How RFID works
Unlike barcodes, RFID tags rely on radio waves rather than light to communicate their information. That means line-of-sight is not required and many RFID tags can be read at the same time. RFID tags can also be read through many different materials, including cardboard and most plastics. Typically in warehousing applications the RFID Tag is applied to a Carton, Tote, Box, or Pallet. The RFID Tag can be linked to both a single item or an item set within the Carton, Tote, Box, or Pallet.
Most all RFID tags contain at least two parts. The first is an integrated circuit for storing and processing information, modulating and demodulating a radio-frequency (RF) signal, and could possibly perform other specialized functions. The second is an antenna for receiving and transmitting the signal. More advanced tags can have sensors and batteries attached to enhance their functionality and read range.
To read the tags, RFID readers use one or multiple antennas to emit radio signals that prompt all of the RFID tags within range to respond with their unique IDs in rapid sequence. The reader then passes this information on to be looked up in a local database to determine the product's identity. In many cases the unique ID stored on the tag is an Electronic Product Code (EPC). EPC numbers are passed to the EPC network which, in turn, will identify the product manufacturer, product type (SKU), and can provide updated tracking information.