Localisation en intérieur et gestion de la mobilité dans les réseaux sans fils hétérogènes émergents

Au cours des dernières décennies, nous avons été témoins d'une évolution considérable dans l'informatique mobile, réseau sans fil et des appareils portatifs. Dans les réseaux de communication à venir, les utilisateurs devraient être encore plus mobiles exigeant une connectivité omniprésente à différentes applications qui seront de préférence au courant de leur contexte. Certes, les informations de localisation dans le cadre de leur contexte est d'une importance primordiale à la fois la demande et les perspectives du réseau. Depuis l'application ou de point de vue utilisateur, la fourniture de services peut mettre à jour si l'adaptation au contexte de l'utilisateur est activée. Du point de vue du réseau, des fonctionnalités telles que le routage, la gestion de transfert, l'allocation des ressources et d'autres peuvent également bénéficier si l'emplacement de l'utilisateur peuvent être suivis ou même prédit. Dans ce contexte, nous nous concentrons notre attention sur la localisation à l'intérieur et de la prévision transfert qui sont des composants indispensables à la réussite ultime de l'ère de la communication omniprésente envisagé. Alors que les systèmes de positionnement en plein air ont déjà prouvé leur potentiel dans un large éventail d'applications commerciales, le chemin vers un système de localisation à l'intérieur de succès est reconnu pour être beaucoup plus difficile, principalement en raison des caractéristiques difficiles à l'intérieur et l'exigence d'une plus grande précision. De même, la gestion de transfert dans le futur des réseaux hétérogènes sans fil est beaucoup plus difficile que dans les réseaux traditionnels homogènes. Régimes de procédure de transfert doit être sans faille pour la réunion strictes de qualité de service (QoS) des applications futures et fonctionnel malgré la diversité des caractéristiques de fonctionnement des différentes technologies. En outre, les décisions transfert devraient être suffisamment souples pour tenir compte des préférences utilisateur d'un large éventail de critères proposés par toutes les technologies. L'objectif principal de cette thèse est de mettre au point précis, l'heure et l'emplacement de puissance et de systèmes efficaces de gestion de transfert afin de mieux satisfaire applications sensibles au contexte et mobiles. Pour obtenir une localisation à l'intérieur, le potentiel de réseau local sans fil (WLAN) et Radio Frequency Identification (RFID) que l'emplacement autonome technologies de détection sont d'abord étudiés par des essais plusieurs algorithmes et paramètres dans un banc d'essai expérimental réel ou par de nombreuses simulations, alors que leurs lacunes sont également été identifiés. Leur intégration dans une architecture commune est alors proposée afin de combiner leurs principaux avantages et surmonter leurs limitations. La supériorité des performances du système de synergie sur le stand alone homologues est validée par une analyse approfondie. En ce qui concerne la tâche de gestion transfert, nous repérer que la sensibilité au contexte peut aussi améliorer la fonctionnalité du réseau. En conséquence, deux de tels systèmes qui utilisent l'information obtenue à partir des systèmes de localisation sont proposées. Le premier schéma repose sur un déploiement tag RFID, comme notre architecture de positionnement RFID, et en suivant la scène WLAN analyse du concept de positionnement, prédit l'emplacement réseau de la prochaine couche, c'est à dire le prochain point de fixation sur le réseau. Le second régime repose sur une approche intégrée RFID et sans fil de capteur / actionneur Network (WSAN) de déploiement pour la localisation des utilisateurs physiques et par la suite pour prédire la prochaine leur point de transfert à deux couches de liaison et le réseau. Etre indépendant de la technologie d'accès sans fil principe sous-jacent, les deux régimes peuvent être facilement mises en œuvre dans des réseaux hétérogènes [...]Over the last few decades, we have been witnessing a tremendous evolution in mobile computing, wireless networking and hand-held devices. In the future communication networks, users are anticipated to become even more mobile demanding for ubiquitous connectivity to different applications which will be preferably aware of their context. Admittedly, location information as part of their context is of paramount importance from both application and network perspectives. From application or user point of view, service provision can upgrade if adaptation to the user's context is enabled. From network point of view, functionalities such as routing, handoff management, resource allocation and others can also benefit if user's location can be tracked or even predicted. Within this context, we focus our attention on indoor localization and handoff prediction which are indispensable components towards the ultimate success of the envisioned pervasive communication era. While outdoor positioning systems have already proven their potential in a wide range of commercial applications, the path towards a successful indoor location system is recognized to be much more difficult, mainly due to the harsh indoor characteristics and requirement for higher accuracy. Similarly, handoff management in the future heterogeneous wireless networks is much more challenging than in traditional homogeneous networks. Handoff schemes must be seamless for meeting strict Quality of Service (QoS) requirements of the future applications and functional despite the diversity of operation features of the different technologies. In addition, handoff decisions should be flexible enough to accommodate user preferences from a wide range of criteria offered by all technologies. The main objective of this thesis is to devise accurate, time and power efficient location and handoff management systems in order to satisfy better context-aware and mobile applications. For indoor localization, the potential of Wireless Local Area Network (WLAN) and Radio Frequency Identification (RFID) technologies as standalone location sensing technologies are first studied by testing several algorithms and metrics in a real experimental testbed or by extensive simulations, while their shortcomings are also identified. Their integration in a common architecture is then proposed in order to combine their key benefits and overcome their limitations. The performance superiority of the synergetic system over the stand alone counterparts is validated via extensive analysis. Regarding the handoff management task, we pinpoint that context awareness can also enhance the network functionality. Consequently, two such schemes which utilize information obtained from localization systems are proposed. The first scheme relies on a RFID tag deployment, alike our RFID positioning architecture, and by following the WLAN scene analysis positioning concept, predicts the next network layer location, i.e. the next point of attachment to the network. The second scheme relies on an integrated RFID and Wireless Sensor/Actuator Network (WSAN) deployment for tracking the users' physical location and subsequently for predicting next their handoff point at both link and network layers. Being independent of the underlying principle wireless access technology, both schemes can be easily implemented in heterogeneous networks. Performance evaluation results demonstrate the advantages of the proposed schemes over the standard protocols regarding prediction accuracy, time latency and energy savingsEVRY-INT (912282302) / SudocSudocFranceF

