• Title/Summary/Keyword: reader

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A Reader Anti-Collision Algorithm based on Hierarchical Structure for RFID Systems (RFID 시스템을 위한 계층적 구조 기반의 리더 충돌 방지 알고리즘)

  • Oh, Jung-Suk;Hwang, Jun-Ho;Kang, Yu-Chol;Lee, Jung-Hee;Yoo, Myung-Sik
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.10B
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    • pp.885-893
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    • 2008
  • In RFID system, reader collision happened when multiple readers try to read the tags at the same time. Because reader collision reduces tag recognition performance, it is required for RFID system to have reader anti-collision algorithm. In this paper, we propose reader anti-collision algorithm based on hierarchical structure, where a master reader controls the slave readers to avoid the reader collisions. It is verified through simulations that the proposed algorithm enhances the performance in terms of leader collision probability and tag reading time.

An Enhanced Genetic Algorithm for Reader Anti-collision in RFID System (RFID 시스템에서의 리더 충돌 방지를 위한 개선된 유전자 알고리즘)

  • Seo, Hyun-Sik;Lee, Chae-Woo
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.45 no.5
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    • pp.85-94
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    • 2008
  • When an RFID reader uses the same frequency or adjacent frequency with neighbor readers, the interference might occur. These interferences cause the RFID reader collision and errors during tag recognition. Therefore, the international standard for RFID and some papers proposed the methods to reduce the reader collision. The reader interference is closely related to the distance between the readers haying interference and used frequency band. In the previous RFID reader anti-collision algorithms, the location of readers inducing interference which is closely related to interference of readers is not considered. Only the reader collision is tried to reduce through frequency transfer after collisions occur or modification of frame size in relation to collision probability based a TDM(Time Division Multiplex). In this paper, the genetic algorithm using two-dimensional chromosome which reflect readers' location is proposed to prevent reader collision effectively. By executing evolutionary operation with two-dimensional chromosome, the location information having influence on reader interference can be used. The repair operation in the proposed algorithm makes all reader stably recognize their tags.

Analysis of Channel Collision Avoidance Performance of RFID Reader with Compressive Receiver (컴프레시브 수신기가 내장된 RFID 리더의 채널 충돌 회피 성능 분석)

  • Jo, Won-Sang;Park, Dong-Chul
    • 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.

A Study on the Band Shifted Ubiquitous-lD Reader Platform (Band Shifted Ubiquitous-ID Reader Platform 연구개발)

  • Park, Kyung-Hwan;Kim, Young-Kil
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.2
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    • pp.1045-1048
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    • 2005
  • This paper is for the design and implementation of the reader which can recognize the tag of the UHF band that we do not become internationally the standardization. Universal RFID Reader uses the software and specifies the class of UHF band. And then, it can recognize UHF band tags controlling the hardware.

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A Study on the RFID Reader using Multi-UHF band (UHF 대역 멀티밴드 RFID Reader 기술연구)

  • Park, Kyung-Hwan;Kim, Young-Kim;Cho, We-Duck;NGO, Dr.
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.67-69
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    • 2005
  • This paper is for the design and implementation of the reader which can recognize the tag of the band that we do not become internationally the standardization. RFID Reader uses the software and specifies the class of UHF band. And then, it can recognize UHF band tags controlling the hardware.

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The design of reader for contactless ID card system (비접촉 ID 카드 시스템을 위한 리더 설계)

  • 진인수;양경록;류형선;김양모
    • Proceedings of the IEEK Conference
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    • 2000.06e
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    • pp.199-202
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    • 2000
  • RFID (Radio Frequency Identification) is a technique which is used for identifying different types of objects and tracking people and animals. Passive RFID consists of reader, a passive tag. The reader transmit energy to a tag and read information back from tag. The tag is energized by a carrier frequency which is transmitted by the reader and transmit information back to the reader. In this paper, the circuit for read and write RFID system is presented. The presented RFID system adopts 125kHz carrier frequency, backscattering and PSK for communication method.

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Performance of Multiple Coordinators-based RFID Reader Protocol (다중 코디네이터를 이용한 RFID 리더 프로토콜 성능 분석)

  • Lee, Se-Hee;Yang, Hoon-Gee;Yang, Sung-Hyun;Kang, Bong-Soon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.10
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    • pp.2247-2256
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    • 2011
  • In this paper, we propose a coordinator-based reader protocol that can avoid reader collisions in a passive RFID system. In a proposed protocol, unlike conventional protocols that a reader itself selects its own slot randomly to communicate with tags such as DCS, Colorwave, a coordinator reader allocates an unused slot to a reader to participate in the network and sends a current slot number. A reader allocated a slot can communicate with tags. The proposed protocol can adaptively modified to apply for multiple coordinator readers environment in a wide area. This causes reader collision problem, but can be alleviated partly by applying the frequency planning. In this way, we verifies that a RFID system using the proposed protocol is three to five times better than existing systems through the simulation.

Portable RFID Reader for 900MHz Band (900MHz 대역용 휴대용 RFID 리더)

  • Kang, Bong-Soo;Kim, Heung-Soo
    • 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.

Design and Implementation of a R1000/R2000 based RFID Reader Which Supports the Low Level Reader Protocol (LLRP를 지원하는 R1000/R2000 겸용 RFID 리더)

  • Bae, Sung-Woo;Ryu, Won-Sang;Kwak, Ho-Gil;Joung, Sub-Myoung;Park, Jun-Seok;Seong, Yeong-Rak;Oh, Ha-Ryoung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.2B
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    • pp.279-286
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    • 2010
  • RFID reader protocol is an interface between RFID readers and higher (host) such as RFID middlewares and applications. At present, reader protocols provided by vendors are different from each other and there are compatibility problems in environment using heterogeneous readers. In this paper, to solve this problem, an RFID reader which supports LLRP(Low Level Reader Protocol), a well-known standard reader protocol presented by EPCglobal is designed and implemented. It is designed with two modules and supports various interfaces for easy adaptation to various applications. The LLRP protocol is implemented over a embedded LINUX multi-thread environment. It not only supports almost all properties of LLRP, and is designed with flexible hardware/software architecture to meet various requirements.

Implementation of a very small 13.56[MHz] RFID Reader ensuring machine ID recognition in a noise space within 3Cm (3Cm 이내의 잡음 공간 속 기계 ID 인식을 보장하는 초소형 13.56[MHz] RFID Reader의 구현)

  • Park, Seung-Chang;Kim, Dae-Jin
    • 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.