RFID
Technology & Application
Auto-ID Technologies
Barcode
Systems
Biometric
Systems
Auto-ID
Smart
Cards
Optical
Character
Recognition
(OCR)
RFID
Outline
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•
•
•
•
RFID Overview
RFID Technology Internals
RFID Applications
RFID Issues
RFID Case study
RFID Overview
What is RFID?
• RFID = Radio Frequency IDentification
– Uses radio-frequency waves to transfer data
between a reader and a movable item to identify,
categorize, track..
– Does not require physical sight or contact between
reader/scanner and the tagged item.
– Attempts to provide unique identification and
backend integration that allows for wide range of
applications.
RFID System Components
• Tag
– Chip
– Antenna
• Reader
– RF Module (Transmitter and Receiver)
– Control Unit
– Antenna
– Several Interfaces (RS 232, USB, etc.)
• Host Computer
– Middleware
Ethernet
RFID System Components
RFID
Reader
RFID Tag
RF Antenna
Network
Workstation
RFID Tag Structure(General)
Antenna
Power Supply
Tx Modulator
Control Logic
(Finite State
machine)
Rx
Demodulator
Tag Integrated Circuit (IC)
Memory
Cells
RFID Tags – Smart Lables
A paper label
with RFID inside
An antenna,
printed, etched
or stamped ...
… and a chip
attached to it
… on a substrate
e.g. a plastic
foil ...
RFID Tags – More Examples
RFID Tag Types
• Passive Tags
– Operational power from
reader radiated power
• Active Tags
– Operational power provided
by battery(built into tag)
RFID Tag Comparison
Passive
Power Source Powered by reader
Read Range Shorter (4 inches to
15 feet)
Lower data rate
Data Rate
Lower (few bits to 1
Storage
KB)
Noise
Subject to noise
Costs
Around 25 cents to
few dollars
Active
Battery powered
Longer (300 feet)
Higher data rate
Higher (512 KB)
Better noise
Immunity
Around 50 to 250
dollars
RFID Readers
• Functions:
– Remotely power tags
– Establish a bidirectional data link
– Communicate with networked server(s)
– Can read 100-300 tags per second
• Readers can be at a fixed point such as
– Entrance/exit
– Point of sale
• Readers can also be mobile/hand-held
RFID Reader Structure
RFID Readers - Anatomy
Digital Signal
Processor
(DSP)
Network
Processor
Power
Supply
915MHz
Radio
13.56MHz
Radio
RFID Readers - Examples
RFID Tech Internals
Information Acquiring Methods
• Inductive Coupling
– For getting data from proximity card – passive tags
• Propagation Coupling
– For reading tags working in a larger distance
Inductive Coupling
• Based on the stored data, the micro chip of
the tag controls the switching on and off of a
load resistance which will influence the
voltage in the reader’s antenna.
• Then the reader can detect the voltage
changes in its own antenna.
Inductive Coupling
• The electro-magnetic field from the reader
penetrates the coil of the tag in a shorter
distance.
• By induction, a voltage is generated in the
tag’s antenna coil.
• This voltage is rectified and servers as the
power of the tag.
Inductive Coupling
Inductive Coupling - shorter distance
IC or microprocessor
Transceiver
Tag Reader
RFID
Tag
antenna
antenna
Propagation Coupling
• Basic Principle:
– The electromagnetic waves are reflected by
objects with dimensions greater than around half
the wavelength of the wave.
Propagation Coupling
• A small portion of the electromagnetic power
of the reader reaches the tag.
• This power can be also used as the power
supply for the tag (passive tag).
• Based on the stored data, the micro chip alters
the load connected to the tag’s antenna and
then changes the reflection characteristics of
the antenna.
• Then the reflected RF energy arrives at the
reader’s antenna.
Propagation Coupling
Propagation Coupling – longer distance
IC or microprocessor
Transceiver
Tag Reader
RFID
Tag
antenna
antenna
Data Transfer
• Amplitude Shift Keying (ASK)
– Changing the amplitude of the radio wave based
on the digital (binary ) data
• Frequency Shift Keying (FSK)
– Switching between two different frequencies
based on the digital (binary) data
• Phase Shift Keying (PSK)
– Changing the phase on the transition between a 0
to 1 or 1 to 0
RFID Communications
Power from RF field
Reader
Antenna
Commands from reader
Reader
Tag->Reader Responses
Tags
RFID Communication
Channel
RFID Frequencies
Band
120-150 KHz (LF)
Range
< 10 cm
Data speed
Power Source
Remarks
Low
Generally
passive tags
Generally
passive tags
Smart cards
Animal identification, factory
data collection
13.56 MHz (HF)
<1m
Low to moderate
433 MHz (UHF)
1-100 m
Moderate
Active tags or
passive tags
Defence applications, with active
tags
868-870 MHz
(Europe)
902-928 MHz
(North America)
UHF
1-2 m
Moderate to
high
Active tags or
passive tags
Various standards
2450 MHz
5800 MHz
(microwave)
1-2 m
High
Active tags or
passive tags
802.11 WLAN, Bluetooth
standards
3.1 Ghz-10 GHz
(microwave)
to 200 m
High
Active tags
Requires active tags
RFID Frequency Trade-Offs
Frequency




Power
Cost
Bandwidth
Line of Sight


Lifespan
Range
RFID Applications
RFID Application
• Manufacturing and Processing
– Inventory and production process monitoring
– Warehouse order fulfillment
• Supply Chain Management
– Inventory tracking systems
– Logistics management
• Retail
– Inventory control and customer insight
– Auto checkout with reverse logistics
RFID Application
• Security
– Access control
– Counterfeiting and Theft control/prevention
• Location Tracking
– Traffic movement control and parking
management
– Wildlife/Livestock monitoring and tracking
RFID Application – Smart Groceries
• Add an RFID tag to all
items in the grocery
• As the cart leaves the
store, it passes through
an RFID transceiver.
