418 research outputs found

    On the use of IEEE 802.15.4/ZigBee as federating communication protocols for Wireless Sensor Networks

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    Tese de mestrado. Redes e Serviços de Comunicação. Faculdade de Engenharia. Universidade do Porto, Instituto Superior de Engenharia. 200

    Design of a Low-Power Automatic Wireless Multi-Logger Networking Device

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    Virtually every industry and discipline (e.g., mining, pharmaceutical, construction, agriculture, reclamation, etc.) is finding applications for wireless data acquisition for monitoring and managing processes and resources. Two sectors, namely agriculture and environmental research, are seeking ways to obtain distributed soil and plant measurements over larger areas like a watershed or large fields rather than a single site of intensive instrumentation (i.e., a weather station). Wireless sensor networks and remote sensing have been explored as a means to satisfy this need. Commercial products are readily available that have remote wireless options to support distributed senor networking. However, these systems have been designed with a field engineer or technician as the target end-user. Equipment and operating costs, device specific programming languages, and complex wireless configuration schemes have impeded the adoption of large-scale, multi-node wireless systems in these fields. This report details the development of an easy-to-use, ultra-low power wireless datalogger incorporating a scalable, intelligent data collection and transmission topology. The final product can interface to various sensor types including SDI-12 and uses an LCD display to help simplify device setup

    Embedded Dual Band Rfid Based Blood Glucose Monitoring System For Internet Of Medical Things

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    Manually recorded health information could lead to errors such as inaccurate patient identification and mismatch patient data that could seriously affect patient safety. In order to reduce the risks of error for patients with diabetes, a new design of wireless blood glucose monitoring system with the embedment of dual band RFID for Internet of Medical Things is being developed. Using this method, passive RFID allows short-range communication to read automatically the patient identification number and active RFID extends long-range communication for recording and monitoring blood glucose data through multi-hop WSN. The work presented in this thesis contributes mainly to the embedded system and its application in healthcare to reduce the burden of recording, tracing and monitoring the patient‘s data by embedding blood glucose sensor, passive RFID, active RFID, WSN, M2M and IoMT into a single platform. A new design concept is established for the patient identification mechanism, where the mechanism is embedded in the source device to enhance the ability of the system to automatically assign the identification number to each blood glucose measurement (mmol/L) during multiple patients monitoring. Additionally, the results from the experiments conducted showed that the developed system produced better overall performance compared to the Bluetooth BGM and conventional BGM system in terms of the shortest recording time and the ability to retransmit data. In the reliability analysis using ANOVA and DOE statistical methods, the result validates that the number of hop and number of end node significantly affects the PDR performance of conventional CSMA/CA. These two parameters are then taken into account in experimental setup for performance evaluation of the enhanced CSMA/CA (EN-CSMA/CA) algorithm that uses an external interrupt mechanism and a cross layer approach. The PDR increased from 94% (conventional CSMA/CA) to 99.33% (EN-CSMA/CA), an improvement of 5.33%. The PDR model estimates that for the best and worst scenario, the percentage of PDR is 100.0% and 51.67%, respectively. To optimize the arrangement of routers for real implementation of the developed system in health facilities, the developed path loss model estimates that the router should be positioned at a distance of 30 m from each other, which agrees with the test results which indicate that the router should be positioned ≤ 40 m in order to achieve the best PDR performance

    On the use of IEEE 802.15.4/Zigbee for time-sensitive wireless sensor network applications

