Patent ID: 8134452

Claim:
A method comprising: (a) selecting, by each of a plurality of radio frequency identification (RFID) tags, a time window within which to transmit; (b) sending a start signal from a RFID reader to the RFID tags, the start signal indicative of the start of a first time window; (c) transmitting a signal, by each of the RFID tags, in the respective time windows without receiving input from the RFID reader, wherein at least two RFID tags transmit the signal in the same time window; (d) for each of the RFID tags that transmitted the signal during the same time window, selecting a new time window and retransmitting the signal without receiving input from the RFID reader; and (e) repeating step (d) until none of the RFID tags transmit the signal in the same time window.