From M-ary Query to Bit Query: a new strategy for efficient large-scale RFID identification

The tag collision avoidance has been viewed as one of the most important research problems in RFID communications and bit tracking technology has been widely embedded in query tree (QT) based algorithms to tackle such challenge. Existing solutions show further opportunity to greatly improve the reading performance because collision queries and empty queries are not fully explored. In this paper, a bit query (BQ) strategy based Mary query tree protocol (BQMT) is presented, which can not only eliminate idle queries but also separate collided tags into many small subsets and make full use of the collided bits. To further optimize the reading performance, a modified dual prefixes matching (MDPM) mechanism is presented to allow multiple tags to respond in the same slot and thus significantly reduce the number of queries. Theoretical analysis and simulations are supplemented to validate the effectiveness of the proposed BQMT and MDPM, which outperform the existing QT-based algorithms. Also, the BQMT and MDPM can be combined to BQMDPM to improve the reading performance in system efficiency, total identification time, communication complexity and average energy cost

From M-ary Query to Bit Query: a new strategy for efficient large-scale RFID identification

The tag collision avoidance has been viewed as one of the most important research problems in RFID communications and bit tracking technology has been widely embedded in query tree (QT) based algorithms to tackle such challenge. Existing solutions show further opportunity to greatly improve the reading performance because collision queries and empty queries are not fully explored. In this paper, a bit query (BQ) strategy based Mary query tree protocol (BQMT) is presented, which can not only eliminate idle queries but also separate collided tags into many small subsets and make full use of the collided bits. To further optimize the reading performance, a modified dual prefixes matching (MDPM) mechanism is presented to allow multiple tags to respond in the same slot and thus significantly reduce the number of queries. Theoretical analysis and simulations are supplemented to validate the effectiveness of the proposed BQMT and MDPM, which outperform the existing QT-based algorithms. Also, the BQMT and MDPM can be combined to BQMDPM to improve the reading performance in system efficiency, total identification time, communication complexity and average energy cost

Survey on Lightweight Primitives and Protocols for RFID in Wireless Sensor Networks

The use of radio frequency identification (RFID) technologies is becoming widespread in all kind of wireless network-based applications. As expected, applications based on sensor networks, ad-hoc or mobile ad hoc networks (MANETs) can be highly benefited from the adoption of RFID solutions. There is a strong need to employ lightweight cryptographic primitives for many security applications because of the tight cost and constrained resource requirement of sensor based networks. This paper mainly focuses on the security analysis of lightweight protocols and algorithms proposed for the security of RFID systems. A large number of research solutions have been proposed to implement lightweight cryptographic primitives and protocols in sensor and RFID integration based resource constraint networks. In this work, an overview of the currently discussed lightweight primitives and their attributes has been done. These primitives and protocols have been compared based on gate equivalents (GEs), power, technology, strengths, weaknesses and attacks. Further, an integration of primitives and protocols is compared with the possibilities of their applications in practical scenarios

