Localization is critical to a number of wireless network applications. In many situations GPS is not suitable. This dissertation (i) develops novel localization schemes for wireless networks by explicitly incorporating mobility information and (ii) applies localization to physical analytics i.e., understanding shoppers' behavior within retail spaces by leveraging inertial sensors, Wi-Fi and vision enabled by smart glasses. More specifically, we first focus on multi-hop mobile networks, analyze real mobility traces and observe that they exhibit temporal stability and low-rank structure. Motivated by these observations, we develop novel localization algorithms to effectively capture and also adapt to different degrees of these properties. Using extensive simulations and testbed experiments, we demonstrate the accuracy and robustness of our new schemes. Second, we focus on localizing a single mobile node, which may not be connected with multiple nodes (e.g., without network connectivity or only connected with an access point). We propose trajectory-based localization using Wi-Fi or magnetic field measurements. We show that these measurements have the potential to uniquely identify a trajectory. We then develop a novel approach that leverages multi-level wavelet coefficients to first identify the trajectory and then localize to a point on the trajectory. We show that this approach is highly accurate and power efficient using indoor and outdoor experiments. Finally, localization is a critical step in enabling a lot of applications --- an important one is physical analytics. Physical analytics has the potential to provide deep-insight into shoppers' interests and activities and therefore better advertisements, recommendations and a better shopping experience. To enable physical analytics, we build ThirdEye system which first achieves zero-effort localization by leveraging emergent devices like the Google-Glass to build AutoLayout that fuses video, Wi-Fi, and inertial sensor data, to simultaneously localize the shoppers while also constructing and updating the product layout in a virtual coordinate space. Further, ThirdEye comprises of a range of schemes that use a combination of vision and inertial sensing to study mobile users' behavior while shopping, namely: walking, dwelling, gazing and reaching-out. We show the effectiveness of ThirdEye through an evaluation in two large retail stores in the United States. / text

A common problem in existing Search And Rescue (SAR) systems is that they must be activated by the missing person in order to work. This requires an awareness of the the risk of becoming distressed, which in many cases is not feasible. Furthermore, most of the localization systems require specialized hardware.In this thesis, the victim is assumed to wear a cellphone that could be located using readily available consumer electronics. A method of estimating the position of a transmitter, given radio signal measurements at different locations, is developed and verified with real and simulated data. A proof-of-concept system is built in which several users can jointly collect received signal strength data at different locations using mobile phones. The system analyzes the data in real-time and guides the users in the search by estimating the origin of the signal.An outdoor field test is conducted in which the searchers using the system are able to locate the hidden target phone without prior knowledge regarding the position. We are able to localize the victim with an accuracy of 10-20 meters in a timely manner using android smartphones. This shows the potential of a similar system in \abbrSAR scenarios. However, more work is needed to make the system viable in real scenarios and to remove some of the delimitations of the current implementation.

The wireless medium is lossy due to many reasons, such as signal attenuation, multi-path propagation, and collisions. Wireless losses degrade network throughput, reliability, and latency. The goal of this dissertation is to combat wireless losses by developing effective techniques and protocols across different network layers. First, a novel opportunistic routing protocol is developed to overcome wireless losses at the network layer. Opportunistic routing protocols exploit receiver diversity to route traffic in the face of loss. A distinctive feature of the protocol is the performance derived from its optimization can be achieved in real IEEE 802.11 networks. At its heart lies a simple yet realistic model of the network that captures wireless interference, losses, traffic, and MAC-induced dependencies. Then a model-driven optimization algorithm is designed to accurately optimize the end-to-end performance, and techniques are developed to map the resulting optimization solutions to practical routing configurations. Its effectiveness is demonstrated using simulation and testbed experiments. Second, an efficient retransmission scheme (ER) is developed at the link layer for wireless networks. Instead of retransmitting lost packets in their original forms, ER codes packets lost at different destinations and uses a single retransmission to potentially recover multiple packet losses. A simple and practical protocol is developed to realize the idea, and it is evaluated using simulation and testbed experiments to demonstrate its effectiveness. Third, detailed measurement traces are collected to understand wireless losses in dynamic and mobile environments. Existing wireless drivers are modified to enable the logging and analysis of network activity under varying end-host configurations. The results indicate that mobile clients can suffer from consecutive packet losses, or burst errors. The burst errors are then analyzed in more detail to gain further insights into the problem. With these insights, recommendations for future research directions to mitigate loss in mobile environments are presented. / text

