• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.3
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• pp.45-55
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• 2003

Wireless LAM has the advantage of extension, flexibility and easiness of installation and maintenance. However, due to the characteristics of wireless media, it is vulnerable to security attacks. PKI(Public Key Infrastructure) is estimated to be a good solution offering security function to wireless LAM including global roaming. It offers high security functions as authentication confidentiality and digital signature while it generates big overheads such as CRL search and certificate verification. The overheads can not be avoided during the initial authentication. However, when we consider the case of handoff, it can be minimized through the fast handoff. In this paper, we design a fast handoff authentication mechanism based on PKI in the wireless LAM and analyze the performance of the scheme.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.5
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• pp.879-886
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• 2006

In this paper, we proposed an advanced authentication structure for reducing the certificate acquisition time which is one of the factors that should be improved in a conventional wireless PKI. A conventional key exchange method simply performs the key exchange setup step based on discrete algebraic subjects. But the mutual-authentication procedure of wireless PKI for reducing authentication time uses an elliptical curve for a key exchange setup step. We simulated and compared the authentication structure proposed by Sufatrio, K. Lam[4] and the our authentication structure in terms of the authentication time. Simulation results show that the proposed method reduces the authentication time comparing to the conventional wireless PKI authentication method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.5
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• pp.965-972
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• 2005

We propose a new resource management scheme, Distributed Channel Allocation Protocol (DCAP), for multimedia Ad Hoc Wireless LANs (AWLANS). This scheme implements a Qualify-of-Service (QoS) providing distributed resource management on the Orthogonal Frequency Division Multiplