and consumption of energy by incorporating IoT devices (such as sensors, actuators and smart meters), as well as by providing the connectivity, automation and tracking for such devices. In this paper, we provide a comprehensive survey on IoT-aided SG systems, which includes the existing architectures, applications and prototypes of IoT-aided SG systems. This survey also highlights the open issues, challenges and future research directions for IoT-aided SG systems

    Prosumer Nanogrids: A Cybersecurity Assessment

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    Nanogrids are customer deployments that can generate and inject electricity into the power grid. These deployments are based on behind-the-meter renewable energy resources and are labeled as “prosumer setups”, allowing customers to not only consume electricity, but also produce it. A residential nanogrid is comprised of a physical layer that is a household-scale electric power system, and a cyber layer that is used by manufacturers and/or grid operators to remotely monitor and control the nanogrid. With the increased penetration of renewable energy resources, nanogrids are at the forefront of a paradigm shift in the operational landscape and their correct operation is vital to the electric power grid. In this paper, we perform a cybersecurity assessment of a state-of-the art residential nanogrid deployment. For this purpose, we deployed a real-world experimental nanogrid setup that is based on photovoltaic (PV) generation. We analyzed the security and the resiliency of this system at both the cyber and physical layers. While we noticed improvements in the cybersecurity measures employed in the current nanogrid compared to previous generations, there are still major concerns. Our experiments show that these concerns range from exploiting well-known protocols, such as Secure Shell (SSH) and Domain Name Service (DNS), to the leakage of confidential information, and major shortcomings in the software updating mechanism. While the compromise of multiple nanogrids can have a negative effect on the entire power grid, we focus our analysis on individual households and have determined through Simulink-based simulations the economic loss of a compromised deployment.National Science Foundation under Grant 1850406

    Experimental design for a next generation residential gateway

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    Puolella eurooppalaisista kotitalouksista on laajakaistaliittymÀ. YleensÀ kÀyttÀjÀ kytkeytyy ulkoiseen verkkoon kotireitittimen avulla (residential gateway). Internet-yhteyden ja IP-perustaisten palveluiden kuten VoIP- ja IPTV-palveluiden lisÀksi kotireititin muodostaa kotiverkon ytimen kodin verkkolaitteiden liittyessÀ siihen. Kotiverkkojen lukumÀÀrÀn ja koon kasvun seurauksena kotiverkoissa voidaan tunnistaa kolme ongelmaa. EnsinnÀkin kotiverkkojen hallinta on haastavaa kotiverkossa tuettavien verkkotekniikoiden ja laitteiden mÀÀrÀn kasvaessa. Toiseksi sisÀllönhallinta. on monimutkaistunut kÀyttÀjien luodessa ja kuluttaessa yhÀ enemmÀn sisÀltöÀ. Kolmanneksi uudet verkkoperustaiset tekniikat kuten sÀhköisen terveydenhuollon ratkaisut (e-health) integroituvat usein heikosti olemassa olevien kotiverkkolaitteiden kanssa. TÀssÀ diplomityössÀ edellÀ mainittuihin ongelmiin pyritÀÀn löytÀmÀÀn yhtenÀinen ratkaisu kotireititintÀ apuna kÀyttÀen. TyössÀ analysoidaan uudentyyppisen kotireitittimen vaatimuksia kÀyttÀmÀllÀ hyvÀksi joukkoa kÀyttötapauksia. Vaativuusanalyysin perusteella luodaan malli, joka sisÀltÀÀ seuraavat pÀÀkomponentit. (i) Virtuaalisointitekniikkaan pohjautuva kotireititinarkkitehtuuri. (ii) Kotireititinperustainen mekanismi yhteisöverkostoiden pystyttÀmiseen kotiverkkojen vÀlillÀ. (iii) Hajautettu tiedostojÀrjestelmÀ yhteisöverkkojen pystyttÀmiseksi ja parannetun sisÀllönhallinnan ja sisÀllön jakamisen mahdollistamiseksi. (iv) Mekanismeja joiden avulla vierailevat kÀyttÀjÀt voivat hyödyntÀÀ muiden kÀyttÀjien kotireitittimien resursseja. TyössÀ. toteutetaan em. ydintoimintoja laaditun mallin perusteella ja toteutuksen toimivuus verifioidaan kÀyttötapauksiin perustuvalla testauksellaToday over half of the European homes have a broadband Internet connection. Typically, this connection is enabled through a residential gateway device at the users' premises. In addition to facilitating triple play services, this gateway also forms the core of users' home networks by connecting their network-enabled devices. While the number and the size of such home networks keep on increasing, three major problems can be identified in current systems. First, home network management is getting increasingly complex, and a growing number of networking technologies and connected devices must be supported and managed. Second, content management has become difficult. Users are generating an increasing amount of content and this content is stored (and sometimes shared) in an almost anarchical manner across different home network devices as well as online. Third, new network-enabled services, such as e-health systems, are emerging, but are typically poorly integrated into existing home networks. There is a clear need for home networking solutions that address these problems. In this thesis, we adopt a gateway-centric approach to address these problems in a unified manner. We concretise the requirements for a next generation residential gateway by analysing a set of future home networking use cases. These requirements serve as input to our gateway system design. In summary, our design includes the following main components. (i) A residential gateway architecture based on virtualization. This enables new features and new ways to implement the other components of our design. (ii) A gateway-based mechanism to set up community networks between different home networks. (iii) A distributed file system to establish community networks and to enable improved content management and sharing. (iv) Mechanisms for visiting gateway users to utilize other users' gateway resources. We implement these core functionalities and develop a proof-of concept prototype. We successfully validate our prototype through use case driven testbed experiments. Finally, we believe that the insights gained from this study and the prototype implementations are important overall contributions that can be used in the future research to further explore the limitations and opportunities of this gateway-centric approach

