• Journal of information and communication convergence engineering
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• v.10 no.1
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• pp.33-39
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• 2012

In this paper, we compare the accuracy of most representative radio frequency identification (RFID) tag estimation functions in the context of minimizing RFID tag identification delay. Before the comparisons, we first evaluate the accuracy of Schoute's estimation function, which has been widely adopted in many RFID tag identification processes, and show that its accuracy actually depends on the number of tags to be identified and frame size L used for dynamic frame slotted Aloha cycles. Through computer simulations, we show how the accuracy of estimation functions is related to the actual tag read performance in terms of identification delay.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.434-437
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• 2006

Today, Hospital Information System that integrates ubiquitous technologies are introduced in limited basis due to problems like standardization and limits on medical use, where responsibilities lie, legal safeguard on transmission, invasion of privacy etc. Particularly, problems like absence of tag design suitable for medical environment, compatibility issue with previous medical information system. In order to solve such problems, we have designed medical tags for the first time that are consistent with future ubiquitous environment by deciding on medically suitable field with 96bit tag offered by EFC as its base. Second, improving on previous multi-tag recognizing crash prevention algorithm, we have designed a priority anti-collision algorithm that reflects priorities on the needs in medical environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.712-714
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• 2016

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 13.56MHz RFID system of Auto-ID center, STAC protocol is defined as an anti-collision algorithm for multiple tag reading. In this paper, we propose a STAC/PS algorithm that the PS algorithm is applied in the STAC protocol. The simulation results show that the STAC/PS algorithm can achieve faster tag identification speed compared with STAC protocol due to the low collision rate.

• ETRI Journal
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• v.30 no.3
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• pp.486-488
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• 2008

In this paper, a scheme to increase the throughput of RFID systems is presented, which considers the capture effect in the context of framed ALOHA protocol. Under the capture model in which the probability of one tag is identified successfully depending on the number of tags involved in the collision, two probabilistic methods for estimating the unknown number of tags are proposed. The first method is the maximum likelihood estimation method, and the second method is an approximate algorithm for reducing the computational time. The optimal frame size condition to maximize the system throughput by considering the capture effect is also presented.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3A
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• pp.360-367
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• 2006

In this paper, we designed a digital codec of an RFID tag for EPC global generation 2 class 1. There are a large number of studies on RRD standard and anti-collision algorithm but few studies on the design of digital parts of the RFID tag itself. For this reason, we studied and designed the digital codec hardware for EPC global generation 2 class 1 tag. The purpose of this paper is not to improve former studies but to present the hardware architecture, an estimation of hardware size and power consumption of digital part of the RFID tag. Results are synthesized using Synopsys with a 0.35um standard cell library. The hardware size is estimated to be 111640 equivalent inverters and dynamic power is estimated to be 10.4uW. It can be improved through full-custom design, but we designed using a standard cell library because it is faster and more efficient in the verification and the estimation of the design.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.7B
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• pp.448-454
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• 2007

This paper proposes an estimation method of number of tags which may be necessary in improving anti-collision performance for ALOHA-based RFID systems. In ALOHA-based anti-collision algorithms, since the performance of the multi tag identification can be improved by allocating the optimal slot size corresponding to the number of tags, it is needed to exactly estimate the number of tags. The proposed method uses the a priori knowledge of the relation between the expectation of the number of empty slots and the number of tags. After measuring the number of empty slots in one ROUND, we estimate the number of tags which corresponds to the expectation of the number of empty slots nearest to the measured one. Simulation results show that the proposed method is superior to conventional methods in terms of the estimation accuracy and the computational complexity.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.5
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• pp.33-39
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• 2010

In this paper, we propose an improved anti-collision algorithm. We have designed an anti-collision unit using this algorithm for the 18000-6 Type C Class 1 Generation 2 standard (Gen2). The Gen2 standard uses a Q-algorithm for incremental method on the Dynamic Slot-Aloha algorithm. It has basically enhanced performance over the Slot-Aloha algorithm. Unfortunately, there are several non-clarified parts: initial value. If an incorrect value is selected, it causes degradation in performance. To increase throughput and system efficiency, and to decrease tag identification time, we propose an improved anti-collision algorithm. prorosed Q algorithm has an increment of 5% of system efficiency and a decrement of 9% of tag identification time.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.6
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• pp.109-117
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• 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 Institute of Electronics Engineers of Korea TC
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• v.46 no.5
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• pp.48-55
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• 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.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.3
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• pp.561-566
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• 2011

In EPCglobal Class-1 Gen-2 RFID system, a slot-count selection algorithm has been proposed to determine the slot-count size depending on the status of reply slot. In the slot-count selection algorithm of Gen-2, the slot-count value is increased or decreased by the weight C, which is identical and independent of the slot status. It has an advantage that the algorithm is simple, but it is difficult to maintain an optimal slot-count size. Therefore, in this paper, we propose an adaptive slot-count selection algorithm, which applies the parameter C differently based on the result of tag replies. Through simulations, it is demonstrated that the collision rate for the proposed scheme is about 42% and 65% lower than the schemes proposed by Wang and Gen-2. Therefore, the adaptive slot-count selection algorithm achieves faster tag identification time compared with the existing algorithms due to the low collision rate.