1. RFID I System and Features

2. 2 Communication Technology Laboratory Wireless Communication Group Outline Introduction RFID Main Components Fundamental Operating Principles Multiple Access

3. 3 Communication Technology Laboratory Wireless Communication Group Introduction Radio Frequency Identification (RFID): automatic identification method for storing and/or retrieving data to/from an electronic device through radio frequency or magnetic field variations

4. 4 Communication Technology Laboratory Wireless Communication Group Introduction Technology

5. 5 Communication Technology Laboratory Wireless Communication Group Introduction Strengths and Weaknesses –Strengths of RFID technology Line-of-sight not required Multiple tags identification Long range identification feasible Can read/write to tags Operates in harsh environments Memory to store data Possibility to integrate sensors –Drawbacks Costs Unreliable under certain conditions

6. 6 Communication Technology Laboratory Wireless Communication Group Introduction Applications

7. 7 Communication Technology Laboratory Wireless Communication Group Introduction New field to investigate...ubiquitous world ?!

8. 8 Communication Technology Laboratory Wireless Communication Group Introduction Is RFID the right technology ? Hitachi produces the world's smallest RFID chip: mu-Chip 0.4 mm x 0.4 mm Powder RFID chips next to a human hair 0.05 mm x 0.05 mm Pictures taken from: http://nexusilluminati.blogspot.com/2011/05/rfid-powder-worlds-smallest-rfid-tag.html (under Creative Commons Copyright)http://nexusilluminati.blogspot.com/2011/05/rfid-powder-worlds-smallest-rfid-tag.html

9. 9 Communication Technology Laboratory Wireless Communication Group Introduction The Internet of Things (IoT) the term IoT have been coined by a member of the RFID development community around 2000 referred to the possibility of discovering information about a tagged object by browsing an Internet address or database entry that corresponds to a particular RFID. IoT today refers to the general idea of things, especially everyday objects, that are readable, recognizable, locatable, addressable, and/or controllable via the Internet—whether via RFID, wireless LAN, wide-area network, or other means. Source of figure: "Internet of Things" by Wilgengebroed on Flickr - Cropped and sign removed from Internet of things signed by the author.jpg. Licensed under Creative Commons Attribution 2.0 via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Internet_of_Things.jpg#mediaviewer/File:Internet_of_Things.jpg

10. 10 Communication Technology Laboratory Wireless Communication Group Introduction IoT enabling building blocks –Machine-to-machine interfaces and protocols of electronic communication –Microcontrollers –Wireless communication –RFID technology –Energy harvesting technologies –Sensors –Actuators –Location technology –Software Source: http://www.dni.gov/nic/PDF_GIF_confreports/disruptivetech/appendix_F.pdfhttp://www.dni.gov/nic/PDF_GIF_confreports/disruptivetech/appendix_F.pdf

11. 11 Communication Technology Laboratory Wireless Communication Group RFID Systems - main components For the most part, RFID systems comprise three principal components: –Reader(s) –Transponder or tag(s) –Host/Application/Middleware

12. 12 Communication Technology Laboratory Wireless Communication Group RFID Systems - main components

13. 13 Communication Technology Laboratory Wireless Communication Group RFID Systems – Frequency Bands LF MF HFVHFUHF 100K 1M 10M100M1G 10G Frequency (Hz) inductive radiative

14. 14 Communication Technology Laboratory Wireless Communication Group RFID Systems – Frequency Bands Frequency 125/134 KHz13.56 MHz860-960 MHz2.45 GHz Access Control Animal Tracking Often used for vehicle identification. Can be used globally without a license. Sometimes referred to as LowFID. Smart Cards Smart shelve tags for item level tracking Library Books Airline Baggage Maintenance data logging Electronic ticketing Contactless payment Access control Garment tracking Pallet tracking Carton Tracking Electronic toll collection Parking lot access EPC standard built around this frequency. This band cannot be accessed globally and there are significant restrictions on its use. When it is used, it is often used for asset management, container tracking, baggage tracking, etc. Airline Baggage Electronic toll collection Used for long range tracking and with active tags Typical Applications