Η τεχνολογία Wi-Fi χρησιμοποιείται για να συνδέει ασύρματα συσκευές μεγάλης ισχύος και υψηλής ταχύτητας όπως είναι οι σταθεροί και οι φορητοί υπολογιστές, δημιουργώντας έτσι ένα μεγάλο και γρήγορο δίκτυο τοπικού εύρους ζώνης (Local Area Network - LAN). Σε ένα τέτοιο δίκτυο μπορούν να συνδεθούν υπολογιστές, PDAs και άλλες συσκευές χρησιμοποιώντας τα σημεία πρόσβασης (Access Points) με σκοπό την σύνδεση στο διαδίκτυο, την μεταφορά δεδομένων μεταξύ τους και άλλες εφαρμογές. Ενδιαφέρον παρουσιάζει η αυξημένη ανάγκη για εφαρμογές οι οποίες να είναι σε θέση να χρησιμοποιούν την ασύρματη τεχνολογία για να εντοπίσουν την θέση των συσκευών των χρηστών με σκοπό την εκμετάλλευση της ίδιας της πληροφορίας της θέσης και την αποστολή στους χρήστες διαφόρων δεδομένων-πληροφοριών. Μια τέτοια τεχνολογία είναι το γνωστό GPS (Global Positioning System), το οποίο όμως είναι λειτουργικό σε εξωτερικούς χώρους. Την ανάγκη για εντοπισμό θέσης χρήστη σε εσωτερικούς χώρους προσπαθεί να καλύψει η εργασία αυτή. Η διπλωματική αυτή εργασία σκοπεύει στην μελέτη της ασύρματης τεχνολογίας Wi-Fi με σκοπό την υλοποίηση εφαρμογής η οποία θα παρακολουθεί την κινητικότητα των χρηστών σε ένα Ασύρματο δίκτυο Wi-Fi τοπικού εύρου ζώνης (LAN) με σκοπό την περισυλλογή πληροφοριών σχετικών με την κίνηση των χρηστών και την ανταλλαγή δεδομένων. Αρχικά γίνεται μια ανάλυση των ειδών δικτύων και δικτυακών τοπολογιών και έπειτα μια παρουσίαση του προτύπου της IEEE 802.11, το αποκαλούμενο και χάριν απλότητας Wi-Fi (Wireless Fidelity). Η φύση των ασύρματων δικτύων επιτρέπει την πρόσβαση στους δικτυακούς πόρους και την παροχή υπηρεσιών χωρίς την ανάγκη καλωδίωσης. Η ιδιαιτερότητα αυτή των ασυρμάτων δικτύων πέρα από τα πλεονεκτήματα τα οποία παρουσιάζει, εμφανίζει και αδυναμίες και πιο συγκεκριμένα αδυναμίες ασφάλειας. Στην εργασία αυτή παρουσιάζονται οι πιο γνωστές αδυναμίες ασφάλειας καθώς και τρόποι αντιμετώπισης αυτών. Επίσης παρουσιάζονται και τα κυριότερα εργαλεία προσβολής της ασφάλειας σε ασύρματα Wi-Fi δίκτυα. Τέλος παρουσιάζονται οι προϋπάρχουσες και κυριότερες τεχνολογίες εντοπισμού θέσης χρήστη. Όσον αφορά το πρακτικό κομμάτι της εργασίας αυτής, υλοποιείται εφαρμογή εντοπισμού θέσης χρήστη σε ασύρματα Wi-Fi δίκτυα η οποία κάνει χρήση της ισχύος του σήματος σταθερών σημείων αναφοράς έτσι ώστε να προσδιοριστεί με ακρίβεια η θέση του χρήστη. / -

