Download or read book Secure Localization and Time Synchronization for Wireless Sensor and Ad Hoc Networks written by Radha Poovendran and published by Springer Science & Business Media. This book was released on 2007-12-03 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the latest research results in the area of secure localization for both wireless mobile ad hoc networks and wireless sensor networks. It is suitable as a text for computer science courses in wireless systems and security. It includes implementation studies with mica2 mote sensors. Due to the open spectrum nature of wireless communication, it is subject to attacks and intrusions. Hence the wireless network synchronization needs to be both robust and secure. Furthermore, issues such as energy constraints and mobility make the localization process even more challenging. The book will also interest developers of secure wireless systems.
Download or read book Synchronization and Localization in Wireless Networks written by Bernhard Etzlinger and published by Foundations and Trends in Signal Processing. This book was released on 2018-03-28 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern day networking and computing systems rely increasingly on knowing the location of the user. These include state-of-the art technologies such as navigation of vehicles and robots, traffic planning, or light control in smart home environments. In the future, even more services will appear. The predominant localization technology currently uses satellite signals but this only works outdoors, is expensive, and consumes considerable power. Alternative localization technologies have been recently developed using optical, ultra-sound, or radar techniques. All of these require additional hardware components to work effectively. Radio-frequency (RF) localization is a technique that uses communication signals to perform the task without the need for any extra hardware. This monograph addresses the role of synchronization in radio localization and provides a comprehensive overview of recent developments suitable for current and future practical implementations. The material is intended for both theoreticians and practitioners and is written to be accessible to novices while covering state-of-the-art topics of interest to advanced researchers of localization and synchronization systems.
Download or read book Secure Localization and Time Synchronization for Wireless Sensor and Ad Hoc Networks written by Radha Poovendran and published by Springer. This book was released on 2006-11-14 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the latest research results in the area of secure localization for both wireless mobile ad hoc networks and wireless sensor networks. It is suitable as a text for computer science courses in wireless systems and security. It includes implementation studies with mica2 mote sensors. Due to the open spectrum nature of wireless communication, it is subject to attacks and intrusions. Hence the wireless network synchronization needs to be both robust and secure. Furthermore, issues such as energy constraints and mobility make the localization process even more challenging. The book will also interest developers of secure wireless systems.
Download or read book Time Synchronization and Localization in Wireless Networks written by Khalid Almuzaini and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Localization is very important for self-organizing wireless networks. The localization process involves two main steps: ranging, i.e., estimating the distance between an unlocalized node and the anchor nodes within its range, and the localization algorithm to compute the location of the unlocalized nodes using the anchor coordinates and the estimated ranges. To be able to estimate the distance, the receiver needs to detect the arrival time of the received signals precisely. Thus, the first part of this research is related to time synchronization. We propose two new symbol timing offset estimation (STO) algorithms that can detect the start of an orthogonal frequency division multiplexing (OFDM) symbol more accurately than others in a Rayleigh fading channel. OFDM is used to perform timing synchronization because it is incorporated in many current and future wireless systems such as 802.11, WiMAX, wireless USB, and WiMedia. The first proposed algorithm uses a metric that is calculated recursively. Two estimation methods are considered: one using the average of the metric results, and the other using the median. The second approach uses a preamble designed to have a maximum timing metric for the correct location and very small values otherwise. These algorithms are shown to outperform recent algorithms in the literature. In the second part of this dissertation we explore the second step of the localization problem. There are two kinds of localization: range-free and range-based. A new distributed range-free localization algorithm is proposed where every unlocalized node forms two sets of anchors. The first set contains one-hop anchors from the unlocalized node. The second set contains two-hop and three-hop anchors away from the unlocalized node. Each unlocalized node uses the intersections between the ranging radii of these anchors to estimate its position. Four different range-based localization algorithms are proposed. These algorithms use techniques from data mining to process the intersection points between an unlocalized node and nearby anchors. The first proposed scheme is based on decision tree classification to select a group of intersection points. The second is based on the decision tree classification and K-means clustering algorithms applied to the selected intersection points by the decision trees. The third is based on decision tree classification and the density-based spatial clustering of applications with noise (DBSCAN) algorithm applied to the intersection points selected by decision trees. The last approach uses the density-based outlier detection (DBOD) algorithm. DBOD assigns density values to each point being used in the location estimation. The mean of these densities is calculated and those points having a density larger than the mean are kept as candidate points. These proposed approaches are shown to outperform recent algorithms in the literature.