• The cart is rung up in
seconds.
RFID Application – Smart Cabinet
Reader antennas placed under each shelf
Passive
read/write tags
affixed to caps
of containers
1.
Tagged item is removed
from or placed in
“Smart Cabinet”
2.
“Smart Cabinet”
periodically
interrogates to assess
inventory
3.
Server/Database is
updated to reflect
item’s disposition
4.
Designated individuals
are notified regarding
items that need
attention (cabinet and
shelf location, action
required)
RFID Application – Smart Fridge
•
•
•
•
Recognizes what’s been put in it
Recognizes when things are removed
Creates automatic shopping lists
Notifies you when things are past their
expiration
• Shows you the recipes that most closely
match what is available
More Smart Applications
• “Smart” products
– Clothing, appliances, CDs, etc. tagged for store
returns
• “Smart” paper
– Airline tickets that indicate your location in the
airport
• “Smart” currency
– Anti-counterfeiting and tracking.
• “Smart” people? “Smart” planet? …
RFID Issues
Reader Collisions
• It occurs when the coverage area of one
reader overlaps with that of another reader.
• The RF fields of two or more readers may
overlap and interfere.
Reader 1
Tag
Reader 2
Reader Collisions
• TDMA based solutions:
– Program the reader to read at fractionally
different times
– Assign different time slots to nearby readers
• Other solutions?
Tag Collisions
• It occurs when multiple tags are in range of
the reader. All the tags will be activated and
respond at the same time.
– Signal interference may occur.
– It is difficult to distinguish between the tags.
Tag1
Tag2
Tag4
Reader
Tag3
Security Issues - Eavesdrop
Reader
Tag
Backward Channel Range
Forward Channel Range
Eavesdropper
Other Security Issues
•
•
•
•
Forge valid tags
Attack the RFID infrastructure
Wiping out inventory data
Interrupting the normal reading
RFID – The complete picture
RFID Case Study
RFID Case Study
• TRF7960A EVM
• ISO/IEC 14443
• Demo
TRF7960A EVM
• TRF7960A Evaluation Module
– Texas Instrument
– Multiple protocol RFID reader
– For RFID study and research
– Build RFID applications
– $101
TRF7960A EVM
• Features
– Support ISO 15683, 14443 A&B, Tag-it protocol
– Has an on-board PCB antenna
– Has an interface for testing
– Provides a Windows based host UI
– Provides a USB interface
– Provides source codes & detailed docs
TRF7960A EVM
TRF7960A EVM
• RF Test Interface
– Use SMA connector
– For reader testing
– External amplifier or antenna
– Should remove one specific resistor
ISO 14443
ISO 14443
• ISO/IEC 14443
– Proximity integrated circuit cards
– Four parts
•
•
•
•
Physical characteristics
Frequency & Power & Signal interface
Initialization & Anticollision
Transmission protocols
– Communication interface
• Type A
• Type B
ISO 14443
• ISO/IEC 14443
– Proximity integrated circuit cards, up to 10cm
– Four parts
•
•
•
•
Physical characteristics
Frequency & Power & Signal interface
Initialization & Anticollision
Transmission protocols
– Communication interface
• Type A
• Type B
ISO 14443 Type A & B
Reader to Card (PCD > PICC)
Frequency
Modulation
Bit coding
Data rate
Card to Reader (PICC > PCD)
Modulation
Bit coding
Subcarrier
Bit coding
Data rate
Type A
13.56 MHz
100% ASK
Modified Miller
106 kb/s
Type B
13.56 MHz
10% ASK
NRZ
106 kb/s
Load
OOK
847kHz
Manchester
106 kb/s
Load
BPSK
847kHZ
NRZ
106 kb/s
ISO 14443 Type A & B
Demo
References
• [1] http://www.cs.unc.edu/~sparks
• [2] Introduction to RFID. Vlad Krotov. Uni. of
Houston, Bauer College of Busines.
• [3] www.it.iitb.ac.in/~sri
• [4] RFID Handbook.Ramiro Liscano.
“Introduction to Bluetooth Networking ”.
• [5] www.rfidjournal.com