RFID Systems: Research Trends and Challenges

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Copyright: RFID Systems: Research Trends and Challenges, Miodrag Bolic, David Simplot-Ryl, Ivan Stojmenovic, © 2010 John Wiley & Sons Ltd.


Chapter 1: Performance of Passive UHF RFID Systems in Practice
Authors: Miodrag Bolic, Akshay Athalye, and Tzu Hao Li

1.1 Introduction.
1.2 Ideal RFID System.
1.3 Practical RFID Systems.
1.4 Overview of the Book.
1.5 Conclusion.

Abstract: This chapter addresses issues and challenges in existing passive UHF RFID systems. The main focus is on low accuracy of reading. Other issues are considered including lack of defined reading zone; sensitivity of the system to orientation of the tag, deployed environment and type of the object the tag is attached to; and effect of multiple tags, multiple readers and mobility of tags and readers on reading accuracy. Some of the desired features are pointed out including security, localization, and ease of deployment.

Keywords: Ultra high frequency, passive RFID, read rate, reading accuracy


Chapter 2: Performance Metrics and Operational Parameters of RFID Systems
Authors: Raj Bridelall and Abhiman Hande

2.1 Overview.
2.2 Key Operational Parameters.
2.3 Classification of Commercially Available Products.
2.4 Conclusion.

Abstract: This chapter provides a cohesive overview of the key operational parameters that affect the performance of all types of RFID systems. Organized in a well structured taxonomical outline form, this chapter provides an excellent introduction to the fundamentals of RFID systems for students as well as professionals who are already experienced in the field but would appreciate a deeper understanding of technology. Combining contributions from leading academic and industry research, the authors provide a comprehensive overview of the theories leading to expected performance benefits such as low-cost, long distance tracking and real time positioning, as well as deficiencies currently experienced in the industry such as poor read rates and inadequate performance near liquids and metals.

Keywords: Active RFID, Semi-Passive, BAP, Passive RFID, Micro-Wireless, Dot, Energy Harvesting, Near-Field, Far-Field, RTLS, Triangulation, Trilateration, Multi-path, EIRP, ERP

Chapter 3: UHF RFID Antennas
Author: Daniel Deavours

3.1 Dipoles and Relatives.
3.2 T-Match and Relatives.
3.3 Putting it Together: Building an RFID Tag.
3.4 The Environment.
3.5 Conclusions, Trends, and Challenges.

Abstract: This chapter gives an overview of the principles and recent advances in UHF RFID antenna design. This includes an overview of dipole operation and the T-match commonly used by by UHF RFID tags. We then introduce a circuit model for modeling and designing RFID tags. A section is devoted to the process of designing a realistic RFID tag with wideband performance. The chapter considers various environmental factors that affect RFID performance in the "real world." Finally, the chapter shows ways in which one can overcome the so-called "metal/water problem" by use of microstrip RFID tags.

Keywords: RFID, UHF antennas, dipole antennas, microstrip antennas, impedance matching

Chapter 4: RFID Tag Chip Design
Authors: Na Yan, Wenyi Che, Yuqing Yang, and Qiang Li

4.1 Tag Architecture Systems.
4.2 Memory in Standard CMOS Processes.
4.3 Baseband of RFID Tag.
4.4 RFID Tag Performance Optimization.
4.5 Conclusion.

Abstract: RFID tag chip design is presented in this chapter, including architecture, RF/analog frontend, baseband, and non-volatile memory design. The chapter begins with description of tag architecture. Next, high efficiency frontend design of tag chip is explained. This section includes rectifier, power (voltage) regulator, demodulator, clock extraction or generation, backscattering, power on reset, voltage (current) reference, random number generator, etc. Non-volatile memory design in standard CMOS process is presented in details. Next, baseband design subsection is described with the emphasis on the low power techniques, such as sub-threshold and adiabatic technologies, and design considerations, including how to select the clock rate of the baseband cirsuit. RFID tag performance is analyzed, and some possible future technologies for optimization of tag performance are mentioned.

Keywords: RFID, tag, chip design, non-volatile memory, low-power, low-cost.

Chapter 5: Design of Passive Tag RFID Readers
Author: Scott Chiu

5.1 Overview.
5.2 Basics of Passive RFID Operation.
5.3 Passive RFID Reader Designs.
5.4 Advanced Topics on RFID Reader Design.
5.5 Conclusion.