Integrating the Supply Chain with RFID: A Technical and Business Analysis

This paper presents an in-depth analysis of the technical and business implications of adopting Radio Frequency Identification (RFID) in organizational settings. The year 2004 marked a significant shift toward adopting RFID because of mandates by large retailers and government organizations. The use of RFID technology is expected to increase rapidly in the next few years. At present, however, initial barriers against widespread adoption include standards, interoperability, costs, forward compatibility, and lack of familiarity. This paper describes basic components of an RFID system including tags, readers, and antennas and how they work together using an integrated supply chain model. Our analysis suggests that business needs to overcome human resource scarcity, security, legal and financial challenges and make informed decision regarding standards and process reengineering. The technology is not fully mature and suffers from issues of attenuation and interference. A laboratory experiment conducted by the authors\u27 shows that the middleware is not yet at a plug-and-play stage, which means that initial adopters need to spend considerable effort to integrate RFID into their existing business processes. Appendices contain a glossary of common RFID terms, a list of RFID vendors and detailed findings of the laboratory experiment. NOTE: BECAUSE OF THE ILLUSTRATIONS USED, THIS ARTICLE IS LONG; APPROXIMATELY 850KB IN BOTH JOURNAL AND ARTICLE VERSIO

An Energy Aware and Secure MAC Protocol for Tackling Denial of Sleep Attacks in Wireless Sensor Networks

