A new collision resolution protocol for mobile RFID tags

Radio frequency identification (RFID) systems have been widely deployed for inventory management, personal identification, and asset tracking. In such environments, RFID tags frequently move in and out of a reader´s interrogation zone. Consequently, it is necessary for a reader to keep track of all tags in its interrogation zone in a periodic manner. This requirement not only increases workload of a reader but also generates large amount of traffic from a reader to a management server. In this paper, we propose a selective tag identification protocol which has two sub-frames: an identification frame and an access frame. The proposed protocol improves RFID tag identification performance by introducing a frame counter that enables readers to discriminate newly arriving tags and leaving tags. In addition, simulation results show that the proposed protocol reduces the amount of traffic from a reader to a management server by updating only the changes in tag population.