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

Towards zero-power wireless machine-to-machine networks

This thesis aims at contributing to overcome two of the main challenges for the deployment of M2M networks in data collection scenarios for the Internet of Things: the management of massive numbers of end-devices that attempt to get access to the channel; and the need to extend the network lifetime. In order to solve these challenges, two complementary strategies are considered. Firstly, the thesis focuses on the design, analysis and performance evaluation of MAC protocols that can handle abrupt transitions in the traffic load and minimize the energy consumption devoted to communications. And secondly, the use of energy harvesting (EH) is considered in order to provide the network with unlimited lifetime. To this end, the second part of the thesis focuses on the design and analysis of EH-aware MAC protocols. While the Frame Slotted-ALOHA (FSA) protocol has been traditionally adopted in star topology networks for data collection, results show that FSA-based protocols lack of scalability and present synchronization problems as the network density increases. Indeed, the frame length of FSA must be adjusted to the number of contenders, which may be complex to attain in dense networks with large and dynamic number of end-devices. In order to overcome these issues, a tree splitting-based random access protocol, referred to as Low Power Contention Tree-based Access (LP-CTA), is proposed in the first part of this thesis. In LP-CTA, the frame length can be very short and fixed, which facilitates synchronization and provides better network scalability than FSA. While LP-CTA uses data slots for contention, it is possible to use short access requests in minislots, where collisions are resolved using tree splitting, and avoid the contention in data. Since these minislots can be much shorter than the duration of a data packet, the performance can be improved. The Low Power Distributed Queuing (LP-DQ) protocol proposed in this thesis is based on this idea. LP-DQ combines tree splitting with the logic of two distributed queues that manage the contention resolution and the collision-free data transmission. Results show that LP-DQ outperforms LP-CTA and FSA in terms of delay and energy efficiency, and it relaxes the need to know the size of the network and adapts smoothly to any change in the number of end-devices. The approach of LP-DQ is convenient when the messages transmitted by each end-device fit in one single slot, however, if the end-devices generate long messages that have to be fragmented, it is better to add a reservation mechanism in order to boost the performance. In this sense, the LPR-DQ protocol is proposed as an extension of LP-DQ where the concept of reservation is integrated to allow the end-devices reserve as many collision-free slots as needed. The second part of the thesis is devoted to the integration of the MAC layer with the use of energy harvesting. The variability and fluctuations of the harvested energy is considered for the design of EH-aware MAC protocols and three performance metrics are proposed: the probability of delivery, the data delivery ratio and the time efficiency. Previous works on data collection networks with EH focus on DFSA. In this thesis, the EH-CTA protocol is proposed as an adaptation of LP-CTA that takes the energy harvesting process into account. Results show that EH-CTA outperforms DFSA if the energy threshold for an end-device to become active is properly configured. In addition, while DFSA needs to adapt the frame length dynamically, EH-CTA uses a fixed frame length, thus facilitating scalability and synchronization. Finally, the EH-RDFSA and EH-DQ protocols are proposed for scenarios where data must be fragmented. EH-RDFSA is a combination of RFSA and DFSA, and EH-DQ is an extension of LPR-DQ.Esta tesis contribuye a resolver dos de los retos para el despliegue de redes M2M en escenarios de recolección de datos para el Internet de las Cosas: la gestión del acceso al canal de un número masivo de dispositivos; y la necesidad de extender la vida de la red. Para resolverlos se consideran dos estrategias complementarias. En primer lugar, se centra en el diseño, el análisis y la evaluación de protocolos MAC que pueden manejar transiciones abruptas de tráfico y reducen el consumo de energía. Y en segundo lugar, se considera el uso de mecanismos de captura de energía (Energy Harvesters, EH) para ofrecer un tiempo de vida ilimitado de la red. Con este fin, la segunda parte de la tesis se centra en el diseño y el análisis de protocolos MAC de tipo "EH-aware". Mientras que Frame Slotted-ALOHA (FSA) ha sido tradicionalmente adoptado en aplicaciones de recolección de datos, los resultados muestran que FSA presenta problemas de escalabilidad y sincronización cuando aumenta la densidad de la red. De hecho, la longitud de trama de FSA se debe ajustar según sea el número de dispositivos, lo cual puede ser difícil de estimar en redes con un número elevado y dinámico de dispositivos. Para superar estos problemas, en esta tesis se propone un protocolo de acceso aleatorio basado en "tree-splitting" denominado Low Power Contention Tree-based Access (LP-CTA). En LP-CTA, la longitud de trama puede ser corta y constante, lo cual facilita la sincronización y proporciona mejor escalabilidad. Mientras que LP-CTA utiliza paquetes de datos para la contienda, es posible utilizar solicitudes de acceso en mini-slots, donde las colisiones se resuelven utilizando "tree-splitting", y evitar la contención en los datos. Dado que estos mini-slots pueden ser mucho más cortos que la duración de un slot de datos, el rendimiento de LP-CTA puede ser mejorado. El protocolo Low Power Distributed Queuing (LP-DQ) propuesto en esta tesis se basa en esta idea. LP-DQ combina "tree-splitting" con