• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.4
• /
• pp.807-812
• /
• 2015

In RFID system, when multiple tags respond simultaneously, a collision can occur. A method that solves this collision is referred as anti-collision algorithm. In 13.56MHz RFID system of Auto-ID center, STAC protocol is defined as an anti-collision algorithm for multiple tag reading. The PS algorithm divides the tags within the identification range of reader into smaller groups by increasing the transmission power incrementally and identifies them. In this paper, we propose a STAC/PS algorithm that the PS algorithm is applied in the STAC protocol. Through simulations, it is demonstrated that the collision rate for the proposed algorithm is about 50% lower than STAC protocol. Therefore, the STAC/PS algorithm can achieve faster tag identification speed compared with STAC protocol due to the low collision rate.

• Proceedings of the IEEK Conference
• /
• 2008.06a
• /
• pp.299-300
• /
• 2008

In this paper, we propose Adaptive Group Separation(AGS) algorithm for efficient RFID system. AGS algorithm determines the optimized initial prefix size m, and divides the group of ��$2^m$. A reader requests the group and searches the tag ID. If a tag collision occurred, reader adds a one bit, '0' or '1' at first bit of collision point. As a result, we observe that transmitted data bits and the recognition time are decreased.

• The KIPS Transactions:PartA
• /
• v.16A no.4
• /
• pp.289-298
• /
• 2009

Generally, RFID systems are composed of one reader and several passive tags, and share the single wireless channel. For this reason, collisions occurwhen more than two tags simultaneously respond to the reader's inquiry. To achieve this problem, many papers, such as QT[8], HCT[10], BSCTTA[2], and QT-BCS[9], have been proposed. In this paper, we propose the tree-based anti-collision algorithm using a bit change sensing unit (TABCS) based on BSCTTA algorithm. The proposed algorithm can identify bits returned from tags through bit change sensing unit, even if multi collisions occur. So, it rapidly generates the unique prefix to indentify each tag, and reduce the total of bits. As the result, the cost of identifying all tag IDs is relatively reduced as compared with existing algorithms. It is verified through simulations that the proposed algorithm surpass other existing algorithms.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.2
• /
• pp.287-292
• /
• 2007

In this paper, a QT_ecfi algorithm is proposed for identifying all the tags within the identification range. The proposed QT_ecfi algorithm revises the QT algorithm, which has a memoryless property. In the QT_ecfi algorithm, the tag will send the remaining bits of their identification codes when the query string matches the first bits of their identification codes. When the reader receives all the responses of the tags, it knows which bit is collided. If the collision occurs in the last bit, the reader can identify two tags simultaneously without further query. While the tags are sending their identification codes, if the reader detects a collision bit, it will send a signal to the tags to stop sending. According to the simulation results, the QT_ecfi algorithm outperforms the QT algorithm in terms of the number of queries and the number of response bits.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.46 no.5
• /
• pp.48-55
• /
• 2009

In this paper, We propose Adaptive Group Separation algorithm for efficient RFID system AGS algorithm determines the optimized initial prefix size j, and divides the group of. A reader requests the group and searches the tag ID. If a tag collision occurred, reader adds a one bit, '0' or '1' at first bit of collision point, As a result we observe that transmitted data bits and the recognition time are decreased. The proposed algorithms have been verified by computer simulation. The performance of the proposed anti-collision algorithm is evaluated in terms of the number of repetitions and the amount of transmission bits according to the in crease of the number of tags is 256. The AGS algorithm improve the number of repetitions by about 32.3% and reduce tile amount of the transmission bits by about 1/40 than slotted binary tree algorithm.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.16 no.6
• /
• pp.109-117
• /
• 2016

The most important mission of RFID reader is identify EPC (Electronic Product Code) of RFID tag of products that located within distinguishable range of RFID reader. RFID reader transmits query message to RFID tags through wireless channel and RFID tags send unique EPC to response its query message simultaneously. therefore tag collision occurred frequently. RFID tags collision resolution algorithm required to apply RFID technology to various industries. In this paper, we propose enhanced M-ary algorithm that collision bits location is used by not only RFID reader but also tags. the main feature of the proposed algorithm is that integrate multiple query message of M-ary QT algorithm to the single query message by analyze multiple response messages from tags. the simulation results show that the proposed algorithm give better performance than M-ary QT algorithm in terms of the number of query-response, identification efficiency and communication overhead.

• Journal of the Korea Society of Computer and Information
• /
• v.17 no.2
• /
• pp.207-214
• /
• 2012

This paper is to improve an identification ratio of tags by analyzing Slotted ALOHA, Dynamic Slotted ALOHA, Binary-tree and Query-tree and shortening the tag identification time in mobile RFID. Also, it enables the stable information transmission of tags by saving backscattering power of tags through shortening of identification time. As a result, this increases the available time of the battery and accessibility to a RFID service. For this, we proposed the energy-efficient tag anti-collision protocol for mobile RFID. The proposed scheme shows advanced result in identification time and collision counts. This scheme may be the first attempt for the mobile anti-collision.

• Journal of IKEEE
• /
• v.14 no.2
• /
• pp.24-32
• /
• 2010

Slotted-ALOHA and Binary-tree method are researched for the anti-collision for RFID system. However, it is required of the rapid recognition time for all tags and the reduction of the system complexity. In this paper. the hybrid anti-collision method is proposed to solve the problems. The RFID reader with the hybrid anti-collision method groups the tags with the number which makes the maximum system throughput, then it reads each group by slotted-ALOHA method. By the computer simulation results, it is found that the hybrid method improves the tag identification time and the system throughput together with the comparison to other anti-collision methods. Therefore, the proposed hybrid anti-collision method will enhance the RFID system performance.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.11
• /
• pp.2569-2574
• /
• 2013

In 13.56MHz RFID system of Auto-ID center, STAC protocol is defined as an anti-collision algorithm for multiple tag reading. In STAC protocol, the reader uses the tag number estimation scheme to determine the number of slots for the next reply round. If errors occur in the estimated number of tags, the identification performances will be degraded due to a lot of collision or idle slots. Therefore, in this paper, we propose an ERPB algorithm that the reader cancels the reply round when it experiences a series of collision or idle slots during the current round. The transmission probability control for the tag is also applied to the proposed algorithm. Through simulations, it is demonstrated that the collision rate for the proposed scheme is about 39% lower than STAC protocol. Therefore, the proposed scheme can achieve faster tag identification time compared with STAC protocol due to the low collision rate.

• Proceedings of the Korea Society of Information Technology Applications Conference
• /
• 2005.11a
• /
• pp.203-206
• /
• 2005

Recently, the RFID(Radio Frequency Identification) technology has gained significant attention. One of the performance issues in RFID systems is to resolve the tag collision among responses from RFID tags. In this paper, we proposed a new scheme for estimation of the number of tags in the reader filed. The scheme is used by anti-collision algorithm to identify multiple tags efficiently. And we also present the simulation result that shows the proposed scheme to estimate tags efficiently and also to improve the systems efficiency.