Patent ID: 7315522

Claim:
A method comprising the steps of: sending a first signal from an interrogator to a plurality of radio frequency identification (RFID) tags, the first signal including parameters that describe bit storage locations of memory and a bit string; each of the plurality of tags receiving the first signal and comparing the bit string against respective bits stored in the bit storage locations of memory of each respective tag to determine if the respective tag is a member of a selected tag group; each tag of the selected tag group independently picking a respective first random slot value from a first number of slot values in accordance with an arbitration scheme; and a first tag of the selected tag group backscattering a first reply to the interrogator, the first reply including a first random number independently generated by the first tag, the first tag replying in accordance with a first sequence determined at least in part by the respective first random slot value independently picked by each tag of the selected tag group.