• 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.

• 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.

• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.10A
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• pp.987-996
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• 2008

In this paper, the conventional anti-collision algorithms, such as Channel Monitoring algorithm and Pulse Protocol algorithm are analyzed. To decrease tag identification time, and increase system throughput and efficiency, we propose a new reader anti-collision algorithm, Pulse Protocol-based Hybrid Reader Anti-collision Algorithm, using Slot-occupied Probability under dense reader environment. The proposed algorithm uses Slot-occupied Probability to improve the performance of Pulse Protocol Algorithm. That is, A reader checks Slot-occupied Probability after generating random backoff time. If Slot-occupied Probability is greater than 0, it uses another new random backoff time to avoid reader collision. We also compare the performance of the proposed algorithm with those of Channel Monitoring and Pulse Protocol algorithms in respect of identification time system throughput, and system efficiency. Simulation results show that the proposed algorithm has an increment of 5% of identification time and system throughput as increasing the number of readers.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.4
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• pp.1005-1014
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• 2010

When reader collect tags, we found that they tend to get together to specific interface in Multi-Interface Multi-Channel 2.4GHz Active RFID system. To solve this problem, we designed the LP-Combind and AP-Balanced protocol for load distribution between interfaces, then verified its superiority of the performance through the simulation. There are three problems to implement designed protocols in hardware of firmware-level. first, tag selects randomly the channel of reader and reader need the method which can change the channel of tags. second, reader has the synchronization problem between reader and tag. third, reader has problem that MCU of reader have to operate simultaneously dual interface. To slove this problems, we designed the message and implemented method for tag channel change and the protocol in order to adjust synchronization between reader and tag, Therefore, we compared and analyzed the performance of protocols by experiment. If LP windows size is same, the performance of LP-Combined protocol and AP-Balanced protocol which lower collision probability by its load distribution is more outstanding than single interface protocol performance.

• 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.

• IEIE Transactions on Smart Processing and Computing
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• v.1 no.1
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• pp.65-71
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• 2012

Mobile RFID is a new application that uses a mobile phone as an RFID reader with wireless technology and provides a new valuable service to users by integrating RFID and ubiquitous sensor network infrastructures with mobile communication and wireless Internet. Whereas the mobile RFID system has many advantages, privacy violation problems on the reader side are very concerning to individuals and researchers. Unlike in regular RFID environments, where the communication channel between the server and reader is assumed to be secure, the communication channel between the backend server and the RFID reader in the mobile RFID system is not assumed to be safe. Therefore it has become necessary to devise a new communication protocol that secures the privacy of mobile RFID-enabled devices. Recently, Lo et al. proposed a mutual key agreement protocol that secures the authenticity and privacy of engaged mobile RFID readers by constructing a secure session key between the reader and server. However, this paper shows that this protocol does not meet all of the necessary security requirements. Therefore we developed an enhanced mutual key agreement protocol for mobile RFID-enabled devices that alleviates these concerns. We further show that our protocol can enhance data security and provide privacy protection for the reader in an unsecured mobile RFID environment, even in the presence of an active adversary.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.1
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• pp.143-151
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• 2011

When a real-time data transfer is not possible between a reader and a back-end server in the mobile environment, the reader should support a capability to search a certain tag without communicating with a back-end server. Some recent papers related to the mobile reader-based tag search protocol have addressed privacy concerns for the reader and the tags. However, to our best knowledge, there are no papers addressing the problem arising from reusing tag lists existed in the mobile reader. In other words, there arise a problem that a mobile reader which has lost an right to access to a specific tag is able to search that tag by reusing a tag list for searching a particular tag. If mobile reader having an unauthorized tag list, the mobile reader can reuse a particular tag list. Our protocol provides the enhanced secure tag lists preventing the reuse of the tag lists and an efficient tag search protocol based on dynamic identity in the mobile reader-based RFID environments.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.667-668
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• 2006

Radio Frequency Identification (RFID) is an automatic identification method, relying on storing and remotely retrieving data using devices called RFID tags or transponders. RFID systems is coming into increasing use in industry and logistics. This paper discuses implementation of multi-protocol RFID reader SoC. The SoC contains multi-protocol RFID RFID reader, CPU, UART, memory.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.954-955
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• 2012

Recently as increasing the use of mobile communication devices the use of mobile readers for recognition tag attached to objects is also increasing. Accordingly, meantime, that gives rise to the vulnerability of RFID systems between reader and tag security issues, as well as security issues between the reader and the back-end server will occur. In this paper between the reader and the back-end server to security vulnerabilities efficient authentication protocol using the hash function is proposed.