la lógica de dos colas distribuidas que gestionan la resolución de la contienda en la solicitud de acceso y la transmisión de datos libre de colisiones. Los resultados demuestran que LP-DQ mejora LP-CTA y FSA en términos de retardo y eficiencia energética, LP-DQ no requiere conocer el tamaño de la red y se adapta sin problemas a cualquier cambio en el número de dispositivos. LP-DQ es conveniente cuando los mensajes transmitidos por cada dispositivo caben en un único slot de datos, sin embargo, si los dispositivos generan mensajes largos que requieren fragmentación, es mejor añadir un mecanismo de reserva para aumentar el rendimiento. En este sentido, el protocolo LPR-DQ se propone como una extensión de LP-DQ que incluye un mecanismo de reserva para permitir que cada dispositivo reserve el número de slots de datos según sea el número de fragmentos por mensaje. La segunda parte de la tesis está dedicada a la integración de la capa MAC con el uso de "Energy Harvesters". La variabilidad y las fluctuaciones de la energía capturada se consideran para el diseño de protocolos MAC de tipo "EH-aware" y se proponen tres métricas de rendimiento: la probabilidad de entrega, el "Data Delivery Ratio" y la eficiencia temporal. Los trabajos previos en redes de recolección de datos con EH se centran principalmente en DFSA. En esta tesis, el protocolo EH-CTA se propone como una adaptación de LP-CTA que tiene en cuenta el proceso de captura de energía. Los resultados muestran que EH-CTA supera DFSA si el umbral de energía para que un dispositivo se active está configurado correctamente. Además, mientras que en DFSA se necesita adaptar la longitud de trama de forma dinámica, EH-CTA utiliza una longitud de trama fija, facilitando así la escalabilidad y la sincronización. Por último, se proponen los protocolos EH-RDFSA y EH-DQ para escenarios en los que los datos deben ser fragmentados. EH-RDFSA es una combinación de RFSA y DFSA, y EH-DQ es una extensión de LPR-DQ.Aquesta tesi contribueix a resoldre dos dels reptes per al desplegament de xarxes M2M en escenaris de recol·lecció de dades per a l'Internet de les Coses: la gestió de l'accés al canal d'un nombre massiu de dispositius; i la necessitat d'extendre la vida de la xarxa. Per resoldre'ls es consideren dues estratègies complementàries. En primer lloc, es centra en el disseny, l'anàlisi i l'avaluació de protocols MAC que poden manegar transicions abruptes de trànsit i redueixen el consum d'energia. I en segon lloc, es considera l'ús de mecanismes de captura d'energia (Energy Harvesters, EH) per a oferir un temps de vida il·limitat de la xarxa. Amb aquesta finalitat, la segona part de la tesi es centra en el disseny i l'anàlisi de protocols MAC de tipus "EH-aware".Mentre que Frame Slotted-ALOHA (FSA) ha estat tradicionalment adoptat en aplicacions de recol·lecció de dades, els resultats mostren que FSA presenta problemes d'escalabilitat i sincronització quan augmenta la densitat de la xarxa. De fet, la longitud de trama de FSA s'ha d'ajustar segons sigui el nombre de dispositius, la qual cosa pot ser difícil d'estimar en xarxes amb un nombre elevat i dinàmic de dispositius. Per superar aquests problemes, en aquesta tesi es proposa un protocol d'accés aleatori basat en "tree-splitting" denominat Low Power Contention Tree-based Access (LP-CTA). En LP-CTA, la longitud de trama pot ser curta i constant, la qual cosa facilita la sincronització i proporciona millor escalabilitat.Mentre que LP-CTA utilitza paquets de dades per a la contenció, és possible utilitzar sol·licituds d'accés a mini-slots, on les col·lisions es resolen utilitzant "tree-splitting", i evitar la contenció a les dades. Atès que aquests mini-slots poden ser molt més curts que la durada d'un slot de dades, el rendiment de LP-CTA pot ser millorat. El protocol Low Power Distributed Queuing (LP-DQ) proposat en aquesta tesi es basa en aquesta idea. LP-DQ combina "tree-splitting" amb la lògica de dues cues distribuïdes que gestionen la resolució de la contenció en la sol·licitud d'accés i la transmissió de dades lliure de col·lisions. Els resultats demostren que LP-DQ millora LP-CTA i FSA en termes de retard i eficiència energètica, LP-DQ no requereix conèixer la mida de la xarxa i s'adapta sense problemes a qualsevol canvi en el nombre de dispositius.LP-DQ és convenient quan els missatges transmesos per cada dispositiu caben en un únic slot de dades, però, si els dispositius generen missatges llargs que requereixen fragmentació, és millor afegir un mecanisme de reserva per augmentar el rendiment. En aquest sentit, el protocol LPR-DQ es proposa com una extensió de LP-DQ que inclou un mecanisme de reserva per a permetre que cada dispositiu reservi el nombre de slots de dades segons sigui el nombre de fragments per missatge.La segona part de la tesi està dedicada a la integració de la capa MAC amb l'ús de "Energy Harvesters". La variabilitat i les fluctuacions de l'energia capturada es consideren per al disseny de protocols MAC de tipus "EH-aware" i es proposen tres mètriques de rendiment: la probabilitat d'entrega, el "Data Delivery Ratio" i l'eficiència temporal.Els treballs previs en xarxes de recol·lecció de dades amb EH se centren principalment en DFSA. En aquesta tesi, el protocol EH-CTA es proposa com una adaptació de LP-CTA que té en compte el procés de captura d'energia. Els resultats mostren que EH-CTA supera DFSA si el llindar d'energia perquè un dispositiu s'activi s'ajusta correctament. A més, mentre que a DFSA es necessita adaptar la longitud de trama de forma dinàmica, EH-CTA utilitza una longitud de trama fixa, facilitant així l'escalabilitat i la sincronització. Finalment, es proposen els protocols EH-RDFSA i EH-DQ per a escenaris en els quals les dades han de ser fragmentades. EH-RDFSA és una combinació de RFSA i DFSA, i EH-DQ és una extensió de LPR-DQ.Postprint (published version