    Ethernet - a survey on its fields of application

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    During the last decades, Ethernet progressively became the most widely used local area networking (LAN) technology. Apart from LAN installations, Ethernet became also attractive for many other fields of application, ranging from industry to avionics, telecommunication, and multimedia. The expanded application of this technology is mainly due to its significant assets like reduced cost, backward-compatibility, flexibility, and expandability. However, this new trend raises some problems concerning the services of the protocol and the requirements for each application. Therefore, specific adaptations prove essential to integrate this communication technology in each field of application. Our primary objective is to show how Ethernet has been enhanced to comply with the specific requirements of several application fields, particularly in transport, embedded and multimedia contexts. The paper first describes the common Ethernet LAN technology and highlights its main features. It reviews the most important specific Ethernet versions with respect to each application field’s requirements. Finally, we compare these different fields of application and we particularly focus on the fundamental concepts and the quality of service capabilities of each proposal

    System Design of Internet-of-Things for Residential Smart Grid

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    Internet-of-Things (IoTs) envisions to integrate, coordinate, communicate, and collaborate real-world objects in order to perform daily tasks in a more intelligent and efficient manner. To comprehend this vision, this paper studies the design of a large scale IoT system for smart grid application, which constitutes a large number of home users and has the requirement of fast response time. In particular, we focus on the messaging protocol of a universal IoT home gateway, where our cloud enabled system consists of a backend server, unified home gateway (UHG) at the end users, and user interface for mobile devices. We discuss the features of such IoT system to support a large scale deployment with a UHG and real-time residential smart grid applications. Based on the requirements, we design an IoT system using the XMPP protocol, and implemented in a testbed for energy management applications. To show the effectiveness of the designed testbed, we present some results using the proposed IoT architecture.Comment: 10 pages, 6 figures, journal pape

