20 research outputs found

    New Approach of Indoor and Outdoor Localization Systems

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    Accurate determination of the mobile position constitutes the basis of many new applications. This book provides a detailed account of wireless systems for positioning, signal processing, radio localization techniques (Time Difference Of Arrival), performances evaluation, and localization applications. The first section is dedicated to Satellite systems for positioning like GPS, GNSS. The second section addresses the localization applications using the wireless sensor networks. Some techniques are introduced for localization systems, especially for indoor positioning, such as Ultra Wide Band (UWB), WIFI. The last section is dedicated to Coupled GPS and other sensors. Some results of simulations, implementation and tests are given to help readers grasp the presented techniques. This is an ideal book for students, PhD students, academics and engineers in the field of Communication, localization & Signal Processing, especially in indoor and outdoor localization domains

    Développement d'une méthode de géolocalisation à l'intérieur de bùtiments par classification des fingerprints GSM et fusion de données de capteurs embarqués

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    GPS has long been used for accurate and reliable outdoor localization, but it cannot operate in indoor environments, which suggests developing indoor localization methods that can provide seamless and ubiquitous services for mobile users.In this thesis, indoor localization is realized making use of received signal strength fingerprinting technique based on the existing GSM networks. A room is defined as the minimum location unit, and support vector machine are used as a mean to discriminate the rooms by classifying received signal strengths from very large number of GSM carriers. At the same time, multiple sensors, such as accelerometer and gyroscope, are widely available for modern mobile devices, which provide additional information that helps location determination. The hybrid approach that combines the GSM fingerprinting results with mobile sensor and building layout information using a particle filter provides a more accurate and fine-grained localization result.The results of experiments under realistic conditions demonstrate that correct room number can be obtained 94% of the time provided the derived model is used before significant received signal strength drift sets in. Furthermore, if the training data is sampled over a few days, the performance can remain stable exceeding 80% over a period of months, and can be further improved with various post-processing techniques. Moreover, including the mobile sensors allows the system to localize the mobile trajectory coordinates with high accuracy and reliability.L’objet de cette thĂšse est l’étude de la localisation et de la navigation Ă  l’intĂ©rieur de bĂątiments Ă  l’aide des signaux disponibles dans les systĂšmes mobiles cellulaires et, en particulier, les signaux GSM.Le systĂšme GPS est aujourd’hui couramment utilisĂ© en extĂ©rieur pour dĂ©terminer la position d’un objet, mais les signaux GPS ne sont pas adaptĂ©s Ă  la localisation en intĂ©rieurIci, la localisation en intĂ©rieur est obtenue Ă  partir de la technique des «empreintes» de puissance des signaux reçus sur les canaux utilisĂ©s par les rĂ©seaux GSM. Elle est rĂ©alisĂ©e Ă  l’échelle de la piĂšce. Une classification est effectuĂ©e Ă  partir de machines Ă  vecteurs supports et les descripteurs utilisĂ©s sont les puissances de toutes les porteuses GSM. D’autres capteurs physiques disponibles dans les tĂ©lĂ©phones portables fournissent des informations utiles pour dĂ©terminer la position ou le dĂ©placement de l’utilisateur. Celles-ci, ainsi que la cartographie de l’environnement, sont associĂ©es aux rĂ©sultats obtenus Ă  partir des «empreintes» GSM au sein de filtres particulaires afin d’obtenir une localisation plus prĂ©cise, et sous forme de coordonnĂ©es continues.Les rĂ©sultats obtenus montrent que l’utilisation des seules empreintes GSM permet de dĂ©terminer la piĂšce correcte dans 94% des cas sur une durĂ©e courte et que les performances restent stables pendant plusieurs mois, de l’ordre de 80%, si les donnĂ©es d’apprentissage sont enregistrĂ©es sur quelques jours. L’association de la cartographie du lieu et des informations issues des autres capteurs aux donnĂ©es de classification permettent d’obtenir les coordonnĂ©es de la trajectoire du systĂšme mobile avec une bonne prĂ©cision et une bonne fiabilitĂ©

    Mobile Ad-Hoc Networks

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    Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: vehicular ad-hoc networks, security and caching, TCP in ad-hoc networks and emerging applications. It is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks

    Algorithmes de localisation distribués en intérieur pour les réseaux sans fil avec la technologie IEEE 802.15.4

