199 research outputs found

    A Study On Energy Efficient Multi-Tier Multi-Hop Wireless Sensor Networks For Freight-Train Monitoring

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    The North American freight railroad industry is trying to leverage wireless sensor networks (WSN) onboard railcars for advanced monitoring and alerting. In railroad environments, freight train WSNs exhibit a linear chain-like topology of significant length. Thus, existing wireless technologies such as the IEEE 802.15.4 communication protocol, based on a star topology, are unable to provide reliable service. The end-to-end communication between nodes generally relies on individual nodes communicating with their respective neighbors to carry the information over multiple hops and deliver it to the preferred destination. The routing performance and reliability significantly degrades with increasing number of hops. We proposed a multitier multi-hop network which is designed to overcome these issues in large-scale multi-hop WSNs in railroad environments. This approach has significant advantages, such as more data bandwidth, higher reliability, and lower energy consumption. Our analytical results show that the proposed multi-tier communication approach spends energy more efficiently and utilizes less resource than the traditional chain topology on board freight trains

    Study of RF Propagation Characteristics for Wireless Sensor Networks in Railroad Environments

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    The freight railroad industry in North America is exerting efforts to leverage Wireless Sensor Networks to monitor systems and components on railcars. This allows fault detection and accident prevention even while a train is moving. Railcars, constructed mostly of ferrous materials such as steel, are expected to severely impact signal propagation. To better understand this effect we first evaluated the signal characteristics when sensor nodes are placed in various locations around railcars. We used EM-Field modeling and evaluation techniques to obtain these results and found that node placement selection is critical for the node’s communication distance. As a second research area we therefore aimed at understanding the protocol requirements and limitations of current WSN technologies. Based on the results of our study we found ZigBee to be inadequate for freight WSNs and developed a solution that remedies the problems we observed. Our evaluation of this new multi-tier approach shows a significant performance and network lifetime gain, making freight train wireless sensor networks feasible

    Asynchronous Resilient Wireless Sensor Network for Train Integrity Monitoring

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    To increase railway use efficiency, the European Railway Traffic Management System (ERTMS) Level 3 requires all trains to constantly and reliably self-monitor and report their integrity and track position without infrastructure support. Timely train separation detection is challenging, especially for long freight trains without electrical power on cars. Data fusion of multiple monitoring techniques is currently investigated, including distributed integrity sensing of all train couplings. We propose a Wireless Sensor Network (WSN) topology, communication protocol, application, and sensor nodes prototypes designed for low power timely train integrity reporting in unreliable conditions, like intermittent node operation and network association (e.g., in low environmental energy harvesting conditions) and unreliable radio links. Each train coupling is redundantly monitored by four sensors, which can help to satisfy the Train Collision Avoidance System (TCAS) and European Committee for Electrotechnical Standardization (CENELEC) SIL 4 requirements and contribute to the reliability of the asynchronous network with low rejoin overhead. A control center on the locomotive controls the WSN and receives the reports, helping the integration in railway or Internet of Things (IoT) applications. Software simulations of the embedded application code virtually unchanged show that the energy-optimized configurations check a 50-car train integrity (about 1 km long) in 3.6 s average with 0.1 s standard deviation and that more than 95 % of the reports are delivered successfully with up to one-third of communications or up to 15 % of the nodes failed. We also report qualitative test results for a 20-node network in different experimental conditions

    Study of an onboard wired-wireless health monitoring system equipped with power save algorithm for freight railway wagons

