An efficient RFID anticollision algorithm using early adjustment of frame length

This paper proposes a radio frequency identification (RFID) anticollision algorithm to enhance the read performance of the EPCglobal UHF Class-1 Generation-2 standard. Our algorithm is based on the mechanism of early adjustment of frame length, as well as dynamic framed slotted ALOHA. To reduce computation complexity, the proposed algorithm adopts a simple rule for a reader to determine when and how the early adjustment starts. Furthermore, the proposed method resorts to at most three examinations of whether the early adjustment should start in each read round. As compared with the algorithms of examining at every time slot, the proposed method can significantly reduce the number of examinations. The normalized throughput of our method can reach a value of up to 34.6%. The advantage of low computation complexity comes at the expense of only 1.4% degradation of throughput. Therefore, it is suitable for most RFID readers built with a capability-limited microprocessor.