Wireless sensor networks which form part of the core for the Internet of Things consist of resource constrained sensors that are usually powered by batteries. Therefore, careful energy awareness is essential when working with these devices. Indeed,the introduction of security techniques such as authentication and encryption, to ensure confidentiality and integrity of data, can place higher energy load on the sensors. However, the absence of security protection c ould give room for energy drain attacks such as denial of sleep attacks which have a higher negative impact on the life span ( of the sensors than the presence of security features. This thesis, therefore, focuses on tackling denial of sleep attacks from two perspectives A security perspective and an energy efficiency perspective. The security perspective involves evaluating and ranking a number of security based techniques to curbing denial of sleep attacks. The energy efficiency perspective, on the other hand, involves exploring duty cycling and simulating three Media Access Control ( protocols Sensor MAC, Timeout MAC andTunableMAC under different network sizes and measuring different parameters such as the Received Signal Strength RSSI) and Link Quality Indicator ( Transmit power, throughput and energy efficiency Duty cycling happens to be one of the major techniques for conserving energy in wireless sensor networks and this research aims to answer questions with regards to the effect of duty cycles on the energy efficiency as well as the throughput of three duty cycle protocols Sensor MAC ( Timeout MAC ( and TunableMAC in addition to creating a novel MAC protocol that is also more resilient to denial of sleep a ttacks than existing protocols. The main contributions to knowledge from this thesis are the developed framework used for evaluation of existing denial of sleep attack solutions and the algorithms which fuel the other contribution to knowledge a newly developed protocol tested on the Castalia Simulator on the OMNET++ platform. The new protocol has been compared with existing protocols and has been found to have significant improvement in energy efficiency and also better resilience to denial of sleep at tacks Part of this research has been published Two conference publications in IEEE Explore and one workshop paper

Passive Wireless Saw Sensors With New And Novel Reflector Structures Design And Applications

Surface acoustic wave (SAW) devices are a solution for today’s ever growing need for passive wireless sensors. Orthogonal frequency coding (OFC) together with time division multiplexing (TDM) provides a large number of codes and coding algorithms producing devices that have excellent collision properties. Novel SAW noise-like re- flector (NLR) structures with pulse position modulation (PPM) are shown to exhibit good auto- and cross-correlation, and anti-collision properties. Multi-track, multi-transducer approaches yield devices with adjustable input impedances and enhanced collision properties for OFC TDM SAW sensor devices. Each track-transducer is designed for optimum performance for loss, coding, and chip reflectivity. Experimental results and theoretical predictions confirm a constant Q for SAW transducers for a given operational bandwidth, independent of device and transducer embodiment. Results on these new NLR SAW structures and devices along with a new novel 915 MHz transceiver based on a software radio approach was designed, built, and analyzed. Passive wireless SAW temperature sensors were interrogated and demodulated in a spread spectrum correlator system using a new adaptive filter. The first-ever SAW OFC four-sensor operation was demonstrated at a distance of 1 meter and a single sensor was shown to operate up to 3 meters. Comments on future work and directions are also presente

Personal Privacy Protection within Pervasive RFID Environments

Recent advancements in location tracking technologies have increased the threat to an individual\u27s personal privacy. Radio frequency identification (RFID) technology allows for the identification and potentially continuous tracking of an object or individual, without obtaining the individual\u27s consent or even awareness that the tracking is taking place. Although many positive applications for RFID technology exist, for example in the commercial sector and law enforcement, the potential for abuse in the collection and use of personal information through this technology also exists. Location data linked to other types of personal information allows not only the detection of past spatial travel and activity patterns, but also inferences regarding past and future behavior and preferences. Legislative and technological solutions to deal with the increased privacy threat raised by this and similar tracking technologies have been proposed. Such approaches in isolation have significant limitations. This thesis hypothesizes that an approach may be developed with high potential for sufficiently protecting individual privacy in the use of RFID technologies while also strongly supporting marketplace uses of such tags. The research develops and investigates the limits of approaches that might be us,ed to protect privacy in pervasive RFID surveillance environments. The conclusion is ultimately reached that an approach facilitating individual control over the linking of unique RFID tag ID numbers to personal identity implemented though a combination of legal controls and technological capabilities would be a highly desirable option in balancing the interests of both the commercial sector and the information privacy interests of individuals. The specific model developed is responsive to the core ethical principle of autonomy of the individual and as such is also intended to be more responsive to the needs of individual consumers. The technological approach proposed integrated with enabling privacy legislation and private contract law to enable interactive alteration of privacy preferences should result in marketplace solutions acceptable to both potential commercial users and those being tracked

