The study of the tag identification problem in RFID systems

• Main Authors: Chun-Yi Wang, 王鈞毅
• Other Authors: Chi-Chung Lee
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/58530513818133810872

碩士 === 中華大學 === 資訊管理學系(所) === 98 === This research performed two works on RFID tag identification – static tag identification and mobile tag identification. In the static tag identification, slotted ALOHA is the most common method to make the tag identification. Slotted ALOHA have two features. The first feature is that the optimal throughput of slotted ALOHA increased if the number of tags and the number of slots are equal. The second feature is that if the number of tags is small and the frame size is equal to the number of tags, the throughput increases as the number of tags decreases. However, most researchers have made little effort to explore the second feature to increase the throughputs of Slotted ALOHA. This research proposes a grouping based dynamic framed slotted ALOHA anti-collision method with fine groups (GB-DFSA) to fully utilize the two features to perform tag identification. This research compares the throughput of GB-DFSA with those of the other two methods – EDFSA with partition and DFSA. The results show that the throughput of GB-DFSA is 40% which is higher than EDFSA (38%) with partition and DFSA (31%). In the mobile tag identification, mobile tags arrive at or leave the reader’s field randomly. This research proposed an ALOHA based mobile tag anti-collision algorithm - Enhanced dynamic framed slotted ALOHA for mobile tags (MT-EDFSA). MT-EDFSA estimates the number of unidentified tags as the frame size to raise the throughput of tag identification. MT-EDFSA broadcasts the identification information to arrival tags at the beginning. Arrival tags use this identification information to select a slot randomly and respond its EPC code in the current read cycle. This research compares the service time of MT-EDFSA with those of the other methods – DFSA and MT-DFSA. The results show that the service time of the proposed method is lower than those of other methods under different arrival rates.