Download or read book Unified Approach to Time Synchronization and Localization in Wireless Sensor Networks written by Jun Zheng (electronic engineer.) and published by . This book was released on 2009 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Localization in Wireless Networks written by Jessica Feng Sanford and published by Springer Science & Business Media. This book was released on 2012-05-03 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a computational tour-de-force, this volume wipes away a host of problems related to location discovery in wireless ad-hoc sensor networks. WASNs have recognized potential in many applications that are location-dependent, yet are heavily constrained by factors such as cost and energy consumption. Their “ad-hoc” nature, with direct rather than mediated connections between a network of wireless devices, adds another layer of difficulty. Basing this work entirely on data-driven, coordinated algorithms, the author’s aim is to present location discovery techniques that are highly accurate—and which fit user criteria. The research deploys nonparametric statistical methods and relies on the concept of joint probability to construct error (including location error) models and environmental field models. It also addresses system issues such as the broadcast and scheduling of the beacon. Reporting an impressive accuracy gain of almost 17 percent, and organized in a clear, sequential manner, this book represents a stride forward in wireless localization.
Download or read book Clock Synchronization and Localization for Wireless Sensor Network written by Cheng-Yu Han and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless sensor networks (WSNs) play an important role in applications such as environmental monitoring, source tracking, and health care,... In WSN, sensors have the ability to perform data sampling, distributed computing and information fusion. To perform such complex tasks, clock synchronization and localization are two fundamental and essential algorithms. WSNs have been widely studied in the past years, and the scientific literature reports many outcomes that make them applicable for some applications. For some others, research still needs to find solutions to some of the challenges posed by battery limitation, dynamicity, and low computing clock rate. With the aim of contributing to the research on WSN, this thesis proposes new algorithms for both clock synchronization and localization. For clock synchronization, sensors converge their local physical clock to perform data fusion. By applying the clock synchronization algorithm, sensors converge the time difference and therefore work at the same rate. In view of dynamicity, low computing and sparsity of WSN, a new pulse-coupled decentralized synchronization algorithm is proposed to improve the precision of the synchronization. The benefit of this kind of algorithm is that sensors only exchange zero-bit pulse instead of packets, so not only the communication is efficient but also robust to any failure of the sensors in the network. Localization of sensors has been widely studied. However, the quality and the accuracy of the localization still have a large room to improve. This thesis apply Leave-out Sign-dominant Correlated Regions (LSCR) algorithm to localization problem. With LSCR, one evaluates the accurate estimates of confidence regions with prescribed confidence levels, which provide not only the location but also the confidence of the estimation. In this thesis, several localization approaches are implemented and compared. The simulation result shows under mild assumptions, LSCR obtains competitive results compared to other methods.
Download or read book Localization and Time Synchronization in Wireless Sensor Networks written by Ge Huang and published by . This book was released on 2012 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Location Localization and Localizability written by Yunhao Liu and published by Springer Science & Business Media. This book was released on 2010-11-01 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reflects up-to-date research, fundamental theories, and key techniques of of wireless localization technology and error-controlling techniques. It also presents and discusses the issue of localizability, as well as privacy issues associated with LBS. This book encompasses the significant and quickly growing area of wireless localization technology. It presents comprehensive and up-to-date research in both fundamental theories and key techniques of network localization. In addition to localization approaches, it also is the first book to address the issue of localizability. The privacy issue of LBS technology is also discussed.
