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

Software controlled low cost thermoelectric energy harvester for ultra-low power wireless sensor nodes

General hardware architecture of an energy-harvested wireless sensor network node (EH-WSN) can be divided into power, sensing, computing and communication subsystems. Interrelation between these subsystems in combination with constrained energy supply makes design and implementation of EH-WSN a complex and challenging task. Separation of these subsystems into distinct hardware modules simplifies the design process and makes the architecture and software more generic, leading to more flexible solutions. From the other hand, tightly coupling these subsystems gives more room for optimizations at the price of increased complexity of the hardware and software. Additional engineering effort could be justified by a smaller, cheaper hardware, and more energy-efficient a wireless sensor node. The aim of this paper is to push further technical and economical boundaries related to EH-WSN by proposing a novel architecture which – by tightly coupling software and hardware of power, computing, and communication subsystems – allows the wireless sensor node to be powered by a thermoelectric generator working with about 1.5°C temperature difference while keeping the cost of all electronic components used to build such a node below 9 EUR (in volume)

Smart system for control and monitoring of swimming pools

Internet of Things emerged as one of the biggest promises of evolutional technologies, being increasingly identified as a dependency of the quotidian life. It is based on the connection of many devices that aims to simplify daily activities providing monitorization activities, remote control or the development of smart environments that aims to reduce the need of human intervention. Taking into consideration that the incorrect use of fresh water in daily activities is nowadays a big concern as well as the need to keep track of water quality in order to inform the user about potential risk situations, this dissertation proposes the appliance of IoT concept with a new scheme for monitoring and control of swimming pools quality through a low-cost system based on wireless sensor and actuator networks, which can reduce the requirements of human in the swimming pool maintenance. The main purpose of this system is to provide resources savings for the final user in financial and natural resources, contributing to a more sustainable environment. An Android mobile application was developed, providing users to monitor and remotely control swimming pool’s parameters in real time, providing an easier data analysis and the definition of thresholds to each parameter in order to notify the user when the imposed limits are exceeded. The remote control of some devices is possible to do in two modes: manually or automatically. The developed solution presents a system designed and implemented with a simple architecture and high efficiency level, with practical demonstrations of the obtained results.A Internet das Coisas surgiu como uma das maiores promessas tecnológicas, sendo cada vez mais identificada como um fator de dependência no quotidiano. Esta baseia-se na conexão de dispositivos capazes de proporcionar atividades de monitorização, controlo remoto ou desenvolvimento de ambientes inteligentes que visam reduzir a necessidade da intervenção humana. Tendo em conta o uso incorreto de recursos como a água em atividades do dia-a-dia, cada vez mais existe uma grande preocupação e necessidade de acompanhar a qualidade da água para manter os seus utilizadores informados sobre possíveis situações de risco. Esta dissertação propõe a aplicação do conceito da Internet das Coisas com um novo esquema para monitorização e controlo da qualidade das piscinas, através de um sistema de baixo custo baseado numa rede sem fios de sensores e atuadores, reduzindo a requisição de recursos humanos na manutenção de piscinas. O principal objetivo deste sistema é proporcionar a poupança de recursos económicos e naturais aos seus utilizadores, contribuindo para um ambiente mais sustentável. Foi desenvolvida uma aplicação Android, que possibilita a monitorização e controlo remoto de dados recolhidos das piscinas em tempo real, fornecendo uma análise de dados e a definição de limites para cada um dos parâmetros, de modo a notificar o utilizador quando os limites definidos forem excedidos. O controlo de alguns dispositivos é possível através de dois modos: manualmente e automaticamente. A solução desenvolvida apresenta um sistema desenhado e implementado com uma arquitetura simples um alto nível de eficiência, com demonstrações práticas e resultados obtidos

Internet of Things From Hype to Reality

The Internet of Things (IoT) has gained significant mindshare, let alone attention, in academia and the industry especially over the past few years. The reasons behind this interest are the potential capabilities that IoT promises to offer. On the personal level, it paints a picture of a future world where all the things in our ambient environment are connected to the Internet and seamlessly communicate with each other to operate intelligently. The ultimate goal is to enable objects around us to efficiently sense our surroundings, inexpensively communicate, and ultimately create a better environment for us: one where everyday objects act based on what we need and like without explicit instructions

Spectrum Sharing and Interference in Smart Homes

Internet of Things networks using Zigbee are very popular in smart homes. However, Zigbee networks are vulnerable to the interference of Wi-Fi networks because they share the same 2.4 GHz Industrial, Scientific, and Medical radio frequency band. Studies have shown that weaker Zigbee signals might be significantly interfered by stronger Wi-Fi signals. This type of interference may cause severe problems when these types of networks coexist in an indoor environment such as in a smart home. In this thesis, the performance of a Zigbee network with and without the presence of a Wi-Fi network has been evaluated in an apartment-based indoor environment mimicking a smart home. The experimental results are obtained and analyzed in terms of received signal strength indicator, packet delay, packet drop rate, and loopback throughput by changing operating channels, distances between Zigbee and Wi-Fi devices, transmission intervals of Zigbee packets, Zigbee transmit power, and Zigbee packet lengths

Performance assessment of mobility solutions for IPv6-based healthcare wireless sensor networks

This thesis focuses on the study of mobile wireless sensor networks applied to healthcare scenarios. The promotion of better quality-of-life for hospitalized patients is addressed in this research work with a solution that can help these patients to keep their mobility (if possible). The solution proposed allows remote monitoring and control of patients’ health in real-time and without interruptions. Small sensor nodes able to collect and send wirelessly the health parameters allow for the control of the patients' health condition. A network infrastructure, composed by several access points, allows the connection of the sensor nodes (carried by the patients) to remote healthcare providers. To ensure continuous access to sensor nodes special attention should be dedicated to manage the transition of these sensor nodes between different access points’ coverage areas. The process of changing an access point attachment of a sensor node is called handover. In that context, this thesis proposes a new handover mechanism that can ensure continuous connection to mobile sensor nodes in a healthcare wireless sensor network. Due to the limitations of sensor nodes’ resources, namely available energy (these sensor nodes are typically powered by small batteries), the proposed mechanism pays a special attention in the optimization of energy consumption. To achieve this optimization, part of this work is dedicated to the construction of a small sensor node. The handover mechanism proposed in this work is called Hand4MAC (handover mechanism for MAC layer). This mechanism is compared with other mechanisms commonly used in handover management. The Hand4MAC mechanism is deployed and validated through by simulation and in a real testbed. The scenarios used for the validation reproduces a hospital ward. The performance evaluation is focused in the percentage of time that senor nodes are accessible to the network while traveling across several access points’ coverage areas and the energy expenditures in handover processes. The experiments performed take into account various parameters that are the following: number of sent messages, number of received messages, multicast message usage, energy consumption, number of sensor nodes present in the scenario, velocity of sensor nodes, and time-to-live value. In both simulation and real testbed, the Hand4MAC mechanism is shown to perform better than all the other handover mechanisms tested. In this comparison it was only considered the most promising handover mechanisms proposed in the literature.Fundação para a Ciência e a Tecnologia (FCT