Patent ID: 7612672

Claim:
A tag identification method in REID systems including a reader and a plurality of tags, the method comprising the steps of: (a) forming a temporary ID for each of the tags; (b) comparing an inquiry of the reader with a portion of the temporary ID in each tag when receiving the inquiry from the reader; (c) if the inquiry and the portion of the temporary ID are identical to each other, transmitting a remainder of the temporary ID in each tag to the reader; (d) if a collision occurs in the step (c), generating new inquiries for storing them in the reader; (e) if there is no collision in the step (c), transmitting an ACK signal to each tag whose temporary ID is identified to receive its real tag ID therefrom; and (f) repeating the steps (b) to (e) until there is no inquiry in the reader, wherein, in step (d), in case the tag responds with only a last bit of its temporary ID after step (c), the reader identifies two temporary IDs if there is any collision.