Download or read book Principles of Wireless Access and Localization written by Kaveh Pahlavan and published by John Wiley & Sons. This book was released on 2013-09-03 with total page 766 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive, encompassing and accessible text examining a wide range of key Wireless Networking and Localization technologies This book provides a unified treatment of issues related to all wireless access and wireless localization techniques. The book reflects principles of design and deployment of infrastructure for wireless access and localization for wide, local, and personal networking. Description of wireless access methods includes design and deployment of traditional TDMA and CDMA technologies and emerging Long Term Evolution (LTE) techniques for wide area cellular networks, the IEEE 802.11/WiFi wireless local area networks as well as IEEE 802.15 Bluetooth, ZigBee, Ultra Wideband (UWB), RF Microwave and body area networks used for sensor and ad hoc networks. The principles of wireless localization techniques using time-of-arrival and received-signal-strength of the wireless signal used in military and commercial applications in smart devices operating in urban, indoor and inside the human body localization are explained and compared. Questions, problem sets and hands-on projects enhances the learning experience for students to understand and appreciate the subject. These include analytical and practical examples with software projects to challenge students in practically important simulation problems, and problem sets that use MatLab. Key features: Provides a broad coverage of main wireless technologies including emerging technical developments such as body area networking and cyber physical systems Written in a tutorial form that can be used by students and researchers in the field Includes practical examples and software projects to challenge students in practically important simulation problems
Download or read book Localization Algorithms and Strategies for Wireless Sensor Networks Monitoring and Surveillance Techniques for Target Tracking written by Mao, Guoqiang and published by IGI Global. This book was released on 2009-05-31 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless localization techniques are an area that has attracted interest from both industry and academia, with self-localization capability providing a highly desirable characteristic of wireless sensor networks. Localization Algorithms and Strategies for Wireless Sensor Networks encompasses the significant and fast growing area of wireless localization techniques. This book provides comprehensive and up-to-date coverage of topics and fundamental theories underpinning measurement techniques and localization algorithms. A useful compilation for academicians, researchers, and practitioners, this Premier Reference Source contains relevant references and the latest studies emerging out of the wireless sensor network field.
Download or read book Cooperative Wireless Networks for Localization written by Stefano Severi and published by LAP Lambert Academic Publishing. This book was released on 2010-09 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses the problem of localization for cooperative WSNs. Time synchronization is a fundamental requirement for every network. In this context, a new approach based on the estimation theory is proposed to evaluate the ultimate performance limit in network time synchronization. Sensor network localization algorithms estimate the locations of sensors with initially unknown location information by using knowledge of the absolute positions of a few sensors and inter-sensor measurements such as distance and bearing measurements. A new Semidefinite Programming (SDP) framework to analyze and solve the problem of flip- ambiguity that afflicts range-based network localization algorithms with incomplete ranging information. Another contribution in the field of position estimate is about multihop networks, network with a low degree of connectivity, in which couples of given any nodes, in order to communicate, have to rely on one or more intermediate nodes (hops). The last point of this book discuss a new low-complexity tracking algorithm for the position tracking of a user in a WLAN-based indoor localization system.
Download or read book Time Synchronization and Localization in Sensor Networks written by Kay Römer and published by . This book was released on 2005 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Timing Synchronization and Node Localization in Wireless Sensor Networks written by Aitzaz Ahmad and published by . This book was released on 2013 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless sensor networks (WSNs) consist of a large number of sensor nodes, capable of on-board sensing and data processing, that are employed to observe some phenomenon of interest. With their desirable properties of flexible deployment, resistance to harsh environment and lower implementation cost, WSNs envisage a plethora of applications in diverse areas such as industrial process control, battle- field surveillance, health monitoring, and target localization and tracking. Much of the sensing and communication paradigm in WSNs involves ensuring power efficient transmission and finding scalable algorithms that can deliver the desired performance objectives while minimizing overall energy utilization. Since power is primarily consumed in radio transmissions delivering timing information, clock synchronization represents an indispensable requirement to boost network lifetime. This dissertation focuses on deriving efficient