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

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

A Structured Hardware/Software Architecture for Embedded Sensor Nodes

Owing to the limited requirement for sensor processing in early networked sensor nodes, embedded software was generally built around the communication stack. Modern sensor nodes have evolved to contain significant on-board functionality in addition to communications, including sensor processing, energy management, actuation and locationing. The embedded software for this functionality, however, is often implemented in the application layer of the communications stack, resulting in an unstructured, top-heavy and complex stack. In this paper, we propose an embedded system architecture to formally specify multiple interfaces on a sensor node. This architecture differs from existing solutions by providing a sensor node with multiple stacks (each stack implements a separate node function), all linked by a shared application layer. This establishes a structured platform for the formal design, specification and implementation of modern sensor and wireless sensor nodes. We describe a practical prototype of an intelligent sensing, energy-aware, sensor node that has been developed using this architecture, implementing stacks for communications, sensing and energy management. The structure and operation of the intelligent sensing and energy management stacks are described in detail. The proposed architecture promotes structured and modular design, allowing for efficient code reuse and being suitable for future generations of sensor nodes featuring interchangeable components

Mesh-Mon: a Monitoring and Management System for Wireless Mesh Networks

A mesh network is a network of wireless routers that employ multi-hop routing and can be used to provide network access for mobile clients. Mobile mesh networks can be deployed rapidly to provide an alternate communication infrastructure for emergency response operations in areas with limited or damaged infrastructure. In this dissertation, we present Dart-Mesh: a Linux-based layer-3 dual-radio two-tiered mesh network that provides complete 802.11b coverage in the Sudikoff Lab for Computer Science at Dartmouth College. We faced several challenges in building, testing, monitoring and managing this network. These challenges motivated us to design and implement Mesh-Mon, a network monitoring system to aid system administrators in the management of a mobile mesh network. Mesh-Mon is a scalable, distributed and decentralized management system in which mesh nodes cooperate in a proactive manner to help detect, diagnose and resolve network problems automatically. Mesh-Mon is independent of the routing protocol used by the mesh routing layer and can function even if the routing protocol fails. We demonstrate this feature by running Mesh-Mon on two versions of Dart-Mesh, one running on AODV (a reactive mesh routing protocol) and the second running on OLSR (a proactive mesh routing protocol) in separate experiments. Mobility can cause links to break, leading to disconnected partitions. We identify critical nodes in the network, whose failure may cause a partition. We introduce two new metrics based on social-network analysis: the Localized Bridging Centrality (LBC) metric and the Localized Load-aware Bridging Centrality (LLBC) metric, that can identify critical nodes efficiently and in a fully distributed manner. We run a monitoring component on client nodes, called Mesh-Mon-Ami, which also assists Mesh-Mon nodes in the dissemination of management information between physically disconnected partitions, by acting as carriers for management data. We conclude, from our experimental evaluation on our 16-node Dart-Mesh testbed, that our system solves several management challenges in a scalable manner, and is a useful and effective tool for monitoring and managing real-world mesh networks