Abstract: This chapter provides an overview of passive RFID reader hardware design. The principle of RFID operation is first reviewed to familiarize the communication mechanism between a reader and a tag. The design challenges are then presented and followed by functional block level descriptions. To further the discussion to issues encountered in real application environments, the chapter concludes with reader design and analysis for dense reader operations.

Keywords: Passive RFID, RFID reader, RFID interrogator design

Chapter 6: RFID Middleware: Concepts and Architecture
Authors: Nathalie Mitton, Loic Schmidt, and David Simplot-Ryl

6.1 Introduction.
6.2 Overview of an RFID Middleware Architecture.
6.3 Readers Management.
6.4 Data Management and Application-Level Events.
6.5 Store and Share Data.
6.6 Example.
6.7 Conclusion.

Abstract: The RFID middleware is a set of components which aims to manage RFID readers, deals with RFID-events and data, and is connected to end-user applications. The middleware is located between readers and business applications. This chapter describes the general architecture of such a middleware. It starts with the management of readers that includes reader protocol/interface, monitoring, and settings. Next, data management is addressed. An RFID application can generate a huge amount of data which must be processed and stored intelligently in a database. The important point here is the data “filtering and collection” or how to transform a tag reading flow into some comprehensive “what, when and where” events thanks to the use of the application-level event engine (ALE). Next, we present how data are stored in the system and shared between multiple sites, multiple partners. The main components here are the EPC information service (EPCIS) and the object name server (ONS). The former adds some business information and store events coming from the ALE engine. The latter provides a mechanism to retrieve information about an object from its identification number.

Keywords: Radio Frequency IDentification, middleware, Electronic Product Code, EPCglobal, ALE, EPCIS, RP, LLRP, ONS


Chapter 7: Aloha-Based Protocols
Authors: Kwan-Wu Chin and Dheeraj Klair

7.1 Pure Aloha.
7.2 Slotted Aloha.
7.3 Framed Slotted Aloha.
7.4 Conclusion.

Abstract: In RFID systems, the primary aim of the reader is to identify tags quickly. Hence, anti-collision protocols play an important role in arbitrating tag replies such that a reader experiences minimal or no collisions in each read round. Moreover, they must minimize idle slots to ensure high system efficiency. Otherwise, a RFID reader will experience prolonged identification delays, and also energy and bandwidth wastage. Henceforth, this chapter presents a comprehensive review of Aloha based anti-collision protocols. Specifically, we will present Pure Aloha (PA), Slotted Aloha (SA), Framed Slotted Aloha (FSA), and their variants. In addition, we will analyze their read performance with increasing number of tags.

Keywords: Aloha, tag estimation function, Slotted Aloha, Framed Slotted Aloha

Chapter 8: Tree-Based Anti-Collision Protocols for RFID Tags
Author: Petar Popovski

8.1 Introduction.
8.2 Principles of Tree-Based Anti-Collision Protocols.
8.3 Tree Protocols in the Existing RFID Specifications.
8.4 Practical Issues and Transmission Errors.
8.5 Cooperative Readers and Generalized Arbitration Spaces.
8.6 Conclusion.

Abstract: An RFID system needs to be equipped with anti-collision protocol in order to arbitrate over tag collisions and enable the reader to gather a successful reply from each tag in its range. This chapter deals with an important class of anti-collision protocols, called tree protocols. Tree protocols are based on recursive solution and a query structure that forms a binary tree. This chapter introduces the engineering principles of tree protocols. We also introduce two practical tree protocols for RFID systems and related them to the describe principles. Furthermore, we discuss techniques that can be used to design tree protocols that can adapt to various practical requirements, such as transmission errors, tags that move in/out of reader range, etc. Finally, we introduce a framework that can be used to design tree protocols for scenarios with multiple cooperating readers.

Keywords: RFID, tree protocols, anti-collision protocols, collision resolution protocols, conflict resolution protocols, arbitration protocols, cooperative RFID readers

Chapter 9: A Comparison of TTF and RTF UHF RFID Protocols
Authors: Alwyn Hoffman, Johann Holm, and Henri-Jean Marais

9.1 Introduction.
9.2 Requirements for RFID Protocols.
9.3 Different Approaches Used in UHF Protocols.
9.4 Description of Stochastic TTF Protocols.
9.5 Comparison between ISO18000-6C and TTF Protocols.
9.6 Conclusion.