estimators and performance bounds for the clock parameters in a classical frequentist inference approach as well as in a Bayesian estimation framework. A unified approach to the maximum likelihood (ML) estimation of clock offset is presented for different network delay distributions. This constitutes an analytical alternative to prior works which rely on a graphical maximization of the likelihood function. In order to capture the imperfections in node oscillators, which may render a time-varying nature to the clock offset, a novel Bayesian approach to the clock offset estimation is proposed by using factor graphs. Message passing using the max-product algorithm yields an exact expression for the Bayesian inference problem. This extends the current literature to cases where the clock offset is not deterministic, but is in fact a random process. A natural extension of pairwise synchronization is to develop algorithms for the more challenging case of network-wide synchronization. Assuming exponentially distributed random delays, a network-wide clock synchronization algorithm is proposed using a factor graph representation of the network. Message passing using the max- product algorithm is adopted to derive the update rules for the proposed iterative procedure. A closed form solution is obtained for each node's belief about its clock offset at each iteration. Identifying the close connections between the problems of node localization and clock synchronization, we also address in this dissertation the problem of joint estimation of an unknown node's location and clock parameters by incorporating the effect of imperfections in node oscillators. In order to alleviate the computational complexity associated with the optimal maximum a-posteriori estimator, two iterative approaches are proposed as simpler alternatives. The first approach utilizes an Expectation-Maximization (EM) based algorithm which iteratively estimates the clock parameters and the location of the unknown node. The EM algorithm is further simplified by a non-linear processing of the data to obtain a closed form solution of the location estimation problem using the least squares (LS) approach. The performance of the estimation algorithms is benchmarked by deriving the Hybrid Cramer-Rao lower bound (HCRB) on the mean square error (MSE) of the estimators. We also derive theoretical lower bounds on the MSE of an estimator in a classical frequentist inference approach as well as in a Bayesian estimation framework when the likelihood function is an arbitrary member of the exponential family. The lower bounds not only serve to compare various estimators in our work, but can also be useful in their own right in parameter estimation theory. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/148131
Download or read book Synchronous data acquisition with wireless sensor networks written by Funck, Jürgen Helmut and published by Universitätsverlag der TU Berlin. This book was released on 2018-07-19 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless sensor networks (WSN) are predicted to play a key role in future technological developments like the internet of things. Already they are beginning to be used in many applications not only in the scientific and industrial domains. One of the biggest challenges, when using WSN, is to fuse and evaluate data from different sensor nodes. Synchronizing the data acquisition of the nodes is a key enabling factor for this. So far research has been focused on synchronizing the clocks of the nodes, largely neglecting the implications for the actual measurement results. This thesis investigates the relation between synchronization accuracy and quality of measurement results. Two different classes of time synchronous data acquisition are investigated: event detection and waveform sampling. A model is developed that describes a WSN as a generic multi-channel data acquisition system, thus enabling direct comparison to other existing systems. With the help of this model it is shown, that synchronization accuracy should best be expressed as uncertainty of the acquired timing information. This way, not only the contribution of the synchronization to the overall measurement uncertainty can be assessed, but also the synchronization accuracy required for an application can be estimated. The insights from the uncertainty analysis are used to develop two distinct approaches to synchronous data acquisition: a proactive and a reactive one. It is shown that the reactive approach can also be used to efficiently implement synchronous angular sampling, i.e. data acquisition synchronous to the rotation of a machine's shaft. Furthermore, testing methods are suggested, that evaluate the synchronized data acquisition of an existing WSN as a whole. These methods can be applied to other data acquisition systems without changes, thus enabling direct comparisons. The practical realization of a WSN is described, on which the developed data acquisition methods have been implemented. All implementations were thoroughly tested in experiments, using the suggested testing methods. This way it was revealed, that a system's interrupt handling procedures may have a strong influence on the data acquisition. Furthermore, it was shown that the effective use of fixed-point arithmetic enables synchronous angular sampling in real-time during a streaming measurement. Finally, two application examples are used to illustrate the utility of the implemented data acquisition: the acoustic localization of two sensor nodes on a straight line and a simple order tracking at an induction motor test bench. Diese Dissertation untersucht