Introduction to RFID RFID Programming University of Houston Bauer College of Business Spring 2007.

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 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

Mandates

Mandates

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 speed

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 (OGS)

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

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 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 Programming Options

Read-only Cheap

Write once read many Read/write

Expensive

Why Use Read/Write Tags?

Greater flexibility Customers may change requirements Standards may change

Database dependence Ownership issues Lag times

Tag Physical Forms

Disk and Coins – can be attached to an item by a fastening screw

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

Readers

What’s so special about RFID? 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 Enterprise value of data collection

Example: a big retailer working with small suppliers

The data collection process is relatively chaotic Example: Battlefield Making libraries chaotic

The exact configuration of goods must be maintained

Inventory tracking

RFID tag data capacity is big enough that any tag will have a unique code, while current bar codes are limited to a single type code for all instances of a particular product.

The uniqueness of RFID tags means that a product may be individually tracked as it moves from location to location, finally ending up in the consumer's hands. This may help companies to combat theft and other forms of product loss.

the visibility provided by RFID allows an accurate knowledge on the inventory level by eliminating the discrepancy between inventory record and physical inventory. In an academic study performed at Wal-Mart, RFID reduced

Out of Stocks by 30 percent for products selling between 0.1 and 15 units a day.

It has also been proposed to use RFID for POS store checkout to replace the cashier with an automatic system which needs no barcode scanning. However, this is not likely to be possible without a significant reduction in the cost of current tags

Some applications

transportation payments library tracking, pallet tracking, building access control, airline baggage tracking, apparel and pharmaceutical items tracking. identification badges, shipping container tracking, and truck and trailer tracking

in shipping yards. car keys.

RFID Growth

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

The lowest cost of Gen2 EPC inlay is offered by SmartCode at a price of 5 cents apiece in volumes of 100 million or more

Standards

The manufacturer, distributor and retailer must all have systems that are compatible with one another.

This doesn’t just apply to back-end systems, but to the tags themselves if RFID is to be effective.

Some of the early compatibility issues were very fundamental — such as the frequency the tags operate on.

For the most part, the 869 to 915 MHz tags prevailed, but still left the hurdle of the actual tag content.

It became obvious that tag formats, just like barcode formats, needed standardization.

This was addressed through the Electronic Product Codes (EPCglobal), an industry body that sets these electronic standards.

Standards

However, having the frequency and tag format agree only buys so much if the air protocol to get the data isn’t established.

Until recently it was difficult to guarantee that a reader from one manufacturer would work with a tag from another, until the EPC Generation 2 air specification.

Now, both tag and reader vendors all signed up to make their equipment compatible

All manufacturers has cross compatible offerings.

Standards

While the EPC now has a standard adopted by the vendors in the US and Europe, there continue to be difficulties with international compatibility. Almost all of the participants in EPC are from the U.S. and Europe, while a significant portion of manufactured goods are no longer made in those member countries.

As respected as EPC may be, it would require a higher authority to mandate a world-wide standard.

That’s where the International Standards Organization (ISO) comes in.

The EPC Generation 2 specification was submitted to ISO and just recently it became an approved standard with the designation ISO/IEC 18000 to 6C.

With ISO approval, it’s now possible to buy a compliant Reader and tag that works the world over.

Regulations

Europe faces significant problems with reader performance degradation in environments where high numbers of readers are used together.

This performance degradation issue originates from the fact that the EU has a more limited range of spectrum that’s legally assigned for RFID use compared to the USA.

Regulations In North America, UHF can be used unlicensed for 902 – 928

MHz (±13 MHz from the 915 MHz center frequency), but restrictions exist for transmission power.

In Europe, RFID and other low-power radio applications are regulated by ETSI recommendations EN 300 220 and EN 302 208, and ERO recommendation 70 03, allowing RFID operation with somewhat complex band restrictions from 865–868 MHz.

Readers are required to monitor a channel before transmitting ("Listen Before Talk"); this requirement has led to some restrictions on performance, the resolution of which is a subject of current research.

The North American UHF standard is not accepted in France as it interferes with its military bands.

For China and Japan, there is no regulation for the use of UHF. Each application for UHF in these countries needs a site license, which needs to be applied for at the local authorities, and can be revoked.

For Australia and New Zealand, 918 – 926 MHz are unlicensed, but restrictions exist for transmission power.

Privacy

Since the owner of an item will not necessarily be aware of the presence of a RFID tag and the tag can be read at a distance without the knowledge of the individual, it becomes possible to gather sensitive data about an individual without consent. (Ex. Scanning your home, medical records)

A number of products are available on the market in the US that will allow a concerned carrier of RFID-enabled cards to shield their data

Shielding is again a function of the frequency being used. Low-frequency tags, like those used in implantable devices

for humans and pets, are relatively resistant to shielding, though thick metal foil will prevent most reads.

High frequency tags (13.56 MHz — smart cards and access badges) are more sensitive to shielding and are difficult to read when within a few centimetres of a metal surface.