Wednesday, May 14, 2008

"WIRELESS: Testbed streamlines RFID development"

RFID tags flooding warehouses and product shelves tax current testing methods, which separately tune into each tag. To streamline testing while enabling rapid prototyping of new designs, Georgia Institute of Technology engineers have crafted a new test bed they say is capable of simultaneously testing hundreds of RFID tags while emulating the chip in a new tag design. RFID tags are used for everything from inventory management to toll collection to passport identification to tracking luggage. Most tags are passive, including a chip and an antenna that absorbs a radio signal to backscatter its identity to a nearby reader. The biggest problem with testing RFID tags is the sheer volume--warehouses and store shelves often contain hundreds of tags within range of a reader, many hidden behind other tags. When multiple tags are within range of a reader, the usual protocol is to interrogate the tag with the strongest signal, then put it to sleep and proceed on to the next strongest signal. That serial process can be time consuming. Instead, the Georgia Tech test bed uses an anti-collision system capable of transmitting multiple, unique signals. The system allows up to 256 tags to be interrogated simultaneously. Instead of requiring readers to be within about a foot of tags, the Georgia Tech test bed can communicate with RFID tags within 400 square feet of the tester. Along with collecting tag information, the system can also track their signal strength in real time.