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    Goods transport is an essential factor for the European market for its significant contribution to economic growth and thus to the creation of new employment. Nowadays, approximately 75% of goods are transported by road within the European Union. The use of more efficient and sustainable modes of transportation, such as rail transport and inland waterways, would reduce oil imports and pollution abatement. The growth of rail goods transport must be accompanied by an increasing introduction of tools and technologies that make possible to constantly monitor the European rolling stock. The introduction of monitoring technologies that allow to constantly know the status of the wagon would bring real and concrete benefits to the world of rail transport enabling to optimize the maintenance of rolling stock thus reducing costs but ensuring at the same time a maximization of the safety. Currently, the only information available are provided by the equipment installed along the railway network, separated by tens of kilometers. However, to identify and intervene on an incipient failure, it is necessary to have continuous monitoring and a communication system that can warn the train conductor and the maintenance staff of wagon’s owners. A good monitoring system has to be: cheap, energy autonomous, wireless and reliable. Currently monitoring systems can be divided into two large groups. The former are those developed by universities or research centres within projects financed by third parties, while the latter are monitoring systems developed individually by companies operating in the logistics sector. In light of the existing research projects and products already available on the market, the following thesis work aims to develop a monitoring system demonstrator dedicated to freight wagons that can demonstrate the effectiveness of these devices. The results of preliminary literature and market analyses served as the base for the realization of a first wired demonstrator. All the subsystems of the first demonstrator were long tested in laboratory in order to guarantee the maximum reliability of the device and maximum repeatability of the recorded data. The parameters monitored were the pressures of the pneumatic braking system, the temperature of the cast-iron brake blocks and the dynamics of the body frame. The second demonstrator developed was significantly more complex. In fact, it consists of two wireless units: a base station which represents the further development of the first demonstrator and a completely new axle box node monitoring system. From the analysis of the brake block temperature data two fundamental aspects emerge. The first is the need and importance of maintaining the braking system always in good conditions, doing maintenance in line with the regulations. The second is related to the adoption of new brake blocks in synthetic material. In fact, in addition to the complete review of the brake system as prescribed by the regulation, also the material of the wheelsets must be suitable for the use of new type of brake blocks. Another aspect subject to monitoring in this work is the vibration monitoring. Vibrations of particular interest for freight wagon monitoring are those along the vertical axis and the longitudinal axis. The accelerations along the vertical axis in fact describe the stability of the vehicle and its interaction with the rails. Vertical acceleration is a parameter that allows to determine if the wagon is traveling safely or not. In fact, this parameter makes it possible to identify a possible derailment, if the acceleration level recorded is anomalous. The longitudinal acceleration is a parameter monitored by all the railway monitoring devices present on the market. It is important to know the longitudinal accelerometric levels both in the phases of train composition and during the braking operations in order to identify possible incorrect behaviour. The second demonstrator allowed to monitor the external temperature of the axle box cover and verified the correct behaviour of bearings. The most important result of the second demonstrator was the creation of a wireless network that makes it possible to monitor any quantities without invasive wiring. The creation of a wireless network has also required the development of power saving algorithms for the reduction of energy consumption in order to obtain the maximum operating time. In both prototypes developed, the monitored parameters were very numerous and were sampled with a very high frequency, especially those related to temperatures and pressures. This is a typical feature of the demonstrators. Instead, in order to monitor and study the phenomena related to the dynamics of the wagon it is necessary a sampling frequency as the one adopted. The developed prototypes, even if marked by a strong manual activity, have shown a very high reliability. Monitoring all these parameters for such a long distance led to the creation of a large database. Generally, only large industrial groups can boast such prolonged tests. The prototypes made, thanks to their hardware and software effectiveness, were the basis for the most complex monitoring system that we have set ourselves to achieve with the SWAM Rail project. In conclusion, the project carried out in these three years has therefore obtained as results the realization of demonstrators of monitoring devices, the collection of data that would allow to understand and study the operation of a wagon in optimal maintenance conditions, the development of thermal models and the identification of threshold parameters for delimiting conditions of normal operation by fault conditions

    Energy Efficiency

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    This book is one of the most comprehensive and up-to-date books written on Energy Efficiency. The readers will learn about different technologies for energy efficiency policies and programs to reduce the amount of energy. The book provides some studies and specific sets of policies and programs that are implemented in order to maximize the potential for energy efficiency improvement. It contains unique insights from scientists with academic and industrial expertise in the field of energy efficiency collected in this multi-disciplinary forum

    A wireless sensor network system for border security and crossing detection

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    The protection of long stretches of countries’ borders has posed a number of challenges. Effective and continuous monitoring of a border requires the implementation of multi-surveillance technologies, such as Wireless Sensor Networks (WSN), that work as an integrated unit to meet the desired goals. The research presented in this thesis investigates the application of topologically Linear WSN (LWSNs) to international border monitoring and surveillance. The main research questions studied here are: What is the best form of node deployment and hierarchy? What is the minimum number of sensor nodes to achieve k− barrier coverage in a given belt region? iven an appropriate network density, how do we determine if a region is indeed k−barrier covered? What are the factors that affect barrier coverage? How to organise nodes into logical segments to perform in-network processing of data? How to transfer information from the networks to the end users while maintaining critical QoS measures such as timeliness and accuracy. To address these questions, we propose an architecture that specifies a mechanism to assign nodes to various network levels depending on their location. These levels are used by a cross-layer communication protocol to achieve data delivery at the lowest possible cost and minimal delivery delay. Building on this levelled architecture, we study the formation of weak and strong barriers and how they determine border crossing detection probability. We propose new method to calculate the required node density to provide higher intruder detection rate. Then, we study the effect of people movement models on the border crossing detection probability. At the data link layer, new energy balancing along with shifted MAC protocol are introduced to further increase the network lifetime and delivery speed. In addition, at network layer, a routing protocol called Level Division raph (LD ) is developed. LD utilises a complex link cost measurement to insure best QoS data delivery to the sink node at the lowest possible cost. The proposed system has the ability to work independently or cooperatively with other monitoring technologies, such as drowns and mobile monitoring stations. The performance of the proposed work is extensively evaluated analytically and in simulation using real-life conditions and parameters. The simulation results show significant performance gains when comparing LD to its best rivals in the literature Dynamic Source Routing. Compared to DSR, LD achieves higher performance in terms of average end-to-end delays by up to 95%, packet delivery ratio by up to 20%, and throughput by up to 60%, while maintaining similar performance in terms of normalised routing load and energy consumption