Personal Privacy Protection within Pervasive RFID Environments

Recent advancements in location tracking technologies have increased the threat to an individual\u27s personal privacy. Radio frequency identification (RFID) technology allows for the identification and potentially continuous tracking of an object or individual, without obtaining the individual\u27s consent or even awareness that the tracking is taking place. Although many positive applications for RFID technology exist, for example in the commercial sector and law enforcement, the potential for abuse in the collection and use of personal information through this technology also exists. Location data linked to other types of personal information allows not only the detection of past spatial travel and activity patterns, but also inferences regarding past and future behavior and preferences. Legislative and technological solutions to deal with the increased privacy threat raised by this and similar tracking technologies have been proposed. Such approaches in isolation have significant limitations. This thesis hypothesizes that an approach may be developed with high potential for sufficiently protecting individual privacy in the use of RFID technologies while also strongly supporting marketplace uses of such tags. The research develops and investigates the limits of approaches that might be us,ed to protect privacy in pervasive RFID surveillance environments. The conclusion is ultimately reached that an approach facilitating individual control over the linking of unique RFID tag ID numbers to personal identity implemented though a combination of legal controls and technological capabilities would be a highly desirable option in balancing the interests of both the commercial sector and the information privacy interests of individuals. The specific model developed is responsive to the core ethical principle of autonomy of the individual and as such is also intended to be more responsive to the needs of individual consumers. The technological approach proposed integrated with enabling privacy legislation and private contract law to enable interactive alteration of privacy preferences should result in marketplace solutions acceptable to both potential commercial users and those being tracked

Distributed Wireless Algorithms for RFID Systems: Grouping Proofs and Cardinality Estimation

The breadth and depth of the use of Radio Frequency Identification (RFID) are becoming more substantial. RFID is a technology useful for identifying unique items through radio waves. We design algorithms on RFID-based systems for the Grouping Proof and Cardinality Estimation problems. A grouping-proof protocol is evidence that a reader simultaneously scanned the RFID tags in a group. In many practical scenarios, grouping-proofs greatly expand the potential of RFID-based systems such as supply chain applications, simultaneous scanning of multiple forms of IDs in banks or airports, and government paperwork. The design of RFID grouping-proofs that provide optimal security, privacy, and efficiency is largely an open area, with challenging problems including robust privacy mechanisms, addressing completeness and incompleteness (missing tags), and allowing dynamic groups definitions. In this work we present three variations of grouping-proof protocols that implement our mechanisms to overcome these challenges. Cardinality estimation is for the reader to determine the number of tags in its communication range. Speed and accuracy are important goals. Many practical applications need an accurate and anonymous estimation of the number of tagged objects. Examples include intelligent transportation and stadium management. We provide an optimal estimation algorithm template for cardinality estimation that works for a {0,1,e} channel, which extends to most estimators and ,possibly, a high resolution {0,1,...,k-1,e} channel

Advanced Radio Frequency Identification Design and Applications

Radio Frequency Identification (RFID) is a modern wireless data transmission and reception technique for applications including automatic identification, asset tracking and security surveillance. This book focuses on the advances in RFID tag antenna and ASIC design, novel chipless RFID tag design, security protocol enhancements along with some novel applications of RFID

