In RFID system, when multiple tags transmit information in the same wireless channel simultaneously, data collisions usually occur which will reduce the identifying efficiency of RFID systems. To resolve this problem, several Dynamic Frame-Slotted ALOHA (DFSA) methods have been proposed. However, these methods are generally not capable of achieving expected performance when the number of tags is much larger or smaller than the initial frame size. Aiming to this problem, a Rapid DFSAI (RDFSAI) method was put forward based on the DFSA with interrupt (DFSAI) in this paper. Firstly, whether the frame size is adjusted or not is judged by comparing the system efficiency with the reference system efficiency. Secondly, the multiple factor of the frame size is determined by the ratio between the collision and empty slots, which leads to a seriels of different multiple factors or. As a result, the proposed RDFSAI elevates the adjustment speed of frame size and reduces the unnecessary empty and collision slots effectively. Simulation results indicate that the RDFSAI method appears better performance than the conventional methods even the tag number is increased up to 1600.
A Novel Cross Layer Anti-Collision Algorithm for Slotted ALOHA-Based UHF RFID Systems
