Iterative decoding of joint data, time varying unknown symbol timing duration and phase tracking for wireless sensor networks and RFID systems

As increasing research effort has been made, pervasive computing is on the step closer to realization. Recent technologies have allowed smaller-scale computational devices with characteristics such as low-cost production, low energy consumption and wireless communication to capture and manage information. The technologies of Wireless Sensor Networks (WSN) and Radio Frequency Identification (RFID) are gaining high attention for their promising applications in the field of pervasive computing. Integrating RFID and WSN has been researched extensively in recent years, and deployed in variety of applications. In this paper, WSN architecture, sensor node hardware and RFID system are discussed firstly. According to RFID and WSN architectures and taking into account the specific circumstances of pervasive computing, the integrations of RFID and WSN are classified into three main categories. Each category of integration is described in details through some prototypes.

In this paper, we focus on configuring a low cost RFID (Radio Frequency IDentification) system with less RFID readers and low density RFID tag textiles for stable and accurate self-localization for an omni-directional mobile robot. An RFID system using multiple RFID readers and high density RFID tags has already been applied to an indoor mobile robot self-localization. However, the system production cost is relatively high. To reduce the production cost of the system while maintaining the self-localization performance, we redesign two new RFID systems configured with 20 RFID readers and 5 RFID readers enlarging the size of an RFID reader antenna. Particularly, a new likelihood function of the tag detection with the redesigned large size RFID reader antenna is proposed for Monte Carlo Localization (MCL). Furthermore, we come up with a novel arrangement of RFID tags installed in a hexagon pattern. The new arrangement of ID tags enables both low cost ID tag installation and high performance of self-localization. We examine the performances of robot self-localization with less RFID readers and lower density RFID tags installed on the floor based on MCL(Monte Carlo localization). The simulation demonstrates the validity of our proposed configuration of the RFID based self-localization.

최근 RFID (Radio Frequency Identification) 기술이 다양한 분야에서 관심을 받고 사용됨으로써 RFID 리더 제조회사들은 다양한 종류의 리더를 생산하고 있다. 현재 RFID 기술에서 RFID 태그 데이터 전송 형태는 EPCglobal에서 제공하는 표준 규약을 따르고 있지만 각 리더 별 리더 연결 및 통신 방법은 회사별로 다른 실정이다. RFID 리더를 사용하던 중 타 회사나 리더 인터페이스가 다른 RFID 리더로 변경하거나 새롭게 추가해야 하는 경우에는 사용자가 직접 RFID 미들웨어 개발단계로 돌아가 미들웨어의 내부 요소를 변경해야 하는 상황이 발생한다. 본 논문에서는 RFID 기술을 사용 시, 특히 여러 회사 또는 표준화되지 않은 인터페이스를 제공하는 RFID 리더를 사용하는 경우에 RFID 애플리케이션과 독립적으로 리더를 관리할 수 있는 리더 프레임워크를 개발하고자 한다. 본 리더 프레임워크는 RFID 애플리케이션과 RFID 리더 사이에 존재하여 RFID 리더 투명성을 제공한다. 본 리더 프레임워크는 현재 작동되고 있는 리더를 모니터링 할 수 있고, 리더의 속성을 확인할 수 있으며 RFID 태그 이벤트 정보, 시스템 로그 정보를 확인할 수 있다. 본 리더 프레임워크를 통해 수십 대의 이기종의 RFID 리더 상태를 용이하게 관리할 수 있게되며 애플리케이션 상의 코드 수정 없이 리더의 추가, 삭제가 가능하게 된다. More recently, variety RFID (Radio Frequency Identification) readers are produced by RFID equipment manufactures. Although a transmission standard instituted by EPCglobal is proposed for data transmission between the RFID readers and tags, other RFID reader protocols and the communication connection methods are be in use in other RFID companies. To replace or add the RFID readers of an RFID system, the developers should make changes to the core of the application and/or middleware. In this paper, we propose an RFID reader framework which can manage RFID readers without having to make changes the code of the application in environment with the growing number of heterogeneous RFID readers.This framework that sits on the layer between the RFID readers and the applications provides transparency to the RFID readers. Additionally, it can be used for monitoring the state and the property of all connected RFID, and for recording the RFID tag event logs and system logs. By using this framework, heterogeneous readers can be replaced and added without writing additional code in the applications. Consequently the readers can be easily managed and controlled by the RFID system administrator.