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    Mestrado em Engenharia Electrotécnica e de ComputadoresRecent advancements in information and communication technologies are paving the way for new paradigms in embedded computing systems. This, allied with an increasing eagerness for monitoring and controlling everything, everywhere, is pushing forward the design of new Wireless Sensor Network (WSN) infrastructures that will tightly interact with the physical environment, in a ubiquitous and pervasive fashion. Such cyber-physical systems require a rethinking of the usual computing and networking concepts, and given that the computing entities closely interact with their environment, timeliness is of increasing importance. This Thesis addresses the use of standard protocols, particularly IEEE 802.15.4 and ZigBee, combined with commercial technologies as a baseline to enable WSN infrastructures capable of supporting the Quality of Service (QoS) requirements (specially timeliness and system lifetime) that future large-scale networked embedded systems will impose. With this purpose, in this Thesis we start by evaluating the network performance of the IEEE 802.15.4 Slotted CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) mechanism for different parameter settings, both through simulation and through an experimental testbed. In order to improve the performance of these networks (e.g. throughput, energyefficiency, message delay) against the hidden-terminal problem, a mechanism to mitigate it was implemented and experimentally validated. The effectiveness of this mechanism was also demonstrated in a real application scenario, featuring a target tracking application. A methodology for modelling cluster-tree WSNs and computing the worst-case endto-end delays, buffering and bandwidth requirements was tested and validated experimentally. This work is of paramount importance to understand the behaviour of WSNs under worst-case conditions and also to make the appropriate network settings. Our experimental work enabled us to identify a number of technological constrains, namely related to hardware/software and to the Open-ZB implementation in TinyOS. In this line, a new implementation effort was triggered to port the Open-ZB IEEE 802.15.4/ZigBee protocol stack to the ERIKA real-time operating system. This implementation was validated experimentally and its behaviour compared with the TinyOS–based implementation.Os últimos avanços nas tecnologias de informação e comunicação (ICTs) estão a abrir caminho para novos paradigmas de sistemas computacionais embebidos. Este facto, aliado à tendência crescente em monitorizar e controlar tudo, em qualquer lugar, está a alimentar o desenvolvimento de novas infra-estruturas de Redes de Sensores Sem Fios (WSNs), que irão interagir intimamente com o mundo físico de uma forma ubíqua. Este género de sistemas ciber-físicos de grande escala, requer uma reflexão sobre os conceitos de redes e de computação tradicionais, e tendo em conta a proximidade que estas entidades partilham com ambiente envolvente, o seu comportamento temporal é de acrescida importância. Esta Tese endereça a utilização de protocolos normalizados, em particular do IEEE 802.15.4 e ZigBee em conjunto com tecnologias comerciais, para desenvolver infraestruturas WSN capazes de responder aos requisitos de Qualidade de Serviço (QoS) (especialmente em termos de comportamento temporal e tempo de vida do sistema), que os futuros sistemas embebidos de grande escala deverão exigir. Com este propósito, nesta Tese começamos por analisar a performance do mecanismo de Slotted CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) do IEEE 802.15.4 para diferentes parâmetros, através de simulação e experimentalmente. De modo a melhorar a performance destas redes (ex. throughput, eficiência energética, atrasos) em cenários que contenham nós escondidos (hidden-nodes), foi implementado e validado experimentalmente um mecanismo para eliminar este problema. A eficácia deste mecanismo foi também demonstrada num cenário aplicacional real. Foi testada e validada uma metodologia para modelizar uma WSN em cluster-tree e calcular os piores atrasos das mensagens, necessidades de buffering e de largura de banda. Este trabalho foi de grande importância para compreender o comportamento deste tipo de redes para condições de utilização limite e para as configurar a priori. O nosso trabalho experimental permitiu identificar uma série de limitações tecnológicas, nomeadamente relacionadas com hardware/software e outras relacionadas com a implementação do Open-ZB em TinyOS. Isto desencadeou a migração da pilha protocolar IEEE 802.15.4/ZigBee Open-ZB para o ERIKA, um sistema operativo de tempo-real. Esta implementação foi validada experimentalmente e o seu comportamento comparado com o da implementação baseada em TinyOS

    Reliable Lifespan Evaluation of a Remote Environment Monitoring System Based on Wireless Sensor Networks and Global System for Mobile Communications

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    The use of wireless sensor networks (WSN) for monitoring physical and chemical variables in large areas allows density and frequency measurements which have been unavailable to date in classical measurement systems. To fully take advantage of this technology in a particular application, besides an accurate design and selection of all the components involved in its operation, it is essential to dispose of reliable lifetime estimation prior to deployment. This paper presents an experimental approach to determine the actual lifetime of such battery-operated systems, making use of a custom WSN architecture, and for different batteries technologies. To render a reliable evaluation, the energy consumption of the sensor nodes under their different operation modes, in correlation with the battery characteristics and the voltage regulation system, is jointly considered. The result is a complete and practical lifetime model, whose appropriate performance has been validated in a real deployment scenario

    A Hierarchical Architectural Framework for Securing Unmanned Aerial Systems

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    Unmanned Aerial Systems (UAS) are becoming more widely used in the new era of evolving technology; increasing performance while decreasing size, weight, and cost. A UAS equipped with a Flight Control System (FCS) that can be used to fly semi- or fully-autonomous is a prime example of a Cyber Physical and Safety Critical system. Current Cyber-Physical defenses against malicious attacks are structured around security standards for best practices involving the development of protocols and the digital software implementation. Thus far, few attempts have been made to embed security into the architecture of the system considering security as a holistic problem. Therefore, a Hierarchical, Embedded, Cyber Attack Detection (HECAD) framework is developed to provide security in a holistic manor, providing resiliency against cyber-attacks as well as introducing strategies for mitigating and dealing with component failures. Traversing the hardware/software barrier, HECAD provides detection of malicious faults at the hardware and software level; verified through the development of an FPGA implementation and tested using a UAS FCS

    Demystifying Internet of Things Security

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    Break down the misconceptions of the Internet of Things by examining the different security building blocks available in Intel Architecture (IA) based IoT platforms. This open access book reviews the threat pyramid, secure boot, chain of trust, and the SW stack leading up to defense-in-depth. The IoT presents unique challenges in implementing security and Intel has both CPU and Isolated Security Engine capabilities to simplify it. This book explores the challenges to secure these devices to make them immune to different threats originating from within and outside the network. The requirements and robustness rules to protect the assets vary greatly and there is no single blanket solution approach to implement security. Demystifying Internet of Things Security provides clarity to industry professionals and provides and overview of different security solutions What You'll Learn Secure devices, immunizing them against different threats originating from inside and outside the network Gather an overview of the different security building blocks available in Intel Architecture (IA) based IoT platforms Understand the threat pyramid, secure boot, chain of trust, and the software stack leading up to defense-in-depth Who This Book Is For Strategists, developers, architects, and managers in the embedded and Internet of Things (IoT) space trying to understand and implement the security in the IoT devices/platforms
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