Patent ID: 6104333
Filing Date: 2000-08-15
Classification: G01S,G06K,G07B

Abstract:
A wireless communications method comprising:providing an interrogator configured for transmitting and receiving RF communication data;providing a plurality of RF identification devices respectively including integrated circuitry configured for receiving RF communication data transmitted by the interrogator and responsive to said receiving generating for transmitting a reply back to the interrogator; andprior to the transmitting of the reply, respective RF identification devices delaying transmission of their respective replies to the interrogator for a determinable amount of time which is less than the amount of time required to transmit the reply, said delaying being initiated by the RF identification device responsive to RF communication data received from the interrogator, the amount of delay being different for different of the RF identification devices, wherein if there is a collision between replies from two RF identification devices, the collision can be more readily detected by the interrogator, using only a checksum analysis, than if there was no delay.