Contention tree-based access for wireless machine-to-machine networks with energy harvesting

©2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.In this paper, we consider a wireless machine-to-machine network composed of end-devices with energy harvesters that periodically transmit data to a gateway. While energy harvesting allows for perpetual operation, the uncertain amount of harvested energy may not guarantee fully continuous operation due to temporary energy shortages. This fact needs to be addressed at the medium access control layer. We thus investigate the performance of an energy harvesting-aware contention tree-based access (EH-CTA) protocol, which uses a tree-splitting algorithm to resolve collisions and takes energy availability into account. We derive a theoretical model to compute the probability of delivery and the time efficiency. In addition, we conduct a performance comparison of EH-CTA using an EH-aware dynamic frame slotted-ALOHA (EH-DFSA) as a benchmark. We determine the parameters that maximize performance and analyze how it is influenced by the amount of harvested energy and the number of end-devices. Results reveal the superior performance of EH-CTA over EH-DFSA. While EH-DFSA requires an estimate of the number of contending end-devices per frame to adapt the frame length, EH-CTA uses short and fixed frame lengths, which enables scalability and facilitates synchronization as the network density increases.Peer ReviewedPostprint (author's final draft

COMPLEX PULSE FORMING TEACHNIQUE USING AM DETECTOR TYPE CIRCUITRY AND THE APPLICATION OF CDMA TO RFID FOR THE SIMULTANEOUS READING OF MULTIPLE TAGS

A novel complex ultra wideband RF pulse forming technique has been implemented in this research, using the coefficients derived from discrete Fourier transform of a virtual pulse train. Incorporated in this technique is a multiple frequency communication systems designed such that transmitter receiver proximity and the fading effect of the individual frequencies make part of a corresponding modulation technique. A code division multiple access (CDMA) application to RFID to greatly reduce read time, while at the same time eliminating inter tag interference, has been investigated with the analysis of a typical cart aisle scenario. With the current rate of growth of inventory world wide there is a tremendous need for more efficient method of data gathering, data storage, and data retrieval. In this dissertation, the application of the CDMA RFID technology has been analyzed to demonstrate the potentials of integrating the RFID technology to the EPC global numbering system