    The intelligent container concept : issues, initiatives, and implementation

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    Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2007.Includes bibliographical references (p. 104-111).Shipping containers have been under increased scrutiny in recent years for two primary reasons. Within the private sector, they are one component of a continuing process by organizations to use effective supply chain management to their competitive advantage. Within the public sector, they are the central focus of a growing concern over cargo security. Indeed, these issues involve many parties, including regulators, carriers, shippers, container solution providers, research, and academia. Many of the proposed solutions involve new strategies, systems, and technologies applied to containers that fall into what this paper calls the "intelligent container concept." As a relatively nascent field, information is currently very fragmented, standards are still being researched, and few universal goals exist. This study is focused on compiling, understanding, and organizing the universe of options available, the concerns of the parties involved, the relevant and significant initiatives underway or completed, and the issues surrounding implementation.(cont.) While cost and technology are critical components of the debate, this study focuses more on the benefits that the proposed solutions might add and how they can be incorporated into the supply chain. This study is intended to familiarize the reader with the status and extent of the intelligent container field, though does not delve into the cost or technology issues since they vary greatly and are supply chain specific.by Peter Christopher Bryn.S.M

    Enabling technologies and cyber-physical systems for mission-critical scenarios

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    Programa Oficial de Doutoramento en Tecnoloxías da Información e Comunicacións en Redes Móbiles . 5029P01[Abstract] Reliable transport systems, defense, public safety and quality assurance in the Industry 4.0 are essential in a modern society. In a mission-critical scenario, a mission failure would jeopardize human lives and put at risk some other assets whose impairment or loss would significantly harm society or business results. Even small degradations of the communications supporting the mission could have large and possibly dire consequences. On the one hand, mission-critical organizations wish to utilize the most modern, disruptive and innovative communication systems and technologies, and yet, on the other hand, need to comply with strict requirements, which are very different to those of non critical scenarios. The aim of this thesis is to assess the feasibility of applying emerging technologies like Internet of Things (IoT), Cyber-Physical Systems (CPS) and 4G broadband communications in mission-critical scenarios along three key critical infrastructure sectors: transportation, defense and public safety, and shipbuilding. Regarding the transport sector, this thesis provides an understanding of the progress of communications technologies used for railways since the implantation of Global System for Mobile communications-Railways (GSM-R). The aim of this work is to envision the potential contribution of Long Term Evolution (LTE) to provide additional features that GSM-R would never support. Furthermore, the ability of Industrial IoT for revolutionizing the railway industry and confront today's challenges is presented. Moreover, a detailed review of the most common flaws found in Radio Frequency IDentification (RFID) based IoT systems is presented, including the latest attacks described in the literature. As a result, a novel methodology for auditing security and reverse engineering RFID communications in transport applications is introduced. The second sector selected is driven by new operational needs and the challenges that arise from modern military deployments. The strategic advantages of 4G broadband technologies massively deployed in civil scenarios are examined. Furthermore, this thesis analyzes the great potential for applying IoT technologies to revolutionize modern warfare and provide benefits similar to those in industry. It identifies scenarios where defense and public safety could leverage better commercial IoT capabilities to deliver greater survivability to the warfighter or first responders, while reducing costs and increasing operation efficiency and effectiveness. The last part is devoted to the shipbuilding industry. After defining the novel concept of Shipyard 4.0, how a shipyard pipe workshop works and what are the requirements for building a smart pipe system are described in detail. Furthermore, the foundations for enabling an affordable CPS for Shipyards 4.0 are presented. The CPS proposed consists of a network of beacons that continuously collect information about the location of the pipes. Its design allows shipyards to obtain more information on the pipes and to make better use of it. Moreover, it is indicated how to build a positioning system from scratch in an environment as harsh in terms of communications as a shipyard, showing an example of its architecture and implementation.[Resumen] En la sociedad moderna, los sistemas de transporte fiables, la defensa, la seguridad pública y el control de la calidad en la Industria 4.0 son esenciales. En un escenario de misión crítica, el fracaso de una misión pone en peligro vidas humanas y en riesgo otros activos cuyo deterioro o pérdida perjudicaría significativamente a la sociedad o a los resultados de una empresa. Incluso pequeñas degradaciones en las comunicaciones que apoyan la misión podrían tener importantes y posiblemente terribles consecuencias. Por un lado, las organizaciones de misión crítica desean utilizar los sistemas y tecnologías de comunicación más modernos, disruptivos e innovadores y, sin embargo, deben cumplir requisitos estrictos que son muy diferentes a los relativos a escenarios no críticos. El objetivo principal de esta tesis es evaluar la viabilidad de aplicar tecnologías emergentes como Internet of Things (IoT), Cyber-Physical Systems (CPS) y comunicaciones de banda ancha 4G en escenarios de misión crítica en tres sectores clave de infraestructura crítica: transporte, defensa y seguridad pública, y construcción naval. Respecto al sector del transporte, esta tesis permite comprender el progreso de las tecnologías de comunicación en el ámbito ferroviario desde la implantación de Global System for Mobile communications-Railway (GSM-R). El objetivo de este trabajo es analizar la contribución potencial de Long Term Evolution (LTE) para proporcionar características adicionales que GSM-R nunca podría soportar. Además, se presenta la capacidad de la IoT industrial para revolucionar la industria ferroviaria y afrontar los retos actuales. Asimismo, se estudian con detalle las vulnerabilidades más comunes de los sistemas IoT basados en Radio Frequency IDentification (RFID), incluyendo los últimos ataques descritos en la literatura. Como resultado, se presenta una metodología innovadora para realizar auditorías de seguridad e ingeniería inversa de las comunicaciones RFID en aplicaciones de transporte. El segundo sector elegido viene impulsado por las nuevas necesidades operacionales y los desafíos que surgen de los despliegues militares modernos. Para afrontarlos, se analizan las ventajas estratégicas de las tecnologías de banda ancha 4G masivamente desplegadas en escenarios civiles. Asimismo, esta tesis analiza el gran potencial de aplicación de las tecnologías IoT para revolucionar la guerra moderna y proporcionar beneficios similares a los alcanzados por la industria. Se identifican escenarios en los que la defensa y la seguridad pública podrían aprovechar mejor las capacidades comerciales de IoT para ofrecer una mayor capacidad de supervivencia al combatiente o a los servicios de emergencias, a la vez que reduce los costes y aumenta la eficiencia y efectividad de las operaciones. La última parte se dedica a la industria de construcción naval. Después de definir el novedoso concepto de Astillero 4.0, se describe en detalle cómo funciona el taller de tubería de astillero y cuáles son los requisitos para construir un sistema de tuberías inteligentes. Además, se presentan los fundamentos para posibilitar un CPS asequible para Astilleros 4.0. El CPS propuesto consiste en una red de balizas que continuamente recogen información sobre la ubicación de las tuberías. Su diseño permite a los astilleros obtener más información sobre las tuberías y hacer un mejor uso de las mismas. Asimismo, se indica cómo construir un sistema de posicionamiento desde cero en un entorno tan hostil en términos de comunicaciones, mostrando un ejemplo de su arquitectura e implementación

