Unlike bar codes RFID does not require a line of sight. The one way transmission of data is established wirelessly between in RFID tag and it's reader. A tag reader for RFID can take a form of a fixed infrastructure reader or a handle reader, for data to be transferred,both tag and the reader need to be within a range. For passive RFID fixed reader can read up to hundred plus feet and hand held readers can read up to fifty plus feet. Active RFID read range can distance way beyond hundred plus feet.