Master-slave dual readers enhanced aloha anti-collision mechanism for dense active RFID

Active RFID is a popular technology in online measurement, remote monitoring, wireless tracking, fleet management etc. The communication algorithms widely used are based on a random access algorithm ALOHA, with which the data packets are transmitted in a random delay when collisions happen. However, collisions in ALOHA based algorithms are severe in dense active systems. In this paper, we propose a Master-Salve Dual Readers (MSDR) anti-collision mechanism. Multiple experiments were performed to identify multiple active tags within a reader´s interrogation range. Compared with the parallel dual readers (PPDR) mechanism and the single reader mechanism, the proposed MSDR reduces the rate of packets loss significantly.