A new adaptive query tree on resolving RFID tag collision

A so-called tag-collision problem (or missed reads) in Radio Frequency Identification (RFID) system is the event that a reader cannot identify the tag if many tags respond to a reader at the same time. In this paper, we propose an adaptive query tree (AQT) protocols that combine the multiple M-ary trees. The large M reduces collisions, while the small M avoids the unnecessary inquiries. Our AQT protocol successfully decreases the identification time by reducing the collisions and the idle time simultaneously. Two variant modes were proposed in our AQT, the base AQT (BAQT) and the modified AQT (MAQT), designed for the random electronic product code (EPC) and the very similar EPC with the first half bits are identical. Simulation results reveal that the proposed BAQT and MAQT outperform the base query tree.