    Network and service monitoring in heterogeneous home networks

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    Home networks are becoming dynamic and technologically heterogeneous. They consist of an increasing number of devices which offer several functionalities and can be used for many different services. In the home, these devices are interconnected using a mixture of networking technologies (for example, Ethernet, Wifi, coaxial cable, or power-line). However, interconnecting these devices is often not easy. The increasing heterogeneity has led to significant device- and service-management complexity. In addition, home networks provide a critical "last meters" access to the public telecom and Internet infrastructure and have a dramatic impact on to the end-to-end reliability and performance of services from these networks. This challenges service providers not only to maintain a satisfactory quality of service level in such heterogeneous home networks, but also to remotely monitor and troubleshoot them. The present thesis work contributes research and several solutions in the field of network and service monitoring in home networks, mainly in three areas: (1) providing automatic device- and service-discovery and configuration, (2) remote management, and (3) providing quality of service (QoS). With regard to the first area, current service discovery technology is designed to relieve the increasing human role in network and service administration. However, the relevant Service Discovery Protocols (SDPs) are lacking crucial features namely: (1) they are not platform- and network-independent, and (2) they do not provide sufficient mechanisms for (device) resource reservation. Consequently, devices implementing different SDPs cannot communicate with each other and share their functionalities and resources in a managed way, especially when they use different network technologies. As a solution to the first problem, we propose a new proxy server architecture that enables IP-based devices and services to be discovered on non-IP based network and vice versa. We implemented the proxy architecture using UPnP respectively Bluetooth SDP as IP- and non-IP-based SDPs. The proxy allows Bluetooth devices and UPnP control points to discover, access, and utilize services located on the other network. Validation experiments with the proxy prototype showed that seamless inter-working can be achieved keeping all proxy functionalities on a single device, thus not requiring modification of currently existing UPnP and Bluetooth end devices. Although the proxy itself taxes the end-to-end performance of the service, it is shown to be still acceptable for an end user. For mitigating resource conflicts in SDPs, we propose a generic resource reservation scheme with properties derived from common SDP operation. Performance studies with a prototype showed that this reservation scheme significantly improves the scalability and sustainability of service access in SDPs, at a minor computational cost. With regard to the second area, it is known that the end-to-end quality of Internet services depends crucially on the performance of the home network. Consequently, service providers require the ability to monitor and configure devices in the home network, behind the home gateway (HG). However, they can only put limited requirements to these off-the-shelf devices, as the consumer electronics market is largely outside their span of control. Therefore they have to make intelligent use of the given device control and management protocols. In this work, we propose an architecture for remote discovery and management of devices in a highly heterogeneous home network. A proof-of-concept is developed for the remote management of UPnP devices in the home with a TR-069/UPnP proxy on the HG. Although this architecture is protocol specific, it can be easily adapted to other web-services based protocols. Service providers are also asking for diagnostic tools with which they can remotely troubleshoot the home networks. One of these tools should be able to gather information about the topology of the home network. Although topology discovery protocols already exist, nothing is known yet about their performance. In this work we propose a set of key performance indicators for home network topology discovery architectures, and how they should be measured. We applied them to the Link-Layer Topology Discovery (LLTD) protocol and the Link-Layer Discovery Protocol (LLDP). Our performance measurement results show that these protocols do not fulfill all the requirements as formulated by the service providers. With regard to the third area, current QoS solutions are mostly based on traffic classification. Because they need to be supported by all devices in the network, they are relatively expensive for home networks. Furthermore, they are not interoperable between different networking technologies. Alternative QoS provision techniques have been proposed in the literature. These techniques require end-user services to pragmatically adapt their properties to the actual condition of the network. For this, the condition of the home network in terms of its available bandwidth, delay, jitter, etc., needs to be known in real time. Appropriate tools for determining the available home network resources do not yet exist. In this work we propose a new method to probe the path capacity and available bandwidth between a server and a client in a home network. The main features of this method are: (a) it does not require adaptation of existing end devices, (b) it does not require pre-knowledge of the link-layer network topology, and (c) it is accurate enough to make reliable QoS predictions for the most relevant home applications. To use these predictions for effective service- or content-adaptation or admission control, one should also know how the state of the home network is expected to change immediately after the current state has been probed. However, not much is known about the stochastic properties of traffic in home networks. Based on a relatively small set of traffic observations in several home networks in the Netherlands, we were able to build a preliminary model for home network traffic dynamics

    Correlated multi-streaming in distributed interactive multimedia systems

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    Distributed Interactive Multimedia Environments (DIMEs) enable geographically distributed people to interact with each other in a joint media-rich virtual environment for a wide range of activities, such as art performance, medical consultation, sport training, etc. The real-time collaboration is made possible by exchanging a set of multi-modal sensory streams over the network in real time. The characterization and evaluation of such multi-stream interactive environments is challenging because the traditional Quality of Service metrics (e.g., delay, jitter) are limited to a per stream basis. In this work, we present a novel ???Bundle of Streams??? concept to de???ne correlated multi-streams in DIMEs and present new cyber-physical, spatio-temporal QoS metrics to measure QoS over bundle of streams. We realize Bundle of Streams concept by presenting a novel paradigm of Bundle Streaming as a Service (SAS). We propose and develop SAS Kernel, a generic, distributed, modular and highly ???exible streaming kernel realizing SAS concept. We validate the Bundle of Streams model by comparing the QoS performance of bundle of streams over different transport protocols in a 3D tele-immersive testbed. Also, further experiments demonstrate that the SAS Kernel incurs low overhead in delay, CPU, and bandwidth demands
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