This thesis is a critical edition of "al-Durr al-Maknūn fī al-Ma'āthir al-Māḍiya min al-Ǫurūn" (DUR.) by the Iraqi historian, Yāsīn Efendi al-Khaṭīb al-'Umarī al-Mawṣilī, 1158-1234 A.H. = 1745- 1818 A. D. covering the years 920 A. H. -1226 A. H. (= 1514/1515 A. D.- 1811/1812 A. D. ). The present thesis consists of three parts, and is divided into three volumes. The first part (Vol. I, Introduction and Notes) contains the introduction to DUR., in four chapters, with a supplement. Chapter one is composed of two sections I the first of which deals with the author's personality and his biography: name and nisba , titles and kunya, birth, background, knowledge, character, mystical leanings, social standing, and his death. The second section deals with the author's family (the 'Umarī's in MosuI). The second chapter is divided into two sections, the first is a list of all the author's works; historical, poetical, and literary, and his Naskhiyyāt. The second section is a study of the author's historical works. This study deals analytically with each work in turn. The third chapter is a study of the relevant MSS. The historical structure of these MSS is examined, and the MSS of DUR. are described individually; orthography and the style of the author…etc. are also investigated. The fourth chapter is a study of the text of DUR. It contains two sections. In the first section, peculiarities of the text are outlined as are the name of the work, the sources, the work as history, its literary forms, geographical elements and economic information. Section two comprises a study of the historical content which is embodied in this thesis under the following headings: a) Biographical material, b) Annals, c) Contemporary chronicles, d) Local History. Historical content of the biographical material is analysed, as also is the historical material in other fields. The annals cover: 1) The Ottoman conflict with Iran, 2) Eastern Europe, 3) The Mediterranean, 4) Russia and Poland. Also covered in the contemporary chronicles are: 1) The French Revolution, 2) Napoleon Bonaparte, 3) The Ashrāf of Mecca, 4) The Syrian provinces,S) Salafiyya and Wahhābiyya, 6) Istanbul, 7) Iraq. Local historical subjects covered are: 1) The local powers in the Middle East during the 18th century, 2) Iraq during the 18th century, and 3) The local history of Mosul. The last subject is studied in detail because it is of considerable importance in DUR. which contains full details of the Jalīlī house in Mosul during the 18th century. The additional supplement deals with the methods employed in editing DUR. This volume also contains appendices, tables, diagrams, maps, lists and bibliographies. Of these appendices attention is drawn to “Appe No. 1": (= Notes to the Text) which contains explanatory comments and emendations. The second part of the thesis (Vol. II Text) contains the text of the first version of DUR. (= DUR. 1 : MSS v and pl. The third part of the thesis (Vol. III, "Apparatus Criticus") contains a comparison of the DUR. 1 and DUR. 2 MSS (= v, p, Bn, B, BR)i it also contains the additional material from DUR. 2 (= MSS Bn, B, BR). In this volume, there is also a supplement of additional historical material, covering the period 1218-1226 A.H. (= 1803-1811 A.D.), taken from DUR. 2 (= MS Bn). This is compared with MSS Band BR.

Darbe nagrinėjami bevieliai kompiuteriniai tinklai Wi-Fi ir jų problemos. Nustatomos kelios iš pagrindinių bevielių tinklų problemų. Radijo modulio veikimo režimas yra halfduplex, nepakankamas naudingo srauto perdavimas, srauto klasifikacijos ir prioritetizacijos nebuvimas mano manymu yra pagrindinės bevielio ryšio įrenginių problemos. Bandoma ieškoti problemų sprendimo variantus. Vienas iš galimų sprendimų yra sukurti bevielio ryšio įrenginį, kuris turės šių problemų realizaciją. Ieškoma įrenginiui sukurti būtinų detalių, tokių kaip platforma, radijo modulis, antena ir kitos būtinos detalės. Pirmiausia pasirenkama PC-based platforma dėl to kad turi didesnį produktyvumą ir yra universalesnė. Vienareikšmiškai pasirenkamas 5 GHz radijo dažnis, kadangi įrenginys bus testuojamas ir naudojamas realaus tinklo infrastruktūroje Vilniaus mieste. 2,4 GHz dažnio ruožo naudojimo buvo atsisakyta dėl stipraus užterštumo. Kaip paaiškėjo analizuojamos problemos yra susijusios viena su kita ir reikalauja kompleksinio sprendimo. Buvo nustatyta problemų prigimtis ir jos sprendimas: bendro srauto ribojimas, srautų pagal paskirtį atskyrimas ir jų ribojimas. Ieškomos standartinės ir nestandartinės problemų sprendimo priemonės, tobulinamos, tarpusavyje suderintos ir pritaikytos kuriamai sistemai. Tik realioje tinklo infrastruktūroje su realiais vartotojų generuojamais srautais pavyko nustatyti ir pašalinti trukumus. / This work is an analysis of wireless computer networks Wi-Fi and their problems. Few main wireless networks problems established. Radio module working mode is halfduplex, insufficient transfers of useful data stream, absence of stream classification and prioritisation in my opinion is a main problems of wireless devices. Attempt to search solution of the problems. One of the possible solutions is making an own wireless device witch will have realisation of this problems. Searching for necessary parts to make a device, such as platform, radio module, antenna ant other necessary parts. First of all I have chosen PC-based platform because it has a good productivity ant is more universal. Unambiguous choice was 5 GHz radio frequency, because device will be tested and used in real network infrastructure of Vilnius city. The use of 2,4 GHz radio frequency was rejected because of high radio pollution. It emerged that analysed problems are associated one with another and needs complex solution. Was found nature of this problems and its solutions: total bandwidth shaping, separation of different streams by purpose and their shaping. Searching for standard and nonstandard means to solve such problems, modifying, matching together and adjust to created system. Only in real network infrastructure with real user generated streams was able find and eliminate limitations.