15. 15 Communication Technology Laboratory Wireless Communication Group RFID Systems - Reader Reader –Different frequency ranges –Conform to different standards and protocols –Different types: proximity ( 1m) readers –Readers can be at fixed points (entrance/exit, point of sale,…) or can also be mobile (portable) –Different shapes and sizes –Main functions: Activate the tag and (passive tags) supply energy Structure the communication sequence with the tag Transfer data between the application software and a contactless data carrier Perform anti-collision procedure Authentication procedure – Price: 50…2000$

16. 16 Communication Technology Laboratory Wireless Communication Group RFID Systems - Reader –Block diagram

17. 17 Communication Technology Laboratory Wireless Communication Group RFID Systems - Reader –HF interface: inductive system

18. 18 Communication Technology Laboratory Wireless Communication Group RFID Systems - Reader –HF interface: microwave system

19. 19 Communication Technology Laboratory Wireless Communication Group RFID Systems - Reader –Examples

20. 20 Communication Technology Laboratory Wireless Communication Group RFID Systems - Tag Tag –Different operating frequencies –Different sizes and forms –It can be attached to almost everything pallets, vehicles, shirts, pets, luggage, electronic devices,… –Different capabilities –Different types: –Price: 0.05…200$

21. 21 Communication Technology Laboratory Wireless Communication Group RFID Systems - Tag –Block diagram HF interface: inductive tag

22. 22 Communication Technology Laboratory Wireless Communication Group Power Supply –A very important feature of RFID systems is the power supply to the transponder –Tags need energy for two reasons To power the internal microchip To transmit data to the reader –Categories of tags Passive tags –No internal battery –The energy transmitted by the reader (electrical/magnetic field) is used for both tasks Semi-active tags –Internal battery used for power the microchip –The energy from the reader is used for data transmission Active tags –Internal battery is used for both tasks RFID Systems - Tag

23. 23 Communication Technology Laboratory Wireless Communication Group RFID Systems - Tag Standards (Air interface Protocols) Tag Type: Frequency 125/134 KHz5-7 MHz13.56 MHz303/433 MHz860-960 MHz2.45 GHz PassiveISO 11784/5, 14223 ISO18000-2 HiTag ISO10536 iPico DF/iPX MIFARE ISO14443 Tag-IT ISO15693 ISO18000-3 TIRIS icode ISO18000- 6A,B,C EPC class 0 EPC class 1 Intellitag Title 21 AAR S918 Ucode ISO18000-4 Intellitag μ-chip Semi Passive AAR S918 Title 21 EZPass Intelleflex Maxim ISO18000-4 Alien BAP ActiveANSI 371.2 ISO18000-7 RFCode ISO18000-4 ANSI 371.1

24. 24 Communication Technology Laboratory Wireless Communication Group RFID Systems - Tag Freq.StandardsTitleYear LFISO 11784/5RFID of Animals- Technical Concepts1996 LFISO 14233RFID of Animals – Advanced Transponders2003 LFISO 18 000 Part 2 Type A/BParameters for Air Interface Communications below 135 kHz2004 HFISO 15 693Identification Cards – Vicinity Cards2001 HFISO 14443Type A/BIdentification Cards – Proximity Cards2001 HFISO 18 000 Part 3 Mode 1/2Parameters for Air Interface Communications at 13.56 MHz2004 HFEPCglobal Class 1 13.56 MHz ISM Band Class 1Radio Frequency Identification Tag Interface Specification2003 UHFISO 18 000 Part 6 Mode A/BParameters for Air Interface Communications at 860 to 930 MHz2004 UHFEPCglobal Class 0 (Gen. 1) 860 MHz-935 MHz Class 0 Radio Frequency Identification Tag Protocol Specification2003 UHFEPCglobal Class 1 (Gen. 1) 860 MHz-960 MHz Class 1 Radio Frequency Identification Tag Radio Frequency & Logical Communication Interface Specification 2002 UHFEPCglobal Class 1 (Gen. 2)UHF Class 1 Generation 2 Protocol2004 MWISO 18 000 Part 4Parameters for Air Interface Communications at 2.45 GHz2004 LF MF HFVHFUHF 100K 1M 10M100M1G 10G inductive radiative

