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TRANSCRIPT
Introduction to RFIDIntroduction to RFID
Vlad KrotovVlad Krotov
DISC 4397 – Section 12977DISC 4397 – Section 12977 University of HoustonUniversity of Houston
Bauer College of BusinessBauer College of BusinessSpring 2005Spring 2005
Some links…
• www.rfidjournal.com
• www.computerworld.com
• www.rfidusa.com
• RFID Handbook
• www.uh.edu/gartner
Auto-ID Technologies
BiometricSystems
Smart Cards
RFID
OpticalCharacter
Recognition(OCR)
BarcodeSystems
Auto-ID
Definition
• RFID (Radio Frequency Identification) is a technology that enables the electronic and wireless labeling and identification of objects, humans and animals
RFID Principal System Components
• Tag (Transponder)– Chip– Antenna
• Reader (Interrogator)– RF Module (Transmitter and Receiver)– Control Unit– Antenna– Several Interfaces (RS 232, RS 485, etc.)
• Host Computer– Middleware
RFID System Architecture
EPC RFID Architecture
EPC RFID System Architecture
Carrier Frequencies
• What is frequency?– Refers to the property of radio waves used to
transmit data– Roughly speaking, it is the intensity of waves
used to transmit information
Carrier Frequency
• RFID systems may use a particular frequency band depending on:– Application– Legislature– Cost considerations
Frequency BandsFrequency Band Characteristics Typical
Applications
Low
100-500 kHz
Short to medium read range, inexpensive, low reading speed
Access control
Animal/Human identification
Inventory Control
Medium
10-15 MHz
Short to medium read range
Potentially inexpensive
Medium reading range
Access Control
Smart Cards
High
UHF: 850-950MHz
Microwave: 2.4 – 5.8 GHz
Long read range
High reading speed
Line of sight required (Microwave)
Expensive
Railroad car monitoring
Toll collection systems
Coupling
• 100kHz – 30 MHz – inductive coupling
• HF and Microwave systems use electromagnetic coupling
Coupling
Frequency and bandwidth
• Frequency is of primary importance when determining data transfer rates (bandwidth)
• The higher the frequency, the higher the data transfer rate
Range
• Range – the working distance between a tag and a reader
Range
Range and Power Levels
• The range that can be achieved in an RFID system is determined by– The power available at the reader– The power available within the tag– The environmental conditions and structures
• More important at higher frequencies than at lower frequencies
– 100-500mW
Material Propagation
• The absorption rate for water and other non-conductive substances is lower by a factor of 100 000 at 100 kHz than it is at 1 GHz
• LF systems are primarily used due to their high propagation of substances
Electromagnetic Interference
• What is electromagnetic interference?
• LF (inductive coupling) RFID systems suffer from electromagnetic interference more than UHF and Microwave
• Microwave systems are more likely to be used in manufacturing (auto-industry)
Tags Characteristic
• Means by which transponder is powered
• Data carrying options
• Data read rates
• Programming options
• Physical forms
• Costs
Active and Passive Tags
• Active tags– Powered by an internal battery– Finite lifetime (because of battery)– Greater range– Better noise immunity– Higher data transmission rates
Active and Passive Tags
• Passive tags– Operate without battery– Derive power from the field generate by the
reader– Less expensive– Unlimited life– Subject to noise– Require more powerful readers– Orientation sensitivity
Data Carrying Options
• A tag can contain– An identifier
• 1bit – 128 bits
– Portable data files• Example: 64 K
Data Read Rate
• Data read rate is linked to frequency– The higher the frequency, the higher the read
rate
Data Programming Options
• Read-only– Cheap
• Write once read many (WORM)
• Read/write– Expansive
Why Use Read/Write Tags?
• Greater flexibility– Customers may change requirements– Standards may change
• Database dependence– Ownership issues– Lag times
• High risk applications
Tag Physical Forms
• Disk and Coins – can be attached to an item by a fastening screw
Tag Physical Forms
• Mount-on-Metal – special construction minimizes impact of metal in terms of interference
Tag Physical Forms
• Keys or Key Fobs, Watches – access control
Smart Labels
• A bar code can be printed on an RFID label
Tag Physical Forms
• Glass Transponders can be implanted under skin
What’s so special about RFID?
• Unifying Auto-ID technology
• Line of sight is not required
• Longer read ranges
• Faster: hundreds of items can be scanned in one read
RFID vs. Barcodes
Principles of Profitable RFID Use
• Bar codes are unfeasible– Example: rail cars
• Damage• Speed
• Counting Processes – Greater speed– Saves manual labor
Principles of Profitable RFID Use
• Personal responsibility doesn't match the enterprise value of data collection– Example: a big retailer working with a small
supplier
• The data collection process is relatively chaotic– Example: Battlefield– Making libraries chaotic
Principles of Profitable RFID Use
• The exact configuration of goods must be maintained– Example: Auto industry
• Data must be collected from consumers outside of the retail– Warning: Privacy Concerns
RFID Evolution (Gartner, 2003)
RFID Growth
• Several market research firms predict that ~2007 RFID market will reach ~$3 billion
Questions?