Gestión inteligente de sistemas de distribución de agua

The United Nations predicts that the world's population in 2050 will reach 9.7 billion people. This exponential growth will mean an increase in the global demand for water available for human consumption. In addition, the advance of climate change is causing the occurrence of more frequent droughts, especially in arid and semi-arid areas. Indirectly, this means an increase in the costs associated with water transport and purification, as water must be drawn from sources that are increasingly distant from the points of consumption and the quality is getting worse. The traditional management of urban water supply is changing towards a more sustainable model aimed at an efficient use of resources (water, energy, labour) that not only reduces management costs but is also more environmentally friendly. This transformation is taking place due to the development of other transversal disciplines (cloud computing, communication systems, Big Data, electronics, etc.) applied to many fields of science, which applied to water management, can bring considerable benefits. Furthermore, to achieve intelligent management of a water supply network, it is necessary to rely on current tools that provide objective knowledge of the system. For example, geographic information systems (GIS) together with hydraulic models serve as a georeferenced database where the behaviour of any hydraulic network in different scenarios can be simulated. The Internet of Things (IoT) allows the connection of a network of sensors to know the main hydraulic variables at any time, providing key information for hydraulic models to faithfully reproduce the behaviour of modelled systems in real time. Digitalisation itself favours the use of information and communication technologies (ICT) to convert traditional management into smart management. For these reasons, new studies are needed to assess the potential and applicability of these new tools. This thesis is organised in 6 chapters focused on the development and application of a decision support system that allow the manager of a water supply network to make decisions based on data recorded on real-time. All the tools developed throughout this thesis have been tested in a real water supply network located in the south of Spain, managed by the Provincial Water Company of Cordoba (EMPROACSA). Chapter 1 shows the trajectory of urban supply management: explaining the starting point and where it is expected to achieve. Then, Chapter 2 describes the main objective and the specific objectives of this thesis, as well as the structure of this document. Chapter 3 presents a methodology that serves as a basis for starting the digitisation process in water supply networks. The system developed is based on three pillars: the geographic information system, the hydraulic model, and the application for mobile devices. The geographic information system provides a georeferenced database of the infrastructures that compose the hydraulic network; the hydraulic model simulates the response of the network to different operation scenarios; and finally, the mobile application facilitates the feedback of the system to keep it always up to date with changes in the systems. One of the distinguishing features of this work is the use of free software (Qgis, Epanet and Google My Maps) in all stages, which fosters digitisation in supply companies with a low budget. Chapter 4 develops an early warning system based on water pressure monitoring. The communication node developed ad-hoc for this work, sends water pressure data to the cloud, where users can visualise them with a device with an internet connection. Among its advantages are its low cost, it allows the use of different communication systems and has a high autonomy powered by batteries, which makes it well adapted to supply systems. The proposed monitoring system detects failures in the network due to pressure drops, alerting managers of the affected zone. Chapter 5 explains the decision support tool developed to deal with failures in water transmission networks. The web platform that supports this tool is divided into 3 independent modules: fault detection, alerts, and fault repair. The first module is responsible for detecting, geolocating and classifying faults in the hydraulic network using the information recorded in real time by the pressure monitoring system described in the previous chapter. The second module is responsible for sending alerts selectively to the workers in the area of the failure. Finally, the third module estimates, applying the hydraulic model, the maximum time that the manager has to fix failures, avoiding supply cuts using the water stored in regulation tanks when the failure occurs. The fault detection and classification module has demonstrated a 95% accuracy when applied to a real case. Chapter 6 contains the general conclusions of the thesis, as well as possible lines of future work. In summarise, water management is experiencing a paradigm shift. This transformation requires sufficiently mature technologies to ensure good results. Therefore, studies are needed that not only advance towards smart management, but also evaluate the tools available now and their integration into the current management model. This thesis presents a decision support system applied to supply networks, which help managers to make decisions based on objective information, not on intuition or experience. The use of open-source software and hardware in all the developments of this thesis must be emphasised. This specific feature allows the adoption of the methodologies proposed by water companies, regardless of size or financial resources, enabling the whole system or only part of it to be adapted to the operation of the company.Las Naciones Unidas prevén que la población mundial en 2050 alcanzará los 9.700 millones de personas. Este crecimiento exponencial supondrá un aumento de la demanda global de agua disponible para el consumo humano. Además, el avance del cambio climático está provocando la aparición de sequías más frecuentes, especialmente