A new generation of RFID

Affordable Gen2 tags are easier to read and play well with others

RFID technology is changing. Advancements continue to make active tags smaller and more affordable so they can be used for smaller items, not just cargo containers or automobiles.

Moreover, the Generation 2 tag standard, called Gen2, brings several benefits: less signal interference with other tags when multiple readers are in use; cross-vendor interoperability; faster read rates (as much as 10 times faster); required use of a unique identifier to help validate identity; support for authentication through an optional, encrypted, nonbroadcast password; international interoperability; kill support so that a reader can disable a tag that is no longer needed; and reduced power consumption for the readers. The standard was ratified in December 2004 by the EPCglobal industry group.

Manufacturers have just begun shipping Gen2 tags. Current RFID tags are passive, reflecting a radio signal back to a reader. When the signal reaches the tag, it bounces off the embedded chip, which changes the radio signal slightly to encode its data -- similar to the way paint reflects back specific colors when full-spectrum light is shone on it. That bounce-back approach typically limits passive RFID tags' range to about 10 feet.

Active tags -- essentially transponders -- can have radio ranges of hundreds of feet, making them ideal for tracking objects in large areas. But they require a power source (usually a battery), radio, and an antenna and thus typically are the size of several decks of cards. They also cost between $40 and $80, as opposed to 10 cents for passive RFID tags. These factors combine to limit their utility to just large, highly valuable objects. The active tag readers are more costly as well.

But in the next few years, the active tags will get smaller and cheaper, making them more suitable for smaller, lower-value items, says Marcus Torchia, senior wireless analyst at Yankee Group. And because most work with the increasingly common 802.11 networks, they will easily fit into most organizations' IT infrastructure, he says.

"Add some software and active RFID tags, and you can know the exact location of an asset," Marcus says. Plus, active tags eliminate the need for portals or gates that are used in passive RFID environments to funnel objects close enough to the readers. According to Torchia, active tags also allow for more applications by offering two-way communications, sensor integration, independent system intelligence, and constant visibility.


Copyright © 2005 IDG Communications, Inc.

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