Realistic chipless RFID: protocol, encoding and system latency

Chiplose Identifikation über Funkfrequenzen, RFID (engl., Radio Frequency IDentification) ist eine vielversprechende Technology, der man die Fähigkeit zuschreibt, in naher Zukunft den optischen Barcode zu ersetzen. Letztgenannter hat Einschränkungen durch i) RFID Tags sind bei nicht vorhandener Sichtverbindung (engl. Non-Line-Of-Sight, NLOS) auch nicht lesbar; ii) das Scannen der Barcodes benötigt in den meisten Fällen manuelles Eingreifen; iii) es ist unmöglich mehrere Barcodes gleichzeitig auszulesen; iv) und als Folge davon entsprechende Verzögerungen beim Auslesen größerer Mengen von Barcodes, da alle einzeln gescannt werden müssen. Die Beiträge der vorliegenden Dissertation konzentrieren sich auf drei Schwerpunkte von frequenzcodierten (engl. frequency coded, FC) chiplosen RFID Systemen. Der erste Schwerpunkt ist die gleichzeitige Identifikation von mehreren RFID Tags und kümmert sich um den Fall, dass sich mehrere RFID Tags in der Lesezone des RFID Lesegerätes befinden. Der zweite Aspekt betrifft die Verzögerung des Systems, die Zeit, das Lesegerät zum Identifizieren der RFID Tags benötigt. Und drittens die Coding Kapazität des Systems, sie ist verantwortlich für die zu erreichende Bittiefe des RFID Systems. Ein real umsetzbares RFID System erfordert Lösungen in allen drei Aspekten. Da chiplose RFID Tags keine integrierten Schaltungen (ICs) und somit auch keine Speicherbausteine besitzen, ist die Anzahl der auf dem RFID Tag speicherbaren Bits begrenzt. Und als Folge davon sind die Standards und Protokolle, die für die herkömmlichen chipbehafteten RFID Systeme entwickelt worden, nicht auf chiplose RFID Systeme übertragbar. Das wesentliche Ziel des ersten Beitrages ist die Einführung eines neuen Multi-Tag Antikollisionsprotokolls, das auf der Modulation der Notchposition (engl. Notch Position Modulation, NPM) und Tabellen (engl. Look-Up-Table, LUT) zur Bestimmung der Netzwerk- und MAC- Layer des chiplosen RFID Systems basiert. Die erste Generation der vorgeschlagenen Protokolls (Gen-1) baut auf einer Zweiteilung des zur Verfügung stehenden Spektrums auf. Im unteren Frequenzbereich, als Präambel Bandbreite bezeichnet, wird jedem RFID Tag seine individuelle Frequenzverschiebung übermittelt und im zweiten Bereich, der sogenannten Frame Bandbreite, ist die Identifikationsnummer (ID) des RFID Tags hinterlegt. Mit dieser Anordnung lässt sich jegliche Interferenz zwischen den verschiedenen RFID Tags unterbinden, da sich die Antworten der RFID Tags nicht gegenseitig überlagern. Die zweite Generation dieses Protokolls bringt eine Verbesserung sowohl bei der Coding Kapazität als auch bei der Nutzung des zur Verfügung stehenden Frequenzspektrums. Dies wird dadurch erreicht, dass die ID des RFID in einer Tabelle im Lesegerät gespeichert wird. Die individuelle Frequenzverschiebung dient dabei als Adresse für die gespeicherten IDs. Dieser Schritt vereinfacht die Komplexität der Struktur des RFID Tags signifikant, während gleichzeitig die Erkennungswahrscheinlichkeit erhöht wird. Des Weiteren werden die Key Performance Indikatoren untersucht um die Leistungsfähigkeit der Protokolle zu beweisen. Beide Protokollversionen werden modelliert und in einer Umgebung mit 10 chiplosen RFID Tags simuliert, um die Randbedingungen für die Entwicklung der RFID Tags und des RFID Lesegerätes zu ermitteln. Außerdem wird eine neuartige Testumgebung für ein MultiTag Ultra Breitband (engl. ultra wideband UWB) RFID System unter realen Testbedingungen basierend auf einem Software Defined Radio (SDR) Ansatz entwickelt. In dieser Testumgebung werden sowohl die gesendeten Signal als auch Detektierungstechniken, Leerraum Kalibrierung zur Reduzierung der Streustrahlung und die Identifikationsprotokolle untersucht. Als zweiter Schwerpunkt dieser Arbeit werden neue Techniken zur Reduzierung der Systemlaufzeit (engl. System Latency) eingeführt. Das Ziel dabei ist, die Zeit, die das RFID Lesegerät zum Erkennen aller in Lesereichweite befindlichen chiplosen FC RFID Tags braucht, zu verkürzen. Der Großteil der Systemlaufzeit wird durch das gewählte Frequenzscanverfahren, durch die Anzahl der Mittelungen zur Eliminierung der umgebenden Streustrahlung und durch die Dauer eines Frequenzsprungs bestimmt. In dieser werden dazu ein adaptives Frequenzsprungverfahren (engl. adaptive frequency hopping, AFH) sowie ein Verfahren Mittels adaptiver gleitender Fensterung (engl. adaptive sliding window, ASW) eingeführt. Das ASW Verfahren ist dabei im Hinblick auf die Identifizierung der RFID Tags nach dem Gen-1 Protokoll entwickelt, da es ein gleitendes Fenster zur Detektierung der Notches mit einer variablen Breite zum Auslesen der ID erfordert. Im