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FCC RFID Workshop RFID DiscussionsSeptember 7, 2004

Kevin Powell, Symbol Technologies

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RFID Market Direction

Convergence around the Electronic Product Code (EPC) as the standard

Wal-Mart's RFID-Using Suppliers to Exceed 100

Pilots with eight key suppliers

eWeek June 14, 2004

Defense Department will require its suppliers to put RFID tags on shipments by January 2005 to better manage its inventory. Aviation Week

EPC Pallet and case tagging mandates – PASSIVE tags

Defining the Gen 2 Standard

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The Goal is Asset Visibility … Everywhere!

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EPC Standards Glossary

Class 0 (available): Generation 1, protocol 0 Factory programmed ID

Class 1 (available): Generation 1, protocol 1 Write Once ID

UHF Generation 2 (future): Single Gen2 protocol Variety of memories & features First products in 2005

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Readers and Antennas

AR400 Reader

High Performance Antenna

General Purpose Antenna

SR400 Reader

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Handheld with RFID

Supports:

Same ruggedness and ergonomic as the MC-9000G

Antenna (front-mounted)and additional electronics add the ability to read and write either EPC Class 0 or Class 1 RFID tags

Integrated wireless networking

RFID 2D bar code

“all in one”

1D bar codes &

simultaneously

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EPC-Compliant RFID Tags

Plastic Tag Carton Tag

Glass TagConcrete Tag

Plastic Bottle Tag

Generic TagVariety of tags for different materials and applications Class 0/0+

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Basics - RFID System

A tag stores information and exchanges it by radio signal

Passive RFID Tag

Reader commands the tag & simultaneously listens for responses

RF modulator

MemoryPower recovery

Digital logic

Radio Signal

RFID Protocols

} Three EPC Communication Protocols for UHF

EPC Class 0 (Invented by Matrics)EPC Class 1 (Invented by Alien

Technologies)EPC Gen2 under development

RF demodulator

Oscillator

All in 10 microwatts!

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Passive RFID System Design

Passive Tag Constraints Battery-less – RF field powered ONLY, thus: Total consumed power < 10 W (10M range), and Simple demodulator (amplitude – 1bit/Hz style) Simple modulator (1 transistor – square wave out) Backscatter (modulated RCS) only Tx method

Passive Tag Results Very wide band response (effective antenna BW)

in receiver as well as backscatter(but at low levels) Confined to relatively inefficient reader modulation

encoding methods (simple tag demod).

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Passive RFID System Design

Reader Constraints Must energize tag (transmit) while in receive mode = Receive –50dBm while transmitting +30dBm Avoid noise sources

– Reader transmit & receive circuitry– Other backscatter sources, ie fluorescent lighting

Reader Results Extremely low noise design necessary to properly

receive tag signals while transmitter is on. Detect and avoid other high power RF devices. Shift receiver away from noise sources.

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RFID Frequency Sources

Reader TxReader CW

Fluorescent 20-40kHz

Tag -

baseb

and

Tag – Gen2 Subcarriers

Channel Edge

Channel Edge

Tag – Class 0 Subcarriers

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Passive RFID Trends

Better tag designs/protocols = lower power

Year Tag Dist Rdr pwr Tag field Rdr Rx

2000 10’ +30dBm 600W -45dBm

2002 25’ +30dBm 100W -60dBm

2004 50’ +30dBm 25W -75dBm

2006 75’ +30dBm 11W -82dBm

2008 100’ +30dBm 6W -87dBm

Note – Fluorescent interference approx –60dBm

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Gained Knowledge

Reader signals interfere with tag signals at thousands of feet separation.

Reader signals interfere with other reader transmissions at less than 100 feet.

80-100 dB range between Reader and Tag leads design to a separation of disparate power levels such that: Reader signals ONLY contend w/ other readers Tag signals ONLY contend with other tags

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Conclusions, Requests

As technology improves tag distances, the impact of noise (self, and fluorescent) becomes severe; the available technology is near the limit.

Technology improvement comes on the heels of the ability to remove the tag response from noise.

Request - allow readers on even channels, tag response on odd channels (or similar) as an optional channel use model.

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Thank You

Questions?

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