• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.10B
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• pp.1159-1167
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• 2011

In this paper, we proposed and implemented an EPCglobal Reader Manegement (RM) based management protocol. Using RFID Reader's management function, we could diagnose an active RFID Reader concretely which was impossible with only using Reader protocols and check the problem quickly when the RFID Reader is in failure. When diagnosing RFID Readers using the proposed RM based management protocol, we can check on their failure in stages and specifically, and can estimate range of failure. This helps RFID Reader's fast recovery, reduce loss of failure and improve QoS. We could get reader information with almost same overhead compared with the management message in LLRP. And we could get more information about RFID Reader's operation status.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.8B
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• pp.822-829
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• 2009

A reader protocol is an interface between a host and RFID readers. There are several standards for reader protocol such as EPCglobal Low Level Reader Protocol (LLRP) 1.0.1, EPCglobal Reader Protocol (RP) 1.1, and ISO/IEC 15961/15962. Unfortunately, these standards focus on the passive RFID system, and so they are not appropriate for the active RFID system. In this paper, we implemented an efficient reader protocol for the active RFID system, which is based on EPCglobal LLRP 1.0.1, but smoothing/filtering functions of EPCglobal RP 1.1 are added. This protocol is designed to configure air interface parameters for active RFID readers and tags. It can reduce the amount of data transfer between the reader and host by filtering function, and can improve the performance of tag collection by smoothing function. In addition, it can remove inefficiency caused by tag memory data change according to the standards of ISO/IEC 15961/15962. In the real-world environment, we evaluated the performance of our implemented reader protocol using one RFID reader and 45 tags.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.5
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• pp.501-509
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• 2010

In this paper, the interference avoidance performance of the RFID reader with the compressive receiver was analyzed. In the environment of the multiple dense readers operating, the recognition rates of the conventional RFID reader and the proposed RFID reader with the compressive receiver were measured and compared. The recognition rate of the proposed reader was improved more than 2.7 times compared to the conventional reader. Especially, in the environment of two proposed RFID readers operating simultaneously, little degradation of the recognition rate was observed.

• The Journal of the Korea Contents Association
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• v.9 no.10
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• pp.40-50
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• 2009

Incorrect deployment of RFID readers occurs reader-to-reader interferences in many applications using RFID technologies. Reader-to-reader interference occurs when a reader transmits a signal that interferes with the operation of another reader, thus preventing the second reader from communicating with tags in its interrogation zone. Interference detected by one reader and caused by another reader is referred to as a reader collision. In RFID systems, the reader collision problem is considered to be the bottleneck for the system throughput and reading efficiency. In this paper, we propose a novel RFID reader anti-collision algorithm based on evolutionary algorithm(EA). First, we analyze characteristics of RFID antennas and build database. Also, we propose EA encoding algorithm, fitness algorithm and genetic operators to deploy antennas efficiently. To show superiority of our proposed algorithm, we simulated our proposed algorithm. In the result, our proposed algorithm obtains 95.45% coverage rate and 10.29% interference rate after about 100 generations.

• The Journal of the Korea Contents Association
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• v.9 no.10
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• pp.67-74
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• 2009

Incorrect deployment of RFID readers occurs reader-to-reader interferences in many applications using RFID technologies. Reader-to-reader interference occurs when a reader transmits a signal that interferes with the operation of another reader, thus preventing the second reader from communicating with tags in its interrogation zone. Interference detected by one reader and caused by another reader is referred to as a reader collision. In RFID systems, the reader collision problem is considered to be the bottleneck for the system throughput and reading efficiency. In this paper, we propose a novel RFID reader anti-collision algorithm based on evolutionary algorithm(EA). First, we analyze characteristics of RFID antennas and build database. Also, we propose EA encoding algorithm, fitness algorithm and genetic operators to deploy antennas efficiently. To show superiority of our proposed algorithm, we simulated our proposed algorithm. In the result, our proposed algorithm obtains 95.45% coverage rate and 10.29% interference rate after about 100 generations.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.715-719
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• 2009

Incorrect deployment of RFID readers occurs reader-to-reader interferences in many applications using RFID technologies. Reader-to-reader interference occurs when a reader transmits a signal that interferes with the operation of another reader, thus preventing the second reader from communicating with tags in its interrogation zone. Interference detected by one reader and caused by another reader is referred to as a reader collision. In RFID systems, the reader collision problem is considered to be the bottleneck for the system throughput and reading efficiency. In this paper, we propose a novel RFID reader anti-collision algorithm based on evolutionary algorithm(EA). First, we analyze characteristics of RFID antennas and build database. Also, we propose EA encoding algorithm, fitness algorithm and genetic operators to deploy antennas efficiently. To show superiority of our proposed algorithm, we simulated our proposed algorithm. In the result, our proposed algorithm obtains 95.45% coverage rate and 10.29% interference rate after about 100 generations.

• The Journal of the Korea Contents Association
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• v.7 no.11
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• pp.102-110
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• 2007

In this paper, a portable RFID reader which operated in 900MHz UHF band is designed and fabricated and the characteristics of the manufactured portable RFID reader is analyzed through measurement. Analysis of measurements results is achieved based on EPC Class 0 standards that proposed by EPC Global. The proposed RFID reader communicate with tags about 11kbps speed, and have 20 dBm for its maximum RF output power. The proposed portable RFID reader can recognize maximum 68 tags per second, and when reader's output power is 20 dBms, maximum recognition distance is 30cm. And the total size of implemented RFID reader is $71mm{\times}55mm$, that is the maximum 90%, minimum 14% reduced size compared with marketed product.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.2 no.6
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• pp.299-311
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• 2008

The Radio Frequency IDentification (RFID) system is a contactless automatic identification system, which comprises readers and tags. In RFID systems, a reader collision occurs when there is interference in communication between one reader and the tags, due to the signals from other readers. The reader collision problem is considered as the fundamental problem affecting high density RFID reader installations. In this paper, we analyze the existing reader anti-collision algorithms. We also propose a pulse protocol-based reader anti-collision algorithm using slot occupied probability (SOP). The implementation of this improvement is simple, yet it effectively mitigates most reader collisions in dense reader mode, as shown in our simulation. That is, the proposed algorithm reduces the identification time, and increasesthe system throughput and system efficiency compared with the conventional reader anti-collision algorithms.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.10 s.352
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• pp.27-34
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• 2006

This paper has implemented a very small($1.4{\times}2.8[Cm^2]$) 13.56[MHz] RFID reader ensuring machine ID recognition correctly in a noise space of Tag-to-Reader within 3Cm. For operation of the RFID system, at first, this paper has designed the loop antenna of a reader and the fading model of back-scattering on microwave propagation following to 13.56[MHz] RFID Air Interface ISO/IEC specification. Secondly, this paper has proposed the automatically path selected RF switching circuit and the firmware operation relationship by measuring and analyzing the very small RFID RF issues. Finally, as a very small reader main body, this paper has shown the DSP board and software functions made for extraction of $1{\sim}2$ machine ID information and error prevention simultaneously with carrying of 13.56[MHz] RFID signals that the international standard specification ISO/IEC 18000-3 defined.

• 전자공학회논문지 IE
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• v.48 no.4
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• pp.40-46
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• 2011

In this paper, we introduce a hybrid RFID reader to recognize the pets. There is no the RFID reader to recognize a different types of frequency simultaneously. The RFID reader with 134.2 KHz has disadvantages with limited recognition radius and direction. The developed reader is dual-frequency RFID reader (134.2 KHz, 13.56 MHz) that is capable of identifying the pets with a different types of tags. The prototype model in the field test shows that the recognition coverage increases compared to the imported reader.