Persistent Q anti-collision algorithm for RFID

© Institution of Engineering and Technology.All Rights Reserved. In passive Radio Frequency Identification Systems (RFIDs), the interrogator should energise clients within range and use their backscattered replies to identify an inventory as quickly as possible. However, at the interrogator replies from two or more energised clients may collide and collided clients may not be identified. Therefore, collisions increase the number of timeslots needed to record an inventory. Reducing the number and frequency of collisions is an important and topical area research in RFID. Previously for passive Ultra High Frequency RFID the problem of collisions has been addressed using an ALOHA based protocol called the Q-Selection Algorithm. In this paper, a more efficient algorithm is presented that is shown to reduce the number of timeslots needed to record an inventory by approximately 30% when compared to the existing Q algorithm.