Radio Frequency IDentification (RFID) technology successfully integrates radio transmitter and receiver, small size memory space and control circuitry to remotely store and retrieve data via wireless RF transceiver. As low-cost RFID tag can be massively manufactured by semiconductor industry, new applications associated with RFID technology have emerged rapidly such as inventory tracking, book storage and management, and airport baggage handling. Generally an RFID system is composed of many RFID tags (or tagged objects), at least one RFID reader, and one backend application system with database. An RFID tag gains its operation energy from query signals that are radio waves transmitted by RFID reader. Once a tag responds the query with its stored information to RFID reader, usually a unique identity number or string, the RFID system can recognize the tag carrier and perform required business logic operation. As RFID technique is widely used in supply chain management, the corresponding RFID application systems are expected to process and manage large amount of tagged objects at a predefined period of time regularly. Therefore, for large-scaled RFID applications, tag reading throughput is very critical since it will affect the total data processing time. To measure tag reading throughput of a RFID system, two performance criteria are usually adopted: tag reading delay and reader energy consumption [5]. As RFID reader and tag always communicate over a shared wireless channel, it is very easy to have signal collisions during a normal tag identification process when multiple tags exist in reader’s interrogation area. Signal collision results in query or data retransmission and eventually increases communication overhead and time delay of tag identification. Hence, an efficient tag collision arbitration mechanism is very important and critical for RFID systems to achieve effective performance. Existing RFID tag identification schemes can be classified into aloha-based solutions [3, 10, 12-13, 16, 21, 23-24] and tree-based solutions [1, 2, 4, 6-9, 14-15, 17-20, 22]. In aloha-based schemes, a reader estimates the number of tags in its interrogation area and broadcasts the total number of timeslots to each tag. Then each RFID tag randomly selects its own timeslot to transmit its ID without knowing which timeslots have been selected by other tags. By distributing tag responses to distinct timeslots instead of getting all tag responses at the same time, aloha-based schemes effectively reduce the probability of signal collision. However, aloha-based schemes have tag starvation problem in which certain tags may not

Radio frequency identification (RFID) and wireless sensor networks (WSNs) have been popular in the industrial field, and both have undergone dramatic development. RFID and WSNs are well known for their abilities in identity identification and data transmission, respectively, and hence widely used in applications for environmental and health monitoring. Though the integration of a sensor and an RFID tag was proposed to gather both RFID tag and sensed information, few previous research efforts explore the integration of data transmission modes in the RFID and WSN systems to enhance the performance of the applications. In this paper, we propose a hybrid RFID and WSN system (HRW) that synergistically integrates the traditional RFID system and WSN system for efficient data collection. HRW has hybrid smart nodes that combine the function of RFID tags, the reduced function of RFID readers, and wireless sensors. Therefore, nodes can read each other's sensed data in tags, and all data can be quickly transmitted to an RFID reader through the node that first reaches it. The RFID readers transmit the collected data to the back-end servers for data processing and management. We also propose methods to improve data transmission efficiency and to protect data privacy and avoid malicious data selective forwarding in data transmission. Comprehensive simulation and trace-driven experimental results show the high performance of HRW in terms of the cost of deployment, transmission delay and capability, and tag capacity requirement.

Radio frequency identification (RFID) operates in different frequency bands (e.g., 125 kHz, 13.56 MHz, 868/915 MHz, 2.45 GHz and 5.8 GHz). Nowadays, indoor environment communications at frequency range 2.45 GHz have Bluetooth (IEEE 802.15.1) of wireless personal area networks (WPANs) and RFID systems working altogether which occur interference signals mainly by IEEE 802.15.1 of WPANs. This paper analyzes about interference effect from IEEE 802.15.1 to performance of RFID system at 2.45 GHz. From our study, it indicates that IEEE 802.15.1 interference can cause a significant increase in the bit error rate (BER) and the radio propagation loss of RFID system.