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    The Internet of Things is finally blooming through diverse applications, from home automation and monitoring to health tracking and quantified-self movement. Consumers deploy more and more low-rate and low-power connected devices that provide complex services. In this scenario, positioning these intelligent objects in their environment is necessary to provide geo-localized services, as well as to optimize the network operation. However, indoor positioning of devices using only their radio interface is still very imprecise. Indoor wireless localization techniques often deduce from the Radio frequency (RF) signal attenuation the distances that separate a mobile node from a set of reference points called landmarks. The received signal strength indicator (RSSI), which reflects this attenuation, is known in the literature to be inaccurate and unreliable when it comes to distance estimation, due to the complexity of indoor radio propagation (shadowing, multi-path fading). However, it is the only metric that will certainly be available in small and inexpensive smart objects. In this thesis, we therefore seek algorithmic solutions to the following problem: is it possible to achieve a fair localization using only the RSSI readings provided by low-quality hardware? To this extent, we first study the behavior of the RSSI, as reported by real hardware like IEEE 802.15.4 sensor nodes, in several indoor environments with different sizes and configurations , including a large scale wireless sensor network. Such experimental results confirm that the relationship between RSSI and distance depends on many factors; even the battery pack attached to the devices increases attenuation. In a second step, we demonstrate that the classical log-normal shadowing propagation model is not well adapted in indoor case, because of the RSSI values dispersion and its lack of obvious correlation with distance. We propose to correct the observed inconsistencies by developing algorithms to filter irrelevant samples. Such correction is performed by biasing the classical log-normal shadowing model to take into account the effects of multipath propagation. These heuristics significantly improved RSSI-based indoor localization accuracy results. We also introduce an RSSI-based positioning approach that uses a maximum likelihood estimator conjointly with a statistical model based on machine learning. In a third step, we propose an accurate distributed and cooperative RSSI-based localization algorithm that refines the set of positions estimated by a wireless node. This algorithm is composed of two on-line steps: a local update of positionÂżs set based on stochastic gradient descent on each new RSSI measurement at each sensor node. Then an asynchronous communication step allowing each sensor node to merge their common local estimates and obtain the agreement of the refined estimated positions. Such consensus approach is based on both a distributed local gradient step and a pairwise gossip protocol. This enables each sensor node to refine its initial estimated position as well as to build a local map of itself and its neighboring nodes. The proposed algorithm is compared to multilateration, Multi Dimensional Scaling (i.e. MDS) with modern majorization problem and classical MDS. Simulation as well as experimental results obtained on real testbeds lead to a centimeter-level accuracy. Both landmarks and blind nodes communicate in the way that the data processing and computation are performed by each sensor node without any central computation point, tedious calibration or intervention from a human.LÂżinternet des objets se dĂ©veloppe Ă  travers diverses applications telles que la domotique, la surveillance Ă  domicile, etc. Les consommateurs sÂżintĂ©ressent Ă  ces applications dont les objets interagissent avec des dispositifs de plus en plus petits et connectĂ©s. La localisation est une information clĂ© pour plusieurs services ainsi que pour lÂżoptimisation du fonctionnement du rĂ©seau. En environnement intĂ©rieur ou confinĂ©, elle a fait lÂżobjet de nombreuses Ă©tudes. Cependant, lÂżobtention dÂżune bonne prĂ©cision de localisation demeure une question difficile, non rĂ©solue. Cette thĂšse Ă©tudie le problĂšme de la localisation en environnement intĂ©rieur appliquĂ© aux rĂ©seaux sans fil avec lÂżutilisation unique de lÂżattĂ©nuation du signal. LÂżattĂ©nuation est mesurĂ©e par lÂżindicateur de lÂżintensitĂ© du signal reçu (RSSI). Le RSSI est connu dans la littĂ©rature comme Ă©tant imprĂ©cis et peu fiable en ce qui concerne lÂżestimation de la distance, du fait de la complexitĂ© de la propagation radio en intĂ©rieur : il sÂżagit des multiples trajets, le shadowing, le fading. Cependant, il est la seule mĂ©trique directement mesurable par les petits objets communicants et intelligents. Dans nos travaux, nous avons amĂ©liorĂ© la prĂ©cision des mesures du RSSI pour les rendre applicables Ă  lÂżenvironnement interne dans le but dÂżobtenir une meilleure localisation. Nous nous sommes Ă©galement intĂ©ressĂ©s Ă  lÂżimplĂ©mentation et au dĂ©ploiement de solutions algorithmiques relatifs au problĂšme suivant : est-il possible dÂżobtenir une meilleure prĂ©cision de la localisation en utilisant uniquement les mesures de RSSI fournies par les nÂżuds capteurs sans fil IEEE 802.15.4 ? Dans cette perspective, nous avons dÂżabord Ă©tudiĂ© le comportement du RSSI dans plusieurs environnements intĂ©rieurs de diffĂ©rentes tailles et selon plusieurs configurations , y compris un rĂ©seau de capteurs sans fil Ă  grande Ă©chelle (SensLAB). Pour expliquer les rĂ©sultats des mesures, nous avons caractĂ©risĂ© les objets communicants que nous utilisons, les nÂżuds capteurs Moteiv TMote Sky, par une sĂ©rie dÂżexpĂ©riences en chambre anĂ©choĂŻque. Les rĂ©sultats expĂ©rimentaux confirment que la relation entre le RSSI et la distance dĂ©pend de nombreux facteurs mĂȘme si la batterie intĂ©grĂ©e Ă  chaque nÂżud capteur produit une attĂ©nuation. Ensuite, nous avons dĂ©montrĂ© que le modĂšle de propagation log-normal shadowing nÂżest pas adaptĂ© en intĂ©rieur, en raison de la dispersion des valeurs de RSSI et du fait que celles-ci ne sont pas toujours dĂ©pendantes de la distance. Ces valeurs devraient ĂȘtre considĂ©rĂ©es sĂ©parĂ©ment en fonction de lÂżemplacement de chaque nÂżud capteur Ă©metteur. Nous avons proposĂ© des heuristiques pour corriger ces incohĂ©rences observĂ©es Ă  savoir les effets de la propagation par trajets multiples et les valeurs aberrantes. Nos rĂ©sultats expĂ©rimentaux ont confirmĂ© que nos algorithmes amĂ©liorent significativement la prĂ©cision de localisation en intĂ©rieur avec lÂżutilisation unique du RSSI. Enfin, nous avons Ă©tudiĂ© et proposĂ© un algorithme de localisation distribuĂ©, prĂ©cis et coopĂ©ratif qui passe Ă  l¿échelle et peu consommateur en termes de temps de calcul. Cet algorithme dÂżapproximation stochastique utilise la technique du RSSI tout en respectant les caractĂ©ristiques de lÂżinformatique embarquĂ©e des rĂ©seaux de capteurs sans fil. Il affine lÂżensemble des positions estimĂ©es par un nÂżud capteur sans fil. Notre approche a Ă©tĂ© comparĂ©e Ă  dÂżautres algorithmes distribuĂ©s de l¿état de lÂżart. Les rĂ©sultats issus des simulations et des expĂ©riences en environnements internes rĂ©els ont rĂ©vĂ©lĂ© une meilleure prĂ©cision de la localisation de notre algorithme distribuĂ©. LÂżerreur de localisation est de lÂżordre du centimĂštre sans aucun nÂżud ou unitĂ© centrale de traitement, ni de calibration fastidieuse ni dÂżintervention humaine

