An Enhanced Posterior Probability Anti-Collision Algorithm Based on Dynamic Frame Slotted ALOHA for EPCglobal Class1 Gen2

In a Radio Frequency Identification (RFID) System, collision between tags is one of the core problems that we must consider about. In general, a collision will occur when more than one tag communicates with the reader simultaneously, reducing the system efficiency. To solve this, dynamic frame slotted ALOHA (DFSA) is widely adopted nowadays, and as a variant of DFSA algorithm, Q-algorithm is accepted by the EPCglobal specifications for RFID air interface Class1 Gen2 protocol. Based on this, we provide a new algorithm called EPP-Q to adjust the parameter Q more accurate as well as maintain high system efficiency when tags are no more than 21(Q belongs to 0 to 15). The simulation provides an obvious improvement when EPP-Q is compared with other two mainstream algorithms, not only in system efficiency, but also in the quantity of time slots used.