Gegensatz dazu wird das Auffinden der im Gen-2 Protokoll verwendeten Notchpattern durch das AFH Verfahren verbessert. Dies wird über variable Frequenzsprünge, die auf die jeweiligen Notchpattern optimiert werden, erreicht. Beide Verfahren haben sich als effektiv sowohl im Hinblick auf die Systemlaufzeit als auch auf die Genauigkeit erwiesen. Das ASW und das AFH Verfahren wurden dazu in der oben erwähnten Testumgebung implementiert und mit dem klassischen Frequenzsprungverfahren, feste feingraduierte Frequenzschritte, verglichen. Die Experimente haben gezeigt, dass das vorgeschlagene AFH Verfahren in Kombination mit ASW zu einer beachtlichen Reduzierung der Systemlaufzeit von 58% führen. Das Ziel des dritten Schwerpunkts dieser Arbeit ist die Einführung einer neuartigen Technik zur Erhöhung der Informationsdichte (engl. Coding capacity) in einem chiplosen FC RFID Systems. Die hierfür vorgeschlagene Modulation der Notchbreite (engl. notch width modulation, NWM) ermöglicht die Kodierung von 4 Bits (16 Zuständen) pro Resonator in dem die Notchbreite und die dazugehörige Frequenzlage ausgenutzt werden. Für jeden Notch werden 150MHz Bandbreite reserviert, innerhalb derer das Codebit durch eine bestimmte Bandbreiten an unterschiedlichen Frequenzen bestimmt wird Cj ( fk,Bl). Das bedeutet, bei einer Arbeitsfrequenz im Bereich von 2–5 GHz können so 80 Bits realisiert werden. Des Weiteren wurde eine smarte Singulärwertzerlegung (engl. smart singular value decomposition, SSVD) Technik entwickelt, um die Notchbreite zu ermitteln und eine geringe Fehlerwahrscheinlichkeit zu garantieren. Die Nutzung von Blockcodes zur Behebung von Fehlern wurde untersucht, um den größtmöglichen Nutzen aus der so gewonnene Bittiefe zu erzielen. Als Folge konnte eine große Bittiefe mit einer hohen Lesegenauigkeit bei vereinfachtem Aufbau des Lesegeräts erzielt werden. Außerdem wurde eine neuartige RFID Tag Struktur entworfen, die bei einer Größe von 4× 5 cm2 eine Codedichte von 4 Bits/cm2 erreicht. Verschiedene RFID Tag Konfigurationen wurden erstellt und das neu eingeführte Codierungsverfahren mit Hilfe von elektromagnetischen (EM) Simulation und der bereits erwähnten Testplattform überprüft. Die erzielten Ergebnisse ermöglichen ein widerstandsfähiges RFID System in einer realen Umgebung. Alle vorgeschlagenen Beiträge sind durch analytische Modelle, Simulationen und Messungen auf mögliche Probleme und die Grenzen einer Realisierung unter realistischen Bedingungen geprüft worden.Chipless Radio Frequency IDentification (RFID) is a promising technology predicted to replace the optical barcode in the near future. This is due to several problematic issues i) the barcode cannot read Non-Line-Of-Sight (NLOS) tags; ii) each barcode needs human assistance to be read; iii) it is impossible to identify multiple tags at the same time; and iv) the considerable time delay in case of massive queues because different types of objects need to be serially scanned. The contributions included in this dissertation concentrate on three main aspects of the Frequency Coded (FC) chipless RFID system. The first one is the multi-tag identification, which deals with the existence of multiple tags in the reader’s interrogation region. The second aspect is the system latency that describes the time the reader needs to identify the tags. Finally, there is the coding capacity that is responsible for designing a chipless tag with larger information bits. The aim of these aspects is to realize a chipless RFID system. Since the chipless tags are memoryless as they do not include Integrated Circuits (ICs), the number of bits to be stored in the chipless tag is limited. Consequently, the current RFID standards and protocols designed for the chipped RFID systems are not applicable to the chipless systems. The main objective of the first contribution is to introduce novel multi-tag anti-collision protocols based on Notch Position Modulation (NPM) and Look-Up-Table (LUT) schemes determining the network and MAC layers of the chipless RFID systems. The first generation of the proposed protocol (Gen-1) relies on dividing the spectrum into two parts; the first one is the preamble bandwidth that includes a unique frequency shift for each tag. The second part is the frame bandwidth which represents the tag ID. The tag ID is obtained based on the predefined frequency positions, making use of the unique frequency shift. Consequently, the interference is avoided as there will not be any overlap between the tags’ responses. The second generation of the protocol (Gen-2) introduces an improvement in the spectrum utilization and coding capacity. This is realized by transferring the tag-ID to be stored in a table in the main memory of the reader (look-up-table). The unique shift of each tag represents the address of the tag’s ID. Therefore, the complexity of the tag structure will be significantly reduced with an enhanced probability of detection. Furthermore, the key performance indicators for the chipless RFID system are explored to validate the protocol’s performance. Both protocols are modeled and simulated to identify 10-chipless tags in order to set the regulations of the tag and reader design. Moreover, a novel real-world testbed for a multi-tag Ultra Wideband (UWB) chipless RFID system based on Software Defined Radio (SDR) is introduced. In this testbed, all the signaling schemes related to the transmitted signal, the detection techniques, the empty room calibration for the clutter removal process, and the identification protocols are applied. The aim of the second aspect is to introduce novel techniques that reduce the time required by the reader to identify the FC chipless RFID tags existent in the reader’s interrogation region. This time delay is called system latency. The main parameters that significantly affect the overall system latency are the frequency scanning methodology, the number of spectrum scanning iterations for the clutter removal process, and the hop duration. Therefore, the Adaptive Frequency Hopping (AFH) and the Adaptive Sliding Window (ASW) methodologies are proposed to meet the requirements of the FC chipless RFID tags. Regarding the ASW technique, it is suitable to identify the tags using the Gen-1 protocol which utilizes a sliding window (for detecting the notch) with an adaptive size to extract the tag’s-ID. The second adaptive methodology, AFH, can identify the tags with the Gen-2 protocol by using a variable frequency step that fits the corresponding notch patterns. These techniques are proven to be efficient for the chipless RFID systems with regard to latency and accuracy. Likewise, the designed AFH and ASW technique’s performance is compared to the classical Fixed Frequency Hopping (FFH) methodology with a fine frequency step to validate the accuracy of the proposed techniques. A real-world SDR based testbed is designed and the proposed adaptive algorithms as well as the classical FFH methodology are implemented. The experiments show that the proposed AFH combined with the ASW algorithms significantly reduce the system latency by 58%. The goal of the third aspect is to introduce a novel technique that increases the coding capacity of the FC chipless RFID system. The proposed Notch Width Modulation (NWM) scheme encodes 4 bits (16-combinations) per single resonator exploiting the notch bandwidth and its corresponding frequency position. Furthermore, each notch can reserve a window with a bandwidth of 150 MHz and inside this window the notch can obtain a certain bandwidth with a specific resonant frequency constructing the coding pairs Cj ( fk,Bl). Hence, 80-bits could be achieved at the operating frequency 2–5 GHz, preserving the operating frequency bandwidth. Also, a Smart Singular Value Decomposition (SSVD) technique is designed to estimate the notch bandwidth and to ensure a low probability of error. In addition, the utilization of a linear block code as an error correcting code is explored to make the best use of the obtained coding gain. Consequently, a high encoding efficiency and an accurate detection can be achieved in addition to a simplified reader design. Moreover, a novel 4× 5 cm2 tag structure is designed to meet the requirements of the NWM coding technique achieving a coding density of 4 bits/cm2. Different tag configurations are manufactured and validated by measurements using the SDR platform. The introduced coding methodology is conclusively validated using Electromagnetic (EM) simulations and real-world testbed measurements. The considered achievements for the proposed aspects offer a robust chipless RFID system that can be considered in real scenarios. Furthermore, all the proposed contributions are validated using analytical modeling, simulation and measurements in order to list their difficulties and limitations

Intelligent Sensor Networks

In the last decade, wireless or wired sensor networks have attracted much attention. However, most designs target general sensor network issues including protocol stack (routing, MAC, etc.) and security issues. This book focuses on the close integration of sensing, networking, and smart signal processing via machine learning. Based on their world-class research, the authors present the fundamentals of intelligent sensor networks. They cover sensing and sampling, distributed signal processing, and intelligent signal learning. In addition, they present cutting-edge research results from leading experts