Abstract: Passive UHF RFID has gained much prominence in recent years, based on the promise it holds to enable the tracking of large numbers of items at low cost, both in supply chains as well as in transport systems. The performance of passive UHF RFID systems, as well as its compliance with frequency regulations, is largely impacted by the air-interface protocol employed to control the communications between readers and transponders. In this respect two opposing philosophies have been implemented with various degrees of success: the first based on control of the communications by the reader (so-called reader-talks-first or RTF protocols), and the other based on stochastic behavior of the transponders without interference from the reader (so-called tags-talk-first or TTF protocols). In this chapter the inherent benefits of the two approaches are described, as well as the way that recent technology developments have impacted upon practical implementations of the competing protocols. A comparison is drawn between the expected performances that could be attained using either of these approaches, against the background of typical target applications for passive UHF RFID.

Keywords: tags-talk-first, protocols


Chapter 10: Integrating RFID Readers in Enterprise IT
Authors: Christian Floerkemeier, Sanjay Sarma

10.1 Related Work.
10.2 RFID System Services.
10.3 Reader Capabilities.
10.4 RFID System Architecture Taxonomy.
10.5 EPCglobal Standards.
10.6 Adoption of High-Level Reader Protocols.
10.7 Potential Future Standardization Activities.
10.8 Conclusion.

Abstract: RFID system deployments require the configuration, monitoring and data management of RFID readers. This chapter provides an overview of different services deployed in intra-organizational RFID systems and analyzes system architectures implemented today. We also compare emerging standards developed by the EPCglobal community that aim to standardize system interfaces and reader protocols in RFID deployments. Our analysis distinguishes a centralized architecture, where a controller device or a software component on an application server locally controls the RFID readers, and an autonomous architecture, where the RFID readers execute application logic and are managed by enterprise IT management systems.

Keywords: RFID Middleware, Reader Protocols, LLRP, ALE, RP

Chapter 11: Reducing Interference in RFID Reader Networks
Authors: Sung Won Kim and Gyanendra Prasad Joshi

11.1 Introduction.
11.2 Interference Problem in RFID Reader Networks.
11.3 Access Mechanism, Regulations, Standards and Algorithms.
11.4 Comparison.
11.5 Conclusion.

Abstract: The utilization of RFID system is increased drastically due to its wide range of applications in various places. Multiple RFID readers try to access the same tag at the same time where readers are deployed densely, as a result of which the signals may interfere with each other. Reader interference problem (also called reader collision problem) is a bottleneck of overall system performance in a dense RFID system. Current standard cannot solve the reader interference problem completely. There are several reader anti-collision algorithms to mitigate the reader interference problem. In this chapter, we will discuss the reason of reader interference in RFID, standards and regulations, existing anti-collision algorithms, their classification and comparison. The contents of the chapter will be as follows: introduction, reader interference problem in RFID, standards and regulations, existing reader anti-collision algorithms, their classification and comparison in terms of throughput, conclusion, references, and questions.

Keywords: RFID Reader collision problem, RFID reader anti-collision algorithms, RFID MAC protocols

Chapter 12: Optimal Tag Coverage and Tag Report Elimination
Authors: Bogdan Carbunar, Murali Krishna Ramanathan, Mehmet Koyuturk, Suresh Jagannathan, and Ananth Grama

12.1 Introduction.
12.2 Overview of RFID Systems.
12.3 Tree Walking: An Algorithm for Detecting Tags in the Presence of Collisions. 12.4 Reader Collision Avoidance.
12.5 Coverage Redundancy in RFID Systems: Comparison with Sensor Networks. 12.6 Network Model.
12.7 Optimal Tag Coverage and Tag Reporting.
12.8 Redundant Reader Elimination Algorithms: A Centralized Heuristic.
12.9 RRE: A Distributed Solution.
12.10 Adapting to Topological Changes.
12.11 The Layered Elimination Optimization (LEO).
12.12 Related Work.
12.13 Conclusion.

Abstract: This chapter addresses two important tag detection problems occurring in RFID systems. The first problem, of optimally covering tags, consists of identifying a minimal set of readers that cover all tags present in the system. The second problem, of optimally reporting detected tags, consists of eliminating redundant tag reports generated by multiple readers. The optimal tag coverage problem is equivalent to the problem of determining the maximum number of redundant readers. A redundant reader can be safely turned off or removed from the network without affecting the number of tags covered. In this chapter, we first describe the coverage redundancy problem in wireless sensor networks and explain differences between this problem and the optimal tag coverage problem. Second, we study different techniques for solving the tag coverage and reporting problems. We show that the algorithms studied are adaptive to system changes, including new tag and reader deployments, as well as component leaves or failures.

