Abstract—One of the key problems that affect the data integrity of passive RFID systems is the collision among the tags. A popular anti-collision algorithm which dominates the standards in HF and UHF passive RFID systems is framed slotted Aloha (FSA) and some variations of FSA. Throughput of the RFID system which determines the performance/efficiency of the system is reduced rapidly when the number of tags inside the interrogation zone is increased. Using larger frame sizes is not always the solution. The best performance can be achieved when the slot number is equal to the tag number for FSA algorithm. In order to estimate the number of tags, a lot of work has been done. The existing algorithm about the tags estimation has been discussed in this paper. And an idle slot number based estimation algorithm is proposed. The idle slot number based estimation algorithm uses the idle slots in a frame. For performance analysis, the idle slot number based estimation algorithm was evaluated with the parameters of 128 slots to estimate the number of tags. The proposed method considers two situation, one is applied only 128 slots in a frame and all of them are used to estimate the number of tags; the other is applied the first 128 slots in a frame with 1024 slots frame. The results showed that the proposed algorithm can improve the efficiency of the number of RFID tag estimation and provide a reliable solution for cases with a high density of tags in the area.

Index Terms—Idle slots, tag estimation, FSA, RFID.

The authors are with the School of Transportation and Logistics, Southwest Jiaotong University, Chengdu, China 610031 (e-mail: xqzhang@gatech.edu).

 

Cite:Xiaoqiang Zhang, Tingting Chen, and Fangjie Hu, "RFID Tags Estimation through the Statistics Method for ALOHA," International Journal of Computer and Electrical Engineering vol. 6, no.3, pp. 259-262, 2014.