    Cooperative Radio Communications for Green Smart Environments

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    The demand for mobile connectivity is continuously increasing, and by 2020 Mobile and Wireless Communications will serve not only very dense populations of mobile phones and nomadic computers, but also the expected multiplicity of devices and sensors located in machines, vehicles, health systems and city infrastructures. Future Mobile Networks are then faced with many new scenarios and use cases, which will load the networks with different data traffic patterns, in new or shared spectrum bands, creating new specific requirements. This book addresses both the techniques to model, analyse and optimise the radio links and transmission systems in such scenarios, together with the most advanced radio access, resource management and mobile networking technologies. This text summarises the work performed by more than 500 researchers from more than 120 institutions in Europe, America and Asia, from both academia and industries, within the framework of the COST IC1004 Action on "Cooperative Radio Communications for Green and Smart Environments". The book will have appeal to graduates and researchers in the Radio Communications area, and also to engineers working in the Wireless industry. Topics discussed in this book include: ‱ Radio waves propagation phenomena in diverse urban, indoor, vehicular and body environments‱ Measurements, characterization, and modelling of radio channels beyond 4G networks‱ Key issues in Vehicle (V2X) communication‱ Wireless Body Area Networks, including specific Radio Channel Models for WBANs‱ Energy efficiency and resource management enhancements in Radio Access Networks‱ Definitions and models for the virtualised and cloud RAN architectures‱ Advances on feasible indoor localization and tracking techniques‱ Recent findings and innovations in antenna systems for communications‱ Physical Layer Network Coding for next generation wireless systems‱ Methods and techniques for MIMO Over the Air (OTA) testin