Modeling and simulation of an IoT enabled cold Chain Logistics management system

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Dünya ekonomisinin etkileyici bir şekilde büyümesi, soğuk zincirde izlenmesi ve yönetilmesi gereken özellikle sıcaklık duyarlı ürünler için belirsizlik durumları karşısında etkin, esnek ve duyarlı olabilmek amacıyla lojistik hizmetleri talep eden tedarik zincirinde artış sağlamıştır. Bunun gerçekleştirilebilmesi için Lojistik şirketerinin uygun bilişim teknolojileri ile desteklenmesi gerekmektedir. İnternet kullanımı ile müşteri ve lojistik sağlayıcı arasında etkili bir bilgi akışı ortamı sağlanmaktadır; ancak lojistik hizmetindeki bilgi ve ürün akışı arasındaki mevcut açıklık, sıcaklık duyarlı nesneler hakkında gerçek zamanlı bilginin elde edilmesinde karar vericiler için lojistik yönetimini daha zor duruma getiren bir problem oluşturmaktadır. Nesnelerin İnterneti alanındaki gelişmeler soğuk zincir sanayilerinde izleme, yönetme ve gerçek zamanlı görünürlük sağlama ve uygun zeka seviyesi ile bilgi paylaşımı alanında potensiyel çözümler sunmaktadır. Bu çalışmada soğuk zincirin gerçek zamanlı ortam sıcaklığını izleme, yönetme ve soğuk zincir içerisindeki sıcaklık duyarlı ürünlerin raf ömrünün tahmin edilmesi aracılığıyla tüm karar vericilerin karar desteklerini geliştirmeye yardımcı olan IoT erişimli soğuk zincir lojistiği gösterilemektedir. Çalışma içerisinde, gerçek zamanlı ortam verileri IEEE 802.15.4 kablosuz algılayıcı ağ yapısı kullanılarak elde edilmiş ve toplanan veriler bir ağ geçidi aracılığıyla sunucuya, ürünlerin raf ömürlerinin geliştirilen karar destek sistemi yardıyla tahmin edilebilmesini sağlamak üzere, gönderilmiştir. Ayrıca, soğuk zincir içerisindeki bozulabilir ürünlerin tespiti için Radyo Frekanslı Tanıma (Radio Frequency Identification-RFID) kullanılmıştır. Çalışma içerisinde kullanılan tüm cihazlar ve protokoller olay-güdümlü Riverbed Modeler yazılımıyla modellenerek benzetimleri yapılmıştır.The Dramatic growth of world economy results growth in the supply chain which demands logistics service to be agile, flexible and responsive in the face of uncertainty, especially for temperature sensitive products that need to be monitored and managed in the cold chain. To achieve this, Logistics companies must be supported by appropriate information technologies. Internet provides an effective means of driving information between customer and logistics provider, however, existing gap between products flow and information flow in logistic service has created a problem in getting real-time information about temperature sensitive items which make logistics management more challenging for decision makers. The growth of internet of things (IoT) gives a potential solution for monitoring, managing, and achieving real-time visibility and sharing information with the appropriate level of intelligence in cold chain industries. This paper demonstrates IoT enabled cold chain logistics that helps to enhance the decision support of all actors through managing, monitoring the real-time ambient temperature of the cold chain and predicting the shelf-life of temperature sensitive products inside the cold chain. In the study, real-time data of ambient parameters are gathered using IEEE 802.15.4 based wireless sensor networks and sent to the remote server through a gateway so that the shelf life of the products can be predicted by the decision support system developed. Radio Frequency Identification (RFID) is also used for identification of perishable goods inside the cold chain. All the devices and protocols employed in the study are modeled and simulated using event-driven Riverbed Modeler software

Capture-aware identification of mobile RFID tags with unreliable channels

Radio frequency identification (RFID) has been widely applied in large-scale applications such as logistics, merchandise and transportation. However, it is still a technical challenge to effectively estimate the number of tags in complex mobile environments. Most of existing tag identification protocols assume that readers and tags remain stationary throughout the whole identification process and ideal channel assumptions are typically considered between them. Hence, conventional algorithms may fail in mobile scenarios with unreliable channels. In this paper, we propose a novel RFID anti-collision algorithm for tag identification considering path loss. Based on a probabilistic identification model, we derive the collision, empty and success probabilities in a mobile RFID environment, which will be used to define the cardinality estimation method and the optimal frame length. Both simulation and experimental results of the proposed solution show noticeable performance improvement over the commercial solutions