The tests showed that not all tag models perform well in global operations. The EECC tested the 20 tags across a range of frequencies used throughout the world, from 800 MHz to 1,000 MHz. "What we were looking for is a global tag," Wolfram says. "What we found is that some tags work better in the United States and Europe than in Asia, because they are tuned to [the
frequency band used in] that environment."
Moreover, the EECC discerned wide variations among the tags' orientation sensitivity—the change in read rates caused by a tag's position on an object and its consequential orientation to an interrogator's
antenna. For some tag models, orientation had a big effect on read rates. Tag models also showed a wide variation in
read range, some proving readable from a distance of 10 meters. Sometimes, Wolfram notes, it is not only read range in
free air that determines performance on a special mounting material, but production consistency as well. These findings are documented in the report, which was first presented in May at a conference held for Metro suppliers.
According to Wolfram, Metro asked the EECC to carry out the tests because the retailer had observed quality differences among tags on the market. It wanted to apply the study's results to its own internal RFID use, and to make the results available to hundreds of Metro suppliers, system integrators and other RFID users gearing up to tag objects being shipped to Metro. The report, entitled "
UHF Tag Performance Survey," can be purchased online for €595 ($811), with a 25 percent discount available to EPCglobal subscribers.
"It's very important to have tags with good performance and high production consistency," says Wolfram. "In the past, companies could rely only on what tag makers promised."
The tests were sponsored by
Intel, which did not supply any of the chips or tags that the EECC tested (the chips used in the tested tags were made either by Alien,
NXP Semiconductors or
Impinj). Intel opted to support the tests because it hopes the report will increase transparency in the market. Network services company
T-Systems also provided sponsorship as part of its efforts to foster the adoption of RFID technology.
Since the tag test has been standardized, the report can be expanded in the future to include more tags and additional testing. There is no cost to tag makers for participation in the tests.