25. 25 Communication Technology Laboratory Wireless Communication Group Information storage and processing RFID Systems - Tag EAS: Electronic Article Surveillance

26. 26 Communication Technology Laboratory Wireless Communication Group Data access –Read only tags Write once and read many times Communication with the reader is unidirectional, with the tag continuously sending its ID to the reader Data transmission from the reader to the tag is not possible Cheap, low power and fast read –Read-write tags ID plus additional read-write memory –Advanced memory structure and security features Crypto functions RFID Systems - Tag

27. 27 Communication Technology Laboratory Wireless Communication Group RFID Systems - Tag –Examples "Microchip rfid rice". Licensed under Public domain via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Microchip_rfid _rice.jpg#mediaviewer/File:Microchip_rfid_rice.jpg

28. 28 Communication Technology Laboratory Wireless Communication Group RFID Systems - Host/Application/Middleware Host/Application/Middleware –In applications like e.g. supply chain management and logistics, there is no longer a one-to-one relationship between the reader and the application –These applications need a middleware that manages large deployments of readers and the amount of data these readers capture –Middleware price: 5K…50K$

29. 29 Communication Technology Laboratory Wireless Communication Group RFID Systems - Host/Application/Middleware –Middleware functionalities

30. 30 Communication Technology Laboratory Wireless Communication Group Air Interface: coupling –The way the reader and the tag send/receive information or power –Coupling in the near field or the far field –The (magnetic) near field is an energy storage field It drops off ~ 1/r 3 –The electromagnetic far field is an energy propagating field It drops off ~ 1/r Ex. at 13.56MHz Fundamental Operating Principles

31. 31 Communication Technology Laboratory Wireless Communication Group –Inductive coupling Fundamental Operating Principles

32. 32 Communication Technology Laboratory Wireless Communication Group –Backscatter coupling Fundamental Operating Principles

33. 33 Communication Technology Laboratory Wireless Communication Group Communication mode Full duplex (FDX) Half duplex (HDX) Sequential (SEQ) Fundamental Operating Principles

34. 34 Communication Technology Laboratory Wireless Communication Group Coding in the baseband Fundamental Operating Principles

35. 35 Communication Technology Laboratory Wireless Communication Group Modulation schemes –Amplitude-shift keying (ASK) Changing the amplitude between two levels Modulation index: 10%…100% –Frequency-shift keying (FSK) Switching between (two) frequencies Often 2-FSK – Phase-shift keying (PSK) Switching the phase (e.g. 0 and 180 degrees) Fundamental Operating Principles

36. 36 Communication Technology Laboratory Wireless Communication Group –Load modulation The baseband signal is first modulated (ASK,FSK or PSK) using a subcarrier The modulated signal is used to switch the load resistor on and off The actual information is carried in the sidebands of the two subcarrier sidebands Fundamental Operating Principles

37. 37 Communication Technology Laboratory Wireless Communication Group Anti-collision algorithms –Tag collisions Tag collisions mean that more than one tag responds to a reader at the same time. In many cases this makes tag recognition impossible. Since low-cost passive tags cannot figure out neighboring tags or detect collisions, tag anti-collision algorithms are very important in RFID systems –Reader collisions Reader collisions occur where neighboring readers interrogate a tag simultaneously and confuse it Can be “easily” solved because readers can detect collisions and communicate with the others Multiple Access

38. 38 Communication Technology Laboratory Wireless Communication Group –Tag anti-collision algorithms Broadcast mode Reader broadcasts energy and the tags receive the transmitted data Multiple-access to a reader All transponders may react simultaneously Goal: minimize the required time for identifying all tags Multiple-access and anti-collision procedures Multiple Access