Every year researchers and engineers are finding new and useful applications for Radio Frequency Identification (RFID) systems (Finkenzeller, 2003). Because of the growing use of RFID systems, many different areas of research have also been developed to improve the performance of such systems. A few of these areas of research include novel antenna designs (Rao et at., 2005; Calabrese & Marrocco, 2008; Amin et al. 2009), analysis on the backscatter properties of RFID tags (Yen et al., 2007; Feng et al., 2006), mutual coupling between RFID tags (Li et al., 2008; Owen et al., 2009) and the deployment of RFID systems to complex and extreme environments (Qing & Chen, 2007; Sanford, 2008). There are many aspects to each area of research in RFID. A major topic in many of these areas involves research on the antenna design for RFID tags. This chapter will focus on the design of efficient space-filling antennas for passive UHF RFID tags. First, an introduction to RFID systems is presented. This is done by describing the major components in a RFID system and how they communicate. Then, the particular backscattering properties of a passive tag are described from a unique electric field integral equation standpoint and from an overall systems perspective (i.e., using the Friis transmission equation). This discussion will then be followed by a section describing a practical design process of various space-filling antennas for passive tags. Finally, a summary of future work and a conclusion about the chapter is presented.

Private companies and government have decided to provide Radio Frequency Identification (RFID) systems in places of free access to the population. However, as a result of such exposition, these systems become vulnerable to Denial of Service (DoS) attacks that can cause unavailability in the services. Furthermore, another complicating factor in that context regards the equipment or devices used on RFID systems, since they operate in frequency bands reserved for secondary communication systems, and consequently they have too few computational resources to deal with malicious electromagnetic interferences. Therefore, in this paper an Intrusion Detection System (IDS) is proposed to identify the occurrence of the malicious behavior and to notify the system operator about one specific type of electromagnetic interference in RFID systems - the Jamming attack. The obtained results of the system show the jamming attacks are detected prior of having a significant impact on the communication between the RFID reader and the tag - i.e., the jamming attack was detected even with insufficient power to impact on communication.

Remote technologies are changing our way of life. The radio frequency identification (RFID) system is a new technology which uses the open air to transmit information. This information transmission needs to be protected to provide user safety and privacy. Business will look for a system that has fraud resilience to prevent the misuse of information to take dishonest advantage. The business and the user need to be assured that the transmitted information has no content which is capable of undertaking malicious activities. Public awareness of RFID security will help users and organizations to understand the need for security protection. Publishing a security guideline from the regulating body and monitoring implementation of that guideline in RFID systems will ensure that businesses and users are protected. This chapter explains the importance of security in a RFID system and will outline the protective measures. It also points out the research direction of RFID systems.

The implementation of radio frequency identification (RFID) in the manufacturing industries specifically the production lines has enabled the creation of fully automated monitoring and tracking system. An investigation on the effects of various speeds and placements of product on a conveyor using statistical analysis is introduced in this paper. The experiment was conducted at the Auto-ID Laboratory (AIDL) at USM by setting up the RFID system on a conveyor set to determine whether the various speeds and placements of an RFID tag that was attached on the products would affect the performance of the proposed RFID system. The Design of Experiments (DOE) method known as two-factor factorial design was performed to find out the factors that influenced readability of an RFID tag detection. The Minitab statistical software was used to analyse the experimental results using interaction plots and two-way analysis of variance (ANOVA) procedure. The two factors investigated were conveyor speed at three different levels 0.1143 m/s, 0.1476 m/s and 0.179 m/s and orientation of the RFID-tagged product on the conveyor set for six different orientations. The statistical analysis showed that conveyor speed had no significant effect on the RFID system as its P-value was 0.369 which was greater than 0.05 level of significance. Product orientation had a significant effect with a P-value of close to 0.00. Therefore the orientation of an RFID-tagged product plays an important role in an RFID system. The best orientation to place the RFID-tagged product on a conveyor is by having its RFID tag directly facing an antenna. The latter was determined by looking at the mean tag detection percentage for the six orientations. The highest percentage of 95% was obtained when the tag directly faced the antenna.

