An approach of adjusting frame size in anti-collision algorithm for active RFID system

Specific method which is used to adjust frame size is not given by the Dynamic Frame Slotted ALOHA algorithm in the ISO/IEC18000-7 air interface protocol. To solve this problem, an approach is proposed in this paper. The Slot Size is analyzed first. With the condition of determined Slot Size, the number of unidentified tags around the Reader after the initial collection round is estimated. The frame size will be adjusted according to this number. Analysis shows that the throughputs of active RFID system can be very close to the maximum theoretical value when the proposed mechanism is applied. Via MATLAB, for 100 tags, simulation results indicate that the throughputs of RFID system are steadily remained a high performance by using this approach.