en las zonas áridas y semiáridas. Indirectamente, esto supone un aumento de los costes asociados al transporte y la depuración del agua, ya que hay que extraerla de fuentes cada vez más alejadas de los puntos de consumo y la calidad es cada vez peor. La gestión tradicional del abastecimiento de agua en las ciudades está cambiando hacia un modelo más sostenible orientado a un uso eficiente de los recursos (agua, energía, mano de obra) que además de reducir los costes de gestión, es más respetuoso con el medio ambiente. Esta transformación se está produciendo gracias al desarrollo de otras disciplinas transversales (computación en la nube, sistemas de comunicación, Big Data, electrónica, etc.) aplicadas a diversos campos de la ciencia, que aplicadas a la gestión del agua, pueden aportar considerables beneficios. Además, para conseguir una gestión inteligente de una red de abastecimiento de agua, es necesario apoyarse en herramientas actuales que proporcionen un conocimiento objetivo del sistema. Por ejemplo, los sistemas de información geográfica (SIG) junto con los modelos hidráulicos sirven como base de datos georreferenciada donde se puede simular el comportamiento de cualquier red hidráulica en diferentes escenarios. El Internet de las Cosas (IoT) permite la conexión de una red de sensores para conocer las principales variables hidráulicas en cada momento, aportando información clave para que los modelos hidráulicos reproduzcan fielmente el comportamiento de los sistemas modelizados en tiempo real. La propia digitalización favorece el uso de las tecnologías de la información y la comunicación (TIC) para convertir la gestión tradicional en una gestión inteligente. Por estas razones, son necesarios nuevos estudios para evaluar el potencial y la aplicabilidad de estas nuevas herramientas. Esta tesis se organiza en 6 capítulos centrados en el desarrollo y aplicación de un sistema de apoyo a la decisión que permita al gestor de una red de abastecimiento de agua tomar decisiones basadas en datos registrados en tiempo real. Todas las herramientas desarrolladas a lo largo de esta tesis han sido probadas en una red real de abastecimiento de agua situada en el sur de España, gestionada por la Empresa Provincial de Aguas de Córdoba (EMPROACSA). El capítulo 1 muestra la trayectoria de la gestión del abastecimiento urbano: explicando el punto de partida y hacia dónde se espera llegar. A continuación, el capítulo 2 describe el objetivo principal y los objetivos específicos de esta tesis, así como la estructura de este documento. El capítulo 3 presenta una metodología que sirve de base para iniciar el proceso de digitalización de las redes de abastecimiento de agua. El sistema desarrollado se basa en tres pilares: el sistema de información geográfica, el modelo hidráulico y la aplicación para dispositivos móviles. El sistema de información geográfica proporciona una base de datos georreferenciada de las infraestructuras que componen la red hidráulica; el modelo hidráulico simula la respuesta de la red ante diferentes escenarios de operación; y, por último, la aplicación móvil facilita la retroalimentación del sistema para mantenerlo siempre actualizado con los cambios en los sistemas. Uno de los rasgos distintivos de este trabajo es el uso de software libre (Qgis, Epanet y Google My Maps) en todas las etapas, lo que favorece la digitalización en empresas de abastecimiento con bajo presupuesto. El capítulo 4 desarrolla un sistema de alerta temprana basado en la monitorización de la presión del agua. El nodo de comunicación desarrollado ad-hoc para este trabajo, envía los datos de la presión del agua a la nube, donde los usuarios pueden visualizarlos con un dispositivo con conexión a internet. Entre sus ventajas están su bajo coste, permite el uso de diferentes sistemas de comunicación y tiene una gran autonomía alimentada por baterías, lo que hace que se adapte bien a los sistemas de abastecimiento. El sistema de monitorización propuesto detecta fallos en la red por caídas de presión, alertando a los gestores de la zona afectada. El capítulo 5 explica la herramienta de apoyo a la toma de decisiones desarrollada para hacer frente a las averías en las redes de abastecimiento en alta. La plataforma web, que soporta esta herramienta, se divide en 3 módulos independientes: detección de averías, alertas y reparación de averías. El primer módulo se encarga de detectar, geolocalizar y clasificar las averías en la red hidráulica a partir de la información registrada en tiempo real por el sistema de monitorización de presiones descrito en el capítulo anterior. El segundo módulo se encarga de enviar alertas de forma selectiva a los trabajadores de la zona de la avería. Por último, el tercer módulo estima, aplicando el modelo hidráulico, el tiempo máximo del que dispone el gestor para solucionar las averías, evitando los cortes de suministro con el agua almacenada en los depósitos de regulación cuando se produce la avería. El módulo de detección y clasificación de averías ha demostrado una precisión del 95% cuando se aplica a un caso real. El capítulo 6 contiene las conclusiones generales de la tesis, así como posibles líneas de trabajo futuras. En resumen, la gestión del agua está experimentando un cambio de paradigma. Esta transformación requiere tecnologías suficientemente maduras para garantizar buenos resultados. Por ello, son necesarios estudios que no sólo avancen hacia una gestión inteligente, sino que evalúen las herramientas disponibles en la actualidad y su integración en el modelo de gestión actual. Esta tesis presenta un sistema de apoyo a la decisión aplicado a las redes de suministro de agua, que ayuda a los gestores a tomar decisiones basadas en información objetiva y no en la intuición o la experiencia. Cabe destacar el uso de software y hardware de código abierto en todos los desarrollos de esta tesis. Esta particularidad permite la adopción de las metodologías propuestas por las empresas de agua, independientemente de su tamaño o recursos financieros, permitiendo adaptar todo el sistema o sólo una parte de él al funcionamiento de la empresa

