RFID 技术及其应用

1、 a brief introductionGang Wang, Ph.D.Dept. of Telecommunication EngineeringJiangsu UniversityWhat is RFID?RFID is an ADC technology that uses radio-frequency waves to transfer data between a reader and a movable item to identify, categorize, locate, track.RFID is fast, reliable, and does not require

2、 physical sight or contact between reader/scanner and the tagged itemOne or more RF tagsTwo or more antennasOne or more interrogatorsOne or more host computersRFID PrimerRFID Diagram:Host ComputerNote: The host is the software database. ReaderAntennaRFID PrimerRFID Diagram:Note: The Reader interpret

3、s radio frequency into digital information.RFID PrimerRFID Diagram:Note: The RF module creates radio frequency (RF). It receives and transmits RF through the antennaRFID PrimerRFID Diagram:Note: Tag (transponder) is interrogated by the antenna.RFID PrimerRFID Diagram:Note: The antenna captures the t

4、ag ID numberfirst as analog RF waves, then it is converted to digital information.(Tag ID Communication)ReaderRF ModuleTagAntennaHost ComputerAn RFID Tag Is A Portable DatabaseA sophisticated computing and communications deviceA wireless extension of Information SystemsInterrogation UnitTx/RxMicroCo

5、mputerComputer NetworkAntennaTagRadio Tx/RxRAMROMCPUI/OPwr SupplyRadio Tx/RxRAM ROMCPUI/OPwr SupplyWhat is RFID? - The TagsTags can be read-only or read-writeTag memory can be factory or field programmed, partitionable, and optionally permanently lockedBytes left unlocked can be rewritten over more

6、than 100,000 timesWhat is RFID? - The TagsTags can be attached to almost anything: pallets or cases of product vehicles company assets or personnel items such as apparel, luggage, laundry people, livestock, or pets high value electronics such as computers, TVs, camcordersAre All Tags The Same? Three

7、 Basic Types:4Active Battery powered memory, radio & circuitryTag transmits radio signalHigh Read Range (300 feet)4Active BackscatterBattery powered memory and circuitryTag reflects radio signal from readerMedium Read Range (10 - 50 feet)4Passive BackscatterReader poweredTag reflects radio signa

8、l from readerShorter Read Range (4 inches - 15 feet)Backscatter Active Tag Operation Interrogator maintains CW signal Tag modulates diode with baseband signal to reflect time slices of CW back to interrogator Interrogator receives and demodulates reflected signalInterrogatorTagRXTXAre All Tags The S

9、ame? Variations:MemorySize (16 bits - 512KBytes +)Read-Only, Read/Write or WORMType: EEProm, Antifuse, FeRamArbitration (Anti-collision)Ability to read/write one or many tags at a timeFrequency125KHz - 5.8 GHzPhysical DimensionsThumbnail to Brick sizes Price ($0.50 to $250)Types of RF TagsTypeData C

10、apacityWrite/ReadProgram byApplicationEAS1 bitread-onlyuserRetail SecuritySAW4 to 16 bitsread-onlymanufacturerInductive2 to 32 bytesread-onlymanufacturerModulatedBackscatter32 to 2K byteswrite/readuser(tag ID may be by manufacturer)Portable Data FileActive/ModulatedBackscatter32 to 2K byteswrite/rea

11、dPortable Data File2K bytes to16 Mbyteswrite/readinterrogate/modify/readDynamic Data FileActiveuser(tag ID may be by manufacturer)user(tag ID may be by manufacturer)License PlateIgnition KeyProprietaryTechnologyTypes of TagsMemory Segmentation Read Only (Factory Programmed)WORM - Write Once, Read Ma

12、ny timesReprogrammable (Field Programmable) Read/Write (In-Use Programmable)What is RFID? - The ReadersReaders (interrogators) can be at a fixed point such as Entrance/exit Point of sale WarehouseReaders can also be mobile - tethered, hand-held, or wirelessInductive (E-Field)Electromagnetic (H-Field