Les réseaux sans fil sont en plein développement du fait de la flexibilité de leur interface, qui permet aux utilisateurs de se communiquer directement entre eux ou de se connecter facilement à Internet en onde radio sans mettre en place préalablement d'infrastructures lourdes, telles que des câbles filaires. Parmi les différentes technologies de réseaux sans fil, l'IEEE 802.11/Wi-Fi est devenu une technologie plus connue et plus utilisée pour construire des réseaux sans fil à haut débit dans une zone à forte concentration d'utilisateurs, telle que les aéroports, les campus ou les sites industriels. L'engouement pour les réseaux sans fil et notamment pour les réseaux Wi-Fi a fait émerger de nouvelles nécessités, tel que se déplace dans les réseaux sans fil tout en restant connecté à Internet. Dans les réseaux sans fil, le déplacement d'un utilisateur implique parfois un changement de Point d'accès (AP) au réseau. On désigne généralement ce fait un handover de niveau 2, du fait que le changement d'AP n'implique que les deux premières couches du modèle OSI. Si les deux APs se situent dans des réseaux différents, le changement d'AP implique aussi le changement de réseau pour cet utilisateur. On dénomme généralement cette situation un handover de niveau 3, par le fait que cet utilisateur devrait changer son réseau d'attachement et son adresse IP pour maintenir la connexion à Internet et que ce changement intervient sur la couche réseau du model OSI. La procédure du handover de niveau 2 dans les réseaux Wi-Fi est gérée par la norme IEEE 802.11 et celle de niveau 3 est gérée par le protocole IP Mobile. Le protocole IP Mobile est un protocole standardisé par l'IETF qui permet à l'utilisateur de maintenir ses communications en cours et de rester connecté à Internet tout en masquant d'une manière transparente le changement de réseau. Ainsi, l'utilisateur peut se déplace dans les réseaux Wi-Fi tout en maintenant les communications en cours et restant connecté à Internet grâce à la norme IEEE 802.11 et au protocole IP Mobile. Cependant, le délai introduit par ces deux procédures du handover est trop long, les communications en cours sont interrompus pendant ces procédures, naturellement, cela ne peut pas répondre aux exigences qualitatives des applications temps réel comme la vidéo conférence ou la voix sur IP. Diverses propositions qui ont été faites pour réduire le délai de ces procédures du handover et améliorer leur performance. Cependant, ces propositions sont soit imparfaites, soit non-implémentables à cause de leur complexité. En partant du principe que les réseaux Wi-Fi et les routeurs d'accès sont déjà massivement implantés dans le monde universitaire et dans les entreprises, nous proposons d'ajouter une nouvelle fonctionnalité, appelé E-HCF (Extended Handover Control Function) dans un routeur sans modifier les autres équipements du réseau. Le routeur pourvu de cette fonctionnalité est dénommé le routeur E-HCF. Pour réduire le délai des procédures du handover, la fonctionnalité E-HCF permet au routeur de générer une topologie des APs en utilisant la théorie des graphes de voisinage et de maintenir un pool d'adresses IP disponibles dans sa base de données. Quand le Nœud mobile (MN) a besoin de changer son AP, le routeur E-HCF peut proposer au MN une liste des APs potentiellement utilisables qui sont choisis et classés par un algorithme de sélection et de classement que nous avons élaboré dans la thèse. Si le changement d'AP implique un changement de réseau, le MN doit changer d'adresse IP. Dans ce cas, le routeur E-HCF peut attribuer une adresse IP unique à ce MN. Le MN peut donc utiliser cette adresse sans exécuter la phase d'Auto-configuration d'adresses ni exécuter la procédure de Détection d'adresse dupliquée. Avec cette nouvelle fonctionnalité E-HCF, nous pouvons réduire le délai des procédures du handover de quelques secondes à une centaine de millisecondes. Pour réduire la perte de paquets due aux procédures du handover, nous proposons de modifier le protocole IPv6 Mobile. Le MN met fin à l'association entre son adresse mère et son adresse temporaire avec l'Agent mère (HA) et le Nœud correspondant (CN) avant de procéder la procédure du handover. Par ce moyen, le HA peut intercepter les paquets destinés à l'adresse mère du MN et les garder dans son mémoire tampon. Une fois le MN met à jour l'association entre son adresse mère et sa nouvelle adresse temporaire avec le HA, le HA peut envoyer les paquets stockés dans son mémoire de tampon au MN. Il intercepte et redirige également les paquets du CN ou du MN vers la nouvelle adresse temporaire du MN ou vers les adresses du CN respectivement pendant la phase de mise à jour d'association. Avec cette méthode, nous pouvons limiter la perte de paquets et garantir un délai acceptable. Pour étayer notre proposition, nous avons utilisé le simulateur OPNET pour simuler le déroulement des procédures du handover dans les réseaux Wi-Fi géré par la méthode E-HCF et celui géré par le protocole IPv6 Mobile. Les résultats obtenus montrent qu'avec notre méthode E-HCF, nous pouvons garantir un délai acceptable et limiter la perte des paquets. Ensuite, nous avons également validé notre méthode E-HCF avec la norme IEEE 802.11e qui supporte la Qualité de Service (QoS). Avec le support de QoS, les résultats obtenus par simulation illustrent les améliorations des performances significatives pour les communications de bout en bout dans les réseaux chargés. Nos travaux de recherche ont donné lieu à trois publications dans les conférences internationales et un article dans la revue internationale (Voir Index)

