Novel modulo based Aloha anti-collision algorithm for RFID systems

RFID (Radio frequency Identification) has become an efficient way to identify, track and/or trace objects and people. Its importance has motivated scientists and researchers to examine the challenges that are slowing its expeditious deployment in various applications. RFID collision is a major challenge imposed by the wireless links shared among a reader and the many tags in the interrogation zone. In most proposed anti-collision algorithms, tags reply randomly to time slots chosen by the reader. Since two or more tags may choose the same slot, this Random Access (RA) causes garbled data at the reader side; therefore, the identification process fails. In this paper, we propose a new anti-collision algorithm that adopts a novel method for eliminating the theory of RA to enhance system efficiency and to reduce both the number of rounds between reader and tag and the number of collided/empty slots over existing algorithms. In this algorithm, tags use modulo function to choose tag owned time slot. Another advantage of this method is that the reader estimates the next frame size and compares it with the previously selected frame sizes that are saved in the reader to ensure there is no redundancy. The performance of the algorithm is simulated and compared with existent ALOHA family algorithms.