Dec 04, 2002Dec. 3, 2002 - Much of the media attention given to the Auto-ID Center has focused on its development of an RFID tag in the UHF range (868 MHz to 930 MHz). That's because UHF tags can provide the read range needed to track pallets and cases in warehouses. But shorter-range 13.56 MHz tags may be more suitable for tracking products on shelves.
Tagsys, a French company that provides customized RFID systems, has particular expertise in 13.56 MHz technologies. So Philips Semiconductor tapped the company to partner on the world's first 13.56 MHz system for reading the Auto-ID Center's electronic product code (EPC). The two companies demonstrated prototype tags and a fixed reader at the center's board meeting last month.
Fifty bottles of shampoo were placed on a flat-bed antenna module to simulate a shelf. Each bottle was equipped with a Philips 13.56 MHz EPC tag, which was read as the bottle was placed on the "shelf." When a pack of six bottles was removed, the system immediately detected that the bottles had been removed. When the six bottles were put back on the shelf, the system recorded their presence again.
The advantage of 13.56 MHz for retail applications is that radio waves at that frequency are not affected by metal and water as much as at UHF, and the reader field is more uniform. UHF readers produce a field that has null spots – holes where there is no coverage. Products in those spots would not be read properly.
"We are a strong supporter of a mixture of UHF and 13.56 MHz within the whole supply chain," says Alastair McArthur, Tagsys' vice president of technology and business development. "In designing good systems, every solution is not shoehorned into one frequency. It makes more sense to select the frequency depending on the application and the specific read environment and read requirements."
During the demonstration, Tagsys and Philips also simulated a checkout application. Six tagged bottles of shampoo were waved quickly by a scanner, the way a checkout person might scan an item. The system picked up the EPCs in less than half a second.
Philips plans to market the chip under its I-Code brand, but it is a completely new chip based on the Auto-ID Center's specification. Unlike other I-Code chips, it can be programmed only once. This minimizes the complexity of the circuitry, which helps keep the price of the chip low. (Actual pricing has not been released.) The tag also has low power requirements, which gives it a longer read range -- about 750 mm, or 2.5 feet, compare to a foot or less for many 13.56 tags.
Tagsys created some firmware, software stored permanently in the reader, to allow its reader to interrogate the EPC tags. The company showed off a fixed reader, but McArthur says it has the same capability on ultra-small protocol boards that could be used in handheld readers. He adds that Tagsys could have a 13.56 MHz EPC reader on the market soon, but Philips is not expected to make the chip commercially available until the middle of next year.
"In the whole Auto-ID Center arena, there is a lot of focus on the low-cost chip," says McArthur. "But as the customer base matures, there will be a recognition that that is only one element of the solution. Our contribution to this demonstration was to implement a robust hardware system with the EPC chip."
It is estimated that the market for RFID tags for item-level tracking in retail stores is more than 100 billion units per year.