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

Abstract

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 2 Q-1(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.

Improving Efficiency of Passive RFID Tag Anti-Collision Protocol Using Dynamic Frame Adjustment and Optimal Splitting

“…The first issue requires that the emphasis be placed on reducing the number of collisions while the second one on scanning a group of known tags and identifying missing tags in the current round [ 21 , 22 ]. When the number of tags is equal to the number of slots in the initial frame, BTSA achieves the highest efficiency value of 0.43 [ 23 ], which is greater than the pure binary tree protocol [ 24 ] and the dynamic frame slotted ALOHA (Dynamic FSA) [ 12 ] with the same efficiency as the tree slotted ALOHA protocol (TSA) [ 18 , 25 ]. Different protocols have applied BTSA, such as Modified Q [ 26 ], estimation based FSA and binary selection [ 27 ] and adoptive binary splitting (ABS) [ 28 ].…”

“…Dynamic FSA [ 6 , 13 , 17 , 31 , 32 ] adjusts frame length with consecutive frames, which may include slots, to set up the identification process. Dynamic FSA has been merged with tree algorithms [ 15 , 18 , 23 , 26 , 33 ] to improve identification efficiency.…”