Introduction to RFIDIntroduction to RFID

RFID ProgrammingRFID ProgrammingUniversity of HoustonUniversity of HoustonBauer College of BusinessBauer College of BusinessSpring 2007Spring 2007

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 used for electronic and wireless identification of objects, humans and animals

RFID History

“People say the Internet happened quickly. They’re crazy. It took forever!”

Robert Taylor

APRA IPTO Director

RFID History: Ancient TimesDecade Event

1940-1950

RadarHarry Stockman “Communication by Means of Reflective Power”, 1948

1950-1960

Early exploration“Identification, friend or foe” (IFF)

1960-1970

Further scientific explorationCompanies: Checkpoint, Sensormatic, KnogoElectronic Article Surveillance (EAS)

1970-1980

Explosion of RFID developmentApplications: animal tracking, vehicle tracking, factory automation

1980-1990

Commercial RFID applications enter mainstream

1990-2000

RFID becomes a part of daily lifeHarris County Toll Road Authority, 1992

Source: AIM, Inc, 2001 (URL: www.aimglobal.org/technologies/ rfid/resources/shrouds_of_time.pdf

Mandates

Mandates

Wal-Mart – An update October 2005

out of stocks reduced up to 16% out of stock items with EPCs replenished 3 times faster

stores with RFID 63% more effective in restocking items 10% less manual orders, reduced excess inventory

helps make sure that promotional displays are delivered and in place so that products are in our stores and ready for sale when the advertising begins

Shortens time for new items to make it to store shelves

Aids in proof of delivery & purchase order reconciliation - provides product visibility even after it has left receiving dock

> 600 suppliers expected to be on board by 2007

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

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

Electromagnetic Interference - Interference caused when the radio waves of one device distort the waves of another. Cells phones, wireless computers and even robots in factories can produce radio waves that interfere with RFID tags.

EI is likely to be an issue for UHF systems

Tags Characteristics

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

Expensive

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

RFID Evolution (Gartner, 2003)

RFID Growth

Several market research firms predict that ~2007 RFID market will reach ~$3 billion

Questions?