Enhanced Binary Search with Time-Divided Responses for Efficient RFID Tag Anti-Collision

RFID is a generic term for technologies which use RF waves to identify, track, or categorize any object. One of the research areas in RFID systems is a tag anti-collision protocol; how to reduce identification time with a given number of tags in the field of an RFID reader. There are two types of tag anti-collision protocols for RFID systems: tree based algorithms and slotted aloha based algorithms. Since the tree based tag anti-collision protocols achieve 100% read rate, we consider how to improve the performances of the tree based RFID tag anti- collision protocols. This paper proposes bi-slotted tree based tag anti-collision protocols, bi-slotted query tree algorithm (BSQTA) and bi-slotted collision tracking tree algorithm (BSCTTA), which reduce both prefix overhead and iteration overhead by time divided responses depending on whether the collided bit is ´0´ or ´1´. According to the simulation results, the bi-slotted tree based RFID tag anti-collision protocols require less time consumption for tag identification than the present tag anti-collision protocols.