Patent ID: 6995655

Claim:
A method of identifying RF tags, the method comprising: issuing a wireless command using a reader, requesting that RF tags identify themselves; illuminating a plurality of RF tags with a radio frequency field using the reader, the reader accepting responses during a predetermined timeframe which includes a plurality of timeslots; respective RF tags randomly selecting a radio frequency and a timeslot from a plurality of pre-defined radio frequencies and timeslots; respective RF tags issuing a wireless response to the command, including information identifying the tag, using the selected radio frequency and timeslot; receiving the wireless responses with the reader; issuing wireless acknowledgements from the reader to RF tags that have been successfully identified responsive to the receiving and at the end of the timeframe; and if any collision was detected, the reader issuing a command to cause unacknowledged RF tags to randomly select a radio frequency and timeslot for another response.