A Radio Link Quality Model and Simulation Framework for Improving the Design of Embedded Wireless Systems

Despite the increasing application of embedded wireless systems, developers face numerous challenges during the design phase of the application life cycle. One of the critical challenges is ensuring performance reliability with respect to radio link quality. Specifically, embedded links experience exaggerated link quality variation, which results in undesirable wireless performance characteristics. Unfortunately, the resulting post-deployment behaviors often necessitate network redeployment. Another challenge is recovering from faults that commonly occur in embedded wireless systems, including node failure and state corruption. Self-stabilizing algorithms can provide recovery in the presence of such faults. These algorithms guarantee the eventual satisfaction of a given state legitimacy predicate regardless of the initial state of the network. Their practical behavior is often different from theoretical analyses. Unfortunately, there is little tool support for facilitating the experimental analysis of self-stabilizing systems. We present two contributions to support the design phase of embedded wireless system development. First, we provide two empirical models that predict radio-link quality within specific deployment environments. These models predict link performance as a function of inter-node distance and radio power level. The models are culled from extensive experimentation in open grass field and dense forest environments using all radio power levels and covering up to the maximum distances reachable by the radio. Second, we provide a simulation framework for simulating self-stabilizing algorithms. The framework provides three feature extensions: (i) fault injection to study algorithm behavior under various fault scenarios, (ii) automated detection of non-stabilizing behavior; and (iii) integration of the link quality models described above. Our contributions aim at avoiding problems that could result in the need for network redeployment

Estimating Fire Weather Indices via Semantic Reasoning over Wireless Sensor Network Data Streams

Wildfires are frequent, devastating events in Australia that regularly cause significant loss of life and widespread property damage. Fire weather indices are a widely-adopted method for measuring fire danger and they play a significant role in issuing bushfire warnings and in anticipating demand for bushfire management resources. Existing systems that calculate fire weather indices are limited due to low spatial and temporal resolution. Localized wireless sensor networks, on the other hand, gather continuous sensor data measuring variables such as air temperature, relative humidity, rainfall and wind speed at high resolutions. However, using wireless sensor networks to estimate fire weather indices is a challenge due to data quality issues, lack of standard data formats and lack of agreement on thresholds and methods for calculating fire weather indices. Within the scope of this paper, we propose a standardized approach to calculating Fire Weather Indices (a.k.a. fire danger ratings) and overcome a number of the challenges by applying Semantic Web Technologies to the processing of data streams from a wireless sensor network deployed in the Springbrook region of South East Queensland. This paper describes the underlying ontologies, the semantic reasoning and the Semantic Fire Weather Index (SFWI) system that we have developed to enable domain experts to specify and adapt rules for calculating Fire Weather Indices. We also describe the Web-based mapping interface that we have developed, that enables users to improve their understanding of how fire weather indices vary over time within a particular region.Finally, we discuss our evaluation results that indicate that the proposed system outperforms state-of-the-art techniques in terms of accuracy, precision and query performance.Comment: 20pages, 12 figure