39. 39 Communication Technology Laboratory Wireless Communication Group –Time division multiple access (TDMA) Deterministic protocols –High reader to tag communication –Typically tree-walking algorithm Stochastic protocols –Less reader to tag communication –Typically ALOHA-based algorithm (e.g. slotted ALOHA) Multiple Access

40. 40 Communication Technology Laboratory Wireless Communication Group –Binary Tree (EPCglobal Class 0) Multiple Access 0101010101010101 01010101 0101 01 0001010001011000110011011111 The reader starts a tree traversal by sending the special symbol NULL followed by a binary 0 Reader: NULL, 0 Tag Reply: 00010 01000 01010 10001 11001 11011 11111 0 1 NULL Reader symbol

41. 41 Communication Technology Laboratory Wireless Communication Group –Binary Tree (EPCglobal Class 0) Multiple Access 0101010101010101 01010101 0101 01 0001010001011000110011011111 The reader hears both 0 and 1, and chooses to reply with a 0 Reader: 0 Tag Reply: 00010 01001 01011 1000(mute) 1100(mute) 1101(mute) 1111(mute) 0 1 NULL Reader symbol

42. 42 Communication Technology Laboratory Wireless Communication Group –Binary Tree (EPCglobal Class 0) Multiple Access 0101010101010101 01010101 0101 01 0001010001011000110011011111 The reader hears both 0 and 1, and chooses to reply with a 0 Reader: 0 Tag Reply: 00010 0100(mute) 0101(mute) 1000(mute) 1100(mute) 1101(mute) 1111(mute) 0 1 NULL Reader symbol

43. 43 Communication Technology Laboratory Wireless Communication Group –Binary Tree (EPCglobal Class 0) Multiple Access 0101010101010101 01010101 0101 01 0001010001011000110011011111 The reader hears only 0 and so echoes that bit Reader: 0 Tag Reply: 00011 0100(mute) 0101(mute) 1000(mute) 1100(mute) 1101(mute) 1111(mute) 0 1 NULL Reader symbol

44. 44 Communication Technology Laboratory Wireless Communication Group –Binary Tree (EPCglobal Class 0) Multiple Access 0101010101010101 01010101 0101 01 0001010001011000110011011111 The reader hears only 1 and so echoes that bit; the (simplified) EPC for one tag has been received Reader: 1 0 1 NULL Reader symbol

45. 45 Communication Technology Laboratory Wireless Communication Group –Slotted Aloha variant – Q Protocol (EPCglobal Class 1 Generation 2) The reader specifies the number of slots in the inventory round Each tag randomly chooses a location to reply within the round The reader issues short commands to mark the beginning of each slot within the round If a tag has chosen that slot, it replies with a random number If the reader can decipher the number and acknowledge it, the tag sends its EPC (Electronic Product Code) Multiple Access Inventory Query (Q) arbitrate 3 7407 winner reply each tag ‘rolls die’ 2Q2Q Reader

46. 46 Communication Technology Laboratory Wireless Communication Group –Capture effect If one tag is closer to the reader antenna than the others that tag may be able to override the data packets from the other tags as result of the greater signal strength at the reader When does a weak signal not disturb a strong signal ? The problem of “weak collisions”... Multiple Access

47. 47 Communication Technology Laboratory Wireless Communication Group RFID Systems - system design Why study operating principles ? –Selecting the RFID system that is the most appropriate for your application or business How to select an appropriate RFID system ? –For each application there is an appropriate RFID system in terms of Operating principles: frequency, range,… Functionality: read-only, read/write,… Physical form: static readers, handheld readers,… Costs  “One size fits all” approach does not work for all RFID applications !!!  RFID system design is driven by different factors

48. 48 Communication Technology Laboratory Wireless Communication Group Read range Data rates Robustness to noise Speed for reading multiple tags Costs Power Supply Coding Data Access Information Storage Anti-collision algorithms Tag Antenna Design Environment Chip Design Reader Design Standards Reader Antenna Design Coupling Frequency Modulation RFID Systems - system design