Keywords: RFID reader collision avoidance, RFID coverage redundancy, optimal tag reporting

Chapter 13: Delay/Disruption-Tolerant Mobile RFID Networks: Challenges and Opportunities
Authors: Hongyi Wu and Zhipeng Yang

13.1 Motivation.
13.2 Overview of FINDERS.
13.3 General Feasibility Study.
13.4 Unique Challenges and Tactics.
13.5 Related Work.
13.6 Conclusion.

Abstract: This chapter centers on delay/disruption-tolerant mobile RFID (Radio Frequency IDentification) networks. In particular, we introduce a Featherlight Information Network with Delay-Endurable RFID Support (FINDERS), composed of passive RFID tags which are ultra light, durable, and flexible, without power supply for long-lasting applications under strict weight constraints and harsh environments. It expands the use of RFID gear for wireless network construction, aiming to find events of interest and gather aggregate information. In this chapter, we present an analytic model to show the feasibility of FINDERS and discuss the communication and networking challenges therein, due to its sporadic wireless links, unique asymmetric communication paradigm, intermittent computation capability, and extremely small memory of tags.

Keywords: Asymmetric Communication, Delay-Tolerant Network (DTN), Intermittent Computation, Radio Frequency IDentification (RFID).


Chapter 14: Improving Read Ranges and Read Rates for Passive RFID Systems
Authors: Zhiguang Fan, Fazhong Shen, Jianhua Shen, and Lixin Ran

14.1 Introduction.
14.2 Signal Descriptions and Formulations for Passive Backscatter RFID Systems. 14.3 Improving the Read Range of a Passive RFID System.
14.4 Improving the Read Rate of a Passive RFID System.
14.5 Two Design Examples for RFID System.
14.6 Conclusion.

Abstract: The read range and the read rate characterize the performance of RFID systems from different points of view. This chapter investigates the primary principle of passive RFID systems in far-field range. Signal descriptions and formulations of SNR and the read range are theoretically presented. Based on that, the read range and read rate issues are discussed further. Apart from the conclusions drawn directly from the formulations, other research efforts related to improving read rate and range are also introduced. At the end of this chapter, two examples illustrating cost-effective designs of long-range RFID readers utilizing off-the-shelf chips that were originally designed for cell phones are presented.

Keywords: RFID, read range, read rate

Chapter 15: Principles and Techniques of RFID Positioning
Authors: Yimin Zhang, Xin Li, and Moeness Amin

15.1 Introduction.
15.2 Tag Range Estimation Techniques.
15.3 DOA Estimation Techniques.
15.4 RFID Positioning Techniques.
15.5 Improving Positioning Accuracy.
15.6 Conclusion.

Abstract: This chapter provides a comprehensive introduction of RFID positioning technologies from both principle and technique perspectives. The majority of RFID positioning systems are based on the fusion of multiple pieces of relevant information, such as the range and the direction-of-arrival (DOA). For example, trilateration is a commonly used approach which determines the tag position by incorporating range information of an RFID tag estimated at three or more spatially separated readers or reader antennas. Range information can be obtained through received signal strength (RSS), round-trip time-of-flight (TOF), time-difference of arrival (TDOA), or phase difference-of-arrival (PDOA) of the RFID signals. By using directional antennas or multi-antenna array processing technology for the estimation of DOA information observed at multiple positions, tags can also be localized by utilizing the triangulation technique. Alternatively, RFID tag position can be determined through hybrid techniques that combine the range and DOA information. As a result, it is possible to locate the position of an RFID tag with a single reader that provides both range and DOA information. Other RFID tag positioning techniques include radio map matching that compares the signal signatures with that of reference tags with known position. In addition, the proximity method is a simple but less accurate positioning approach that uses spatially separated reader antennas and approximates the location of a tag by that of a reader antenna through which the tag can be read.

Keywords: Positioning, trilateration, triangulation, received signal strength, time-of-arrival, time-difference-of-arrival, time-of-flight, direction-of-arrival, radio map matching, proximity.

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Chapter 16: Towards Secure and Privacy-Enhanced RFID Systems
Authors: Heiko Knospe and Kerstin Lemke-Rust

16.1 Introduction.
16.2 Security and Privacy.
16.3 Classification of RFID Systems.
16.4 Attacks on RFID Systems and Appropriate Countermeasures.
16.5 Lightweight Cryptography for RFID.
16.6 Conclusion.