There are many protocols proposed for protecting Radio Frequency Identification (RFID) system privacy and security. A number of these protocols are designed for protecting long-term security of RFID system using symmetric key or public key cryptosystem. Others are designed for protecting user anonymity and privacy. In practice, the use of RFID technology often has a short lifespan, such as commodity check out, supply chain management and so on. Furthermore, we know that designing a long-term security architecture to protect the security and privacy of RFID tags information requires a thorough consideration from many different aspects. However, any security enhancement on RFID technology will jack up its cost which may be detrimental to its widespread deployment. Due to the severe constraints of RFID tag resources (e.g., power source, computing power, communication bandwidth) and open air communication nature of RFID usage, it is a great challenge to secure a typical RFID system. For example, computational heavy public key and symmetric key cryptography algorithms (e.g., RSA and AES) may not be suitable or over-killed to protect RFID security or privacy. These factors motivate us to research an efficient and cost effective solution for RFID security and privacy protection. In this paper, we propose a new effective generic binary tree based key agreement protocol (called BKAP) and its variations, and show how it can be applied to secure the low cost and resource constraint RFID system. This BKAP is not a general purpose key agreement protocol rather it is a special purpose protocol to protect privacy, un-traceability and anonymity in a single RFID closed system domain.

The RFID (Radio Frequency IDentification) system is paid attention to as a new identification source that achieves a ubiquitous environment. Each RFID tag has the unique ID, and is attached to some object. A user reads the unique ID of a RFID tag with RFID readers and obtains the information on the object. One of the most important technologies that use the RFID system is the position estimation of RFID tags. The position estimation means to estimates the location of the object with the RFID tag. It can be very useful to acquire the location information of RFID tag. If a user can understand the position of the RFID tag, the position estimation can be applied to a navigation system for walkers. In this paper, we propose a new method named as Swift Communication Range Recognition (S-CRR) method as an extended improvement of the previous CRR method on the estimation delay. In this method, the position of RFID tag is estimated by selecting the communication area model which corresponds to those boundary angles. We carry out the performance evaluation by the experiments of RFID system and show the effectiveness of S-CRR for position estimation.

Radio Frequency Identification (RFID) systems consist of Electric Tags, or transponders and RF tag readers, or transceivers. Auto-tags of the RFID system have the unique ID feature and are capable of carrying information, which adds the tags more capability of which could be read only or read/write. RFID systems are now being used by more and more organizations connected with management, tracing, and control. The purpose of this study was to develop a information protection system (named PC-guard) using systems engineering and RFID technology. The login verification code can be notified in advance by using the PC-guard system because every PC user having their own Auto-tag will be checked with PC RFID reader. The information in the PC will be protected with RFID and the vibration sensor as the PC be turned on and be invaded. The development of this system using Blanchard and Fabrycky's procedure intends to bring the advantages of time saving and reduced risk using RFID technology. The developmental test and evaluation in the RFID lab had been done. The test results show that the PC-guard system can be operated well to protect the information in the PC with an active RFID tag and a PLC procedure with vibration sensor.

Radio Frequency IDentification (RFID) systems have rich applications in daily life. A crucial problem in RFID systems is to estimate the cardinality of RFID tags. Most exiting probabilistic RFID cardinality estimation algorithms utilize a certain pattern hidden in the response vector formed by the tag responses to make estimators. In this paper, we argue that finding the patterns is actually not necessary! In this paper, we present a novel approach to RFID cardinality estimation by making the full use of the whole response vector. We characterize the critical relationship between the number of RFID tags and the specific distribution of the bits in the response vector. In this paper, we consider two kinds of responses, i.e., empty / non-empty responses and empty / singleton / collision responses. To cater for RFID systems with a very large number of tags, we also generalize our estimation approach to handle geometrically distributed response vectors. Both rigid theoretical analysis and extensive simulations have been conducted and the conclusive results demonstrate that our approach is more accurate than existing state-of-the-art RFID estimation approaches.

Collision is a familiar problem in a RFID (radio frequency identification) system. How to solve this problem effectively is very important to the whole RFID system. A RFID system is always made up of two indispensable components: one is the tag, the other is the reader. Collisions occur when there are so many tags within the interrogation zone of a reader communicating with the reader synchronously. Binary search algorithm is an important anti-collision algorithm to solve the collision problems. But the main disadvantage of any existing algorithm based on binary search algorithm is the rate of identifying the identification codes (IDs) of tags is slow. In this paper, an improved anti-collision algorithm is proposed. Using this algorithm will recognize more tags in less time compared with other existing algorithms