die Zusammenhänge zwischen Synchronisationsgenauigkeit und Qualität der Messergebnisse. Zwei Klassen von zeitsynchroner Datenerfassung werden dabei betrachtet: die Detektion von Ereignissen und die Aufnahme von Kurvenformen. Es wird ein Modell entwickelt, welches ein WSN als ein allgemeines mehrkanaliges Datenerfassungssystem beschreibt. Dies ermöglicht den direkten Vergleich zwischen WSN und anderen Messsystemen. Weiter wird mit Hilfe des Modells gezeigt, dass die Synchronisationsgenauigkeit vorzugsweise als Unsicherheit der Zeitinformation angegeben werden sollte. Hierdurch kann nicht nur der Beitrag der Synchronisation zur gesamten Messunsicherheit bestimmt sondern auch die von einer Anwendung tatsächlich benötigte Synchronisationsgenauigkeit abgeschätzt werden. Ausgehend von den durch die Unsicherheitsbetrachtung gewonnenen Erkenntnissen werden ein proaktiver und ein reaktiver Ansatz zur synchronen Datenaufnahme entwickelt. Mit dem reaktiven Ansatz können Messdaten auch effizient drehwinkelsynchron, d. h. synchron zur Drehbewegung einer Maschinenwelle, aufgenommen werden. Es werden Testverfahren vorgeschlagen, mit denen sich die Synchronizität der Datenerfassung für ein WSN als Ganzes überprüfen lässt. Diese Verfahren lassen sich unverändert auf andere Messsysteme anwenden und ermöglichen somit direkte Vergleiche. Es wird die praktische Umsetzung eines WSN beschrieben, auf dem die entwickelten Methoden zur Datenerfassung implementiert wurden. Alle Implementierungen wurden mit den vorgeschlagenen Testverfahren untersucht. Hierdurch konnte gezeigt werden, dass die Interrupt-Bearbeitung der Sensorknoten entscheidenden Einfluss auf die Messdatenerfassung hat. Weiter konnte durch den Einsatz von Fixed-Punkt-Arithmetik die drehwinkelsynchrone Datenerfassung in Echtzeit realisiert werden. Schließlich wird die Nützlichkeit der implementierten Datenerfassung an zwei Anwendungen gezeigt: der akustischen Ortung zweier Sensorknoten sowie einer einfachen Ordnungsanalyse.
Download or read book Networking Wireless Sensors written by Bhaskar Krishnamachari and published by Cambridge University Press. This book was released on 2005-12-22 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless sensor networks promise an unprecedented fine-grained interface between the virtual and physical worlds. They are one of the most rapidly developing information technologies, with applications in a wide range of fields including industrial process control, security and surveillance, environmental sensing, and structural health monitoring. Originally published in 2005, this book provides a detailed and organized survey of the field. It shows how the core challenges of energy efficiency, robustness, and autonomy are addressed in these systems by networking techniques across multiple layers. The topics covered include network deployment, localization, time synchronization, wireless radio characteristics, medium-access, topology control, routing, data-centric techniques, and transport protocols. Ideal for researchers and designers seeking to create algorithms and protocols and engineers implementing integrated solutions, it also contains many exercises and can be used by graduate students taking courses in networks.
Download or read book Fundamentals of Wireless Sensor Networks written by Waltenegus Dargie and published by John Wiley & Sons. This book was released on 2010-11-05 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, the authors describe the fundamental concepts and practical aspects of wireless sensor networks. The book provides a comprehensive view to this rapidly evolving field, including its many novel applications, ranging from protecting civil infrastructure to pervasive health monitoring. Using detailed examples and illustrations, this book provides an inside track on the current state of the technology. The book is divided into three parts. In Part I, several node architectures, applications and operating systems are discussed. In Part II, the basic architectural frameworks, including the key building blocks required for constructing large-scale, energy-efficient sensor networks are presented. In Part III, the challenges and approaches pertaining to local and global management strategies are presented – this includes topics on power management, sensor node localization, time synchronization, and security. At the end of each chapter, the authors provide practical exercises to help students strengthen their grip on the subject. There are more than 200 exercises altogether. Key Features: Offers a comprehensive introduction to the theoretical and practical concepts pertaining to wireless sensor networks Explains the constraints and challenges of wireless sensor network design; and discusses the most promising solutions Provides an in-depth treatment of the most critical technologies for sensor network communications, power management, security, and programming Reviews the latest research results in sensor network design, and demonstrates how the individual components fit together to build complex sensing systems for a variety of application scenarios Includes an accompanying website containing solutions to exercises (http://www.wiley.com/go/dargie_fundamentals) This book serves as an introductory text to the field of wireless sensor networks at both graduate and advanced undergraduate level, but it will also appeal to researchers and practitioners wishing to learn about sensor network technologies and their application areas, including environmental monitoring, protection of civil infrastructure, health care, precision agriculture, traffic control, and homeland security.