A Novel Anti-Collision Algorithm for EPC Gen2 RFID Systems

The tag collisions result in lengthy inventory processes and incorrect identification problems in a RFID system. EPCglobal Generation-2 (Gen2) specification proposes a framed slotted ALOHA based anti-collision protocol, named slot-count algorithm or Q-algorithm, for UHF passive RFID systems. In order to optimize the performance of the Q-algorithm, the frame size of the Q-algorithm determined by the value of slot-count (Q) needs to be updated iteratively according to the number of accessible tags. A Q selection scheme is addressed in the specification, in which the value of Q is updated slot-by-slot according to the status of the preceding received slot. This work proposes a Fast Slot-Count Selection (FSCS) algorithm that updates the value of Q based on stochastic analyses in the end of each frame. Simulation results validate that the FSCS algorithm can efficiently update the value of slot-count and hence accelerate inventory processes using EPC Gen2 UHF passive RFID systems.