Today, positioning with GPS and the advantages this entails are almost infinitive, which means that the technology can be utilized in a variety of applications. Unfortunately, there exists a lot of limitations in conjunction with the signals from the GPS can’t reach inside e.g. buildings or underground. This means that an alternative solution that works indoors needs to be developed. The report presents the four most common radio-based technologies, Bluetooth,Wi-Fi, UWB and RFID, which can be used to determine a position. These all have different advantages in cost, accuracy and latency, which means that there exist a number of different applications. The radio-based methods use the measurement techniques, RSSI, TOA, TDOA, Cell-ID, PD or AOA to gather data. The choice of measurement technique is mainly dependent of which radio-based method being used, since their accuracy depends on the quality of the measurements and the size of the detection area, which means that all measurement techniques have different advantages and disadvantages. The measurement data is processed with one of the positioning methods, LS, NLS, ML, Cell-ID, WC or FP, to estimate a position. The choice of positioning method also depends on the quality of the measurements in combination with the size of the detection area. To evaluate the different radio-based methods together with measurement techniques and positioning methods, accuracy, latency and cost are being compared. This is used as the basis for the choice of positioning method, since a general solution can get summarized by finding the least expensive approach which can estimate an unknown position with sufficiently high accuracy.

During the last century, the significant increase in electricity demand, and its consequences, has appeared as a serious concern for the utility companies, but no essential change has been applied to the conventional power grid infrastructure till now. Recently, researchers have identified efficient control and power distribution mechanisms as the immediate challenges for conventional power grids. Hence, the next step for conventional power grid toward Smart Grid is to provide energy efficiency management along with higher reliability via smart services, in which the application of Information and Communication Technology (ICT) is inevitable. ICT introduces powerful tools to comply with the smart grid requirements. Among various ICT properties, the telecommunication network plays a key role for providing a secure infrastructure. The two-way digital communication system provides an interaction between energy suppliers and consumers for managing, controlling and optimizing energy distribution. We can also define the smart grid as a two-way flow of energy and control information, where the electricity consumers can generate energy using green energy resources. The main objective of this thesis is to select an effective communication infrastructure to support the smart grid services by considering wireless and optical communication technologies. Fiber-wireless (FiWi) networks are considered as a potential solution to provide a fast and reliable network backbone with the optical access network integration and the flexibility and mobility of the wireless network. Therefore, we adopt the integration of the wireless sensor network (WSN) to Ethernet Passive Optical Network (EPON) as a broadband access network to transmit smart meter data along with the Fiber To The Home/Building/Curb (FTTX) traffic through the shared fiber. Finally, we present and analyze the simulation results for the aforementioned infrastructure based on our adopted priority-based FTTX-WSN integration model.

No description available.