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What Is RFID Technology?

What Is RFID Technology?

Now that I have stuck my neck out on how passive RFIDs are, and how the work of correlating the presence information is done elsewhere, I thought I should get something closer to the real facts.

The site RFID Talk: Discussion of RFID technology  provides a discussion portal for matters RFIDian.  There is an RFID Technology forum on the site.  Many of the topics are about specific products.  It is interesting that RFIDs are described as transponders.  I am looking into some of the specific discussions.

It appears that the typical RFID returns something like an EPC, an Electronic Product Code prefered by Walmart and the US DoD.  The passive tags are cheaper, can be polled indefinitely, and are the ones likely to be ubiquitous in the near future.  These, like the Hitachi u-chip, have small (e.g., 128 bit) ROMs and are not alterable after manufacture.  They are physically miniscule and the power for their response is derived from the scanner's UHF signal.

There are also active tags.  The ones being used to monitor truck tires, with 8-kilobit memories and environmental sensors, can report temperature and pressure histories for the tires they are affixed to.

Zebra Technologies offers RFID Printing Solutions.  An RFID embedded in a product label is programmed with its identifier, such as an EPC, simultaneous with the printing of visible identification (even bar codes) on the label itself.  The distinction between the soon-to-be-ubiquitous passive tags and active tags is explained in another Zebra Fact Page:

"Information is sent to and read from RFID tags by a reader using radio waves. In passive systems, which are the most common, a Radio Frequency Identification reader transmits an energy field that 'wakes up' the tag and provides the power for the tag to operate. In active systems, a battery in the tag is used to boost the effective operating range of the tag and to offer additional features over passive tags, such as temperature sensing."

In all near-term cases, the information carried by the tag is limited, whether or not alterable.  Some connection to a datasystem is required to correlate the current scanning, and collateral information (e.g., a cash-register feed for purchases) to any kind of global record.  The requirements for the data-communication and database end are considered to be immense.

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This little appendage is provided to force Blogger to see this article as having changed.  There's really no new content.  I am making this modification so that the Atom feed will supplant the previous modification that was published as a result of this defect.

posted by orcmid at 6/27/2004 05:31:25 PM