13、)8Narrowband8Spread SpectrumFrequency HoppingDirect SequenceInductive Magnetic Field Coupling: 300 MHz 1mTag size smaller than 13.56 MHz Smaller antennasRange: licensed to 20-40 with reasonable sized tag (stamp to eraser size)Good non-line-of-sight communication (except for conductive, lossy materia

14、ls)High data rate; Large amounts of DataControlled read zone (through antenna directionality) DisadvantagesDoes not penetrate water/tissue Regulatory issues (not available in many countries) Regulatory issues in Europe (similar band 869 MHz requires dual-freq chip)DSI III recommends 862 to 870 MHz i

15、n the EU, may not be available elsewhereElectromagnetic Field Coupling: 2.45 GHz AdvantagesTag size smaller than inductive or UHF (1x 1/4) Range: greater range thaninductive w/o batteryMore bandwidth than UHF (more frequencies to hop)Smaller antennas than UHF or inductiveHigh data rateAdvantagesGood

16、 non-line-of-sight communication (except for conductive, lossy materials)Can store large amounts of DataControlled read zone (through antenna directionality)Effective around metals with tuning/design adaptationsDisadvantagesMore susceptible to electronic noise than UHFShared spectrum with other tech

17、nologies-microwave ovens, WLANs, TV devices, etc.Requires non-interfering, good neighbor tactics like FHSSCompetitive requirement: single chip-highly technical; limited number of vendorsRegulatory approvals still in process5.8 GHz (European Road Telematics Frequency)Advantages:Less congested band/le

18、ss interferenceDisadvantages: Not available in U.S. or many other countries (5.9 now in FCC review)Must orient antennas carefullyRange limited (due to scaling issues/wavelengths)Chip difficult to buildExpensiveVarious TagsApplicationsSuccessful ApplicationsApplications in DevelopmentVisibility at Wa

19、rehouse Dock Doors with Smart LabelsSmart ShelvesVehicle Inventory ManagementNewly Assembled Vehicles Stored in YardThousands of Vehicles must be Shipped per Day by Various ConveyancesAssembling Shipments is Complex OperationUnfound Vehicles Cause Significant DelaysDelays Cost Manufacturer $5-$10/Da

20、y/VehicleVehicles Shipped with Quality Problems Cost Thousands of Dollars to Repair After ShipmentIncomplete Loads Require Additional TransportsRTLS 802.11 Empower Mobile Real Time DecisionsRTLS Speeds Finding VehiclesVehicles are Checked Real Time for ship/hold status Using 802.11 Wireless NetworkR

21、TLS Identifies Vehicles in Overflow YardsLoaded Vehicles Status is VerifiedManufacturing ManagementFeatures Real-time Visibility of All W-I-P on Site Current Location Location History and Trace-ability Automate Receive, Put-away, Pick and Ship Status Information Benefits Reduced Material Handling Co

22、sts Reduced Expediting Costs Reduced Obsolete Inventory No Line SwitchoversULD Tracking at AirportsAirline Baggage TrackingGround Support Equipment TrackingLocate GSE InstantlyMonitor Utilization and Status Via Telemetry “On Time” Oil Pressure, Battery Level, etc Yard ManagementDistribution, Manufac

23、turing and Shipping YardsFeatures Real-time visibility of all trailers on site Current location Location history and trace-ability Visual client alerts Trailer status informationBenefits Eliminate Yard Checks Improved yard operationsThroughput - Utilization Reduced spoilage Reduced demurrage feesPay

24、back Less than 12 monthsHow to Evaluate Your NeedsIdentify hardware requirements: What will be identified, tracked, located What read distance and field of view (FoV) is required How many tags in the FoV at the same time What amount and type of data will be stored Must data be updated Will tags be m

25、oving and how fast What are limits on tag size, shape, and orientation Will tags be disposable or reused Will tags be operating in cold, wet, dirty, hot, steamy, muddy, dusty environment What are regulatory constraints in the nation(s) of useIdentify software requirements:4Will the new RFID solution integrate with legacy system software and solutions4Must new interface software be developed4What type of data formats must be supported4What communications protocols must be supported4How must the current software change to accommodate the advantages of “write” technology? Bui