    User mobility prediction and management using machine learning

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    The next generation mobile networks (NGMNs) are envisioned to overcome current user mobility limitations while improving the network performance. Some of the limitations envisioned for mobility management in the future mobile networks are: addressing the massive traffic growth bottlenecks; providing better quality and experience to end users; supporting ultra high data rates; ensuring ultra low latency, seamless handover (HOs) from one base station (BS) to another, etc. Thus, in order for future networks to manage users mobility through all of the stringent limitations mentioned, artificial intelligence (AI) is deemed to play a key role automating end-to-end process through machine learning (ML). The objectives of this thesis are to explore user mobility predictions and management use-cases using ML. First, background and literature review is presented which covers, current mobile networks overview, and ML-driven applications to enable user’s mobility and management. Followed by the use-cases of mobility prediction in dense mobile networks are analysed and optimised with the use of ML algorithms. The overall framework test accuracy of 91.17% was obtained in comparison to all other mobility prediction algorithms through artificial neural network (ANN). Furthermore, a concept of mobility prediction-based energy consumption is discussed to automate and classify user’s mobility and reduce carbon emissions under smart city transportation achieving 98.82% with k-nearest neighbour (KNN) classifier as an optimal result along with 31.83% energy savings gain. Finally, context-aware handover (HO) skipping scenario is analysed in order to improve over all quality of service (QoS) as a framework of mobility management in next generation networks (NGNs). The framework relies on passenger mobility, trains trajectory, travelling time and frequency, network load and signal ratio data in cardinal directions i.e, North, East, West, and South (NEWS) achieving optimum result of 94.51% through support vector machine (SVM) classifier. These results were fed into HO skipping techniques to analyse, coverage probability, throughput, and HO cost. This work is extended by blockchain-enabled privacy preservation mechanism to provide end-to-end secure platform throughout train passengers mobility
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