Abstract: A survey and taxonomy of state-of-the-art research related to the fundamentals of security and privacy of RFID systems is presented. Attacks against common RFID systems are described and evaluated, showing the need for additional security and privacy mechanisms. RFID systems are especially exposed to attacks on the radio interface such as eavesdropping, replay, relay, jamming, tracking, and hotlisting. Side-channel, physical implementation, and cryptanalytic attacks have emerged as major threats to RFID security. Based on current experiences and on ongoing research a summary of attacks and countermeasures is provided. Lightweight cryptography forms the basis for new frameworks with improved security and a summary of the relevant cryptographic primitives is given. Considerable progress has recently been achieved and secure symmetric encryption algorithms are feasible even for very restricted transponders. This forms a basis for enhanced security and privacy of future RFID systems and applications.

Keywords: RFID, Security, Privacy, Cryptanalytic Attacks, Physical Implementation Attacks, Lightweight Cryptography.

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Chapter 17: Cryptographic Approaches for Improving Security and Privacy Issues of RFID Systems
Authors: Miyako Ohkubo, Koutarou Suzuki, and Shingo Kinoshita

17.1 Introduction.
17.2 Threats against the RFID System.
17.3 Required Properties.
17.4 Cryptographic Protocols for Identification with Privacy.
17.5 Cryptographic Protocols for Authentication without Privacy.
17.6 Cryptographic Protocols for Privacy and Other Requirements.
17.7 Implementation.
17.8 Real Systems and Attacks.
17.9 Conclusion.

Abstract: We survey state-of-the-art research related to the security and privacy of RFID systems. Applications and systems based on RFID technology should satisfy requirements for preserving privacy and providing usability. We classify the security and privacy issues of RFID systems based on privacy issues, and moreover, authenticity, restriction and delegation of traceability, forward security and other requirements. Then, we survey cryptographic protocols for addressing solutions to these issues.

Keywords: Privacy, Security, Cryptography, Attack, Cryptographic Protocol.

Chapter 18: Novel RFID Technologies: Energy Harvesting for Self-Powered Autonomous RFID Systems
Authors: Raj Bridelall and Abhiman Hande

18.1 Introduction.
18.2 Novel Low Power Architectures.
18.3 Energy Harvesting Optimized for RFID.
18.4 Future Trends in Energy Harvesting.
18.5 Conclusion.

Abstract: This chapter examines energy harvesting (EH) for novel low power RFID based sensor architectures to enable self-powered autonomous RFID systems. Architectures such as Dual-Active and Micro-Wireless that rely on stored on-board energy to enable greater range, higher throughput, and more robust performance in electromagnetically unfriendly environments are covered. Various forms of EH technology are explored that supplement or fully replace batteries. The chapter introduces EH approaches suitable for low-power RFID with adaptations that also support wireless sensor network modalities. Various forms of EH transducers such as solar, vibration, and thermoelectric are explored for different applications. The chapter also covers hybrid approaches that optimally combine various forms of EH transducers to meet these new challenges in self-sufficient wireless sensors. Future trends that construct EH devices from thin film micro-electro-mechanical systems (MEMS) to enable high volume and low-cost roll-to-roll manufacturing techniques are highlighted.

Keywords: Piezoelectric, Electromagnetic, Vibration, Thermoelectric, Solar, MEMS, Energy Harvesting, Active RFID, Micro-Wireless, Remote Sensors, Wireless Sensor Networks, Power Management.

Chapter 19: Simulators and Emulators for Different Abstraction Layers of UHF RFID Systems
Authors: Christian Steger, Alex Janek, Reinhold Weiß, Vojtech Derbek, Manfred Jantscher, Josef Preishuber-Pfluegl, and Markus Pistauer

19.1 Introduction.
19.2 The Simulation/Emulation Platforms.
19.3 UHF RFID Simulation Platform.
19.4 Real-Time HIL-Verification and Emulation Platform.
19.5 Higher Class Tag Architecture Based on Energy Harvesting.
19.6 Conclusion.

Abstract: This chapter begins with an introduction to model-based design of UHF RFID systems followed by the basic concepts of conformance and interoperability testing. The following sections present the simulation/emulation methodologies. The modeling and simulation platform creates a hardware-software application wide model with the stress on high modularity. As a result, a simulation tool will be developed that could be used to optimize the application set up for evaluating the design of hardware components and system parts of UHF RFID systems. Finally, the design and verfication of an architecture of a RFID tag including energy harvesting devices is introduced.

Keywords: UHF RFID system, model-based development, HW/SW cosimulation, higher class tags architectures, energy harvesting/scavenging




Copyright: RFID Systems: Research Trends and Challenges, Miodrag Bolic, David Simplot-Ryl, Ivan Stojmenovic, © 2010 John Wiley & Sons Ltd.