    Wireless Sensor Networks

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    The aim of this book is to present few important issues of WSNs, from the application, design and technology points of view. The book highlights power efficient design issues related to wireless sensor networks, the existing WSN applications, and discusses the research efforts being undertaken in this field which put the reader in good pace to be able to understand more advanced research and make a contribution in this field for themselves. It is believed that this book serves as a comprehensive reference for graduate and undergraduate senior students who seek to learn latest development in wireless sensor networks

    Proceedings of the Third Edition of the Annual Conference on Wireless On-demand Network Systems and Services (WONS 2006)

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    Ce fichier regroupe en un seul documents l'ensemble des articles accéptés pour la conférences WONS2006/http://citi.insa-lyon.fr/wons2006/index.htmlThis year, 56 papers were submitted. From the Open Call submissions we accepted 16 papers as full papers (up to 12 pages) and 8 papers as short papers (up to 6 pages). All the accepted papers will be presented orally in the Workshop sessions. More precisely, the selected papers have been organized in 7 session: Channel access and scheduling, Energy-aware Protocols, QoS in Mobile Ad-Hoc networks, Multihop Performance Issues, Wireless Internet, Applications and finally Security Issues. The papers (and authors) come from all parts of the world, confirming the international stature of this Workshop. The majority of the contributions are from Europe (France, Germany, Greece, Italy, Netherlands, Norway, Switzerland, UK). However, a significant number is from Australia, Brazil, Canada, Iran, Korea and USA. The proceedings also include two invited papers. We take this opportunity to thank all the authors who submitted their papers to WONS 2006. You helped make this event again a success

    Cooperative Radio Communications for Green Smart Environments

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    The demand for mobile connectivity is continuously increasing, and by 2020 Mobile and Wireless Communications will serve not only very dense populations of mobile phones and nomadic computers, but also the expected multiplicity of devices and sensors located in machines, vehicles, health systems and city infrastructures. Future Mobile Networks are then faced with many new scenarios and use cases, which will load the networks with different data traffic patterns, in new or shared spectrum bands, creating new specific requirements. This book addresses both the techniques to model, analyse and optimise the radio links and transmission systems in such scenarios, together with the most advanced radio access, resource management and mobile networking technologies. This text summarises the work performed by more than 500 researchers from more than 120 institutions in Europe, America and Asia, from both academia and industries, within the framework of the COST IC1004 Action on "Cooperative Radio Communications for Green and Smart Environments". The book will have appeal to graduates and researchers in the Radio Communications area, and also to engineers working in the Wireless industry. Topics discussed in this book include: ‱ Radio waves propagation phenomena in diverse urban, indoor, vehicular and body environments‱ Measurements, characterization, and modelling of radio channels beyond 4G networks‱ Key issues in Vehicle (V2X) communication‱ Wireless Body Area Networks, including specific Radio Channel Models for WBANs‱ Energy efficiency and resource management enhancements in Radio Access Networks‱ Definitions and models for the virtualised and cloud RAN architectures‱ Advances on feasible indoor localization and tracking techniques‱ Recent findings and innovations in antenna systems for communications‱ Physical Layer Network Coding for next generation wireless systems‱ Methods and techniques for MIMO Over the Air (OTA) testin

    Recent Advances in Wireless Communications and Networks

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    This book focuses on the current hottest issues from the lowest layers to the upper layers of wireless communication networks and provides "real-time" research progress on these issues. The authors have made every effort to systematically organize the information on these topics to make it easily accessible to readers of any level. This book also maintains the balance between current research results and their theoretical support. In this book, a variety of novel techniques in wireless communications and networks are investigated. The authors attempt to present these topics in detail. Insightful and reader-friendly descriptions are presented to nourish readers of any level, from practicing and knowledgeable communication engineers to beginning or professional researchers. All interested readers can easily find noteworthy materials in much greater detail than in previous publications and in the references cited in these chapters
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