RFID PORTAL SYSTEM WITH RFID TAGS HAVING VARIOUS READ RANGES

摘要

A system and method selectively reads radio frequency identification ("RFID") tags within an RFID interrogation zone. A portion of the RFID tags have a first operating range and a portion of the RFID tags have a second operating range that is different from the first operating range. Each RFID tag is programmed with an identifier associated with the operating range of the RFID tag. A first interrogation signal is transmitted which has sufficient power to activate RFID tags that are located within the RFID interrogation zone and have the first operating range. A response signal is received from each RFID tag capable of receiving the first interrogation signal. Each response signal indicates the identifier of the associated RFID tag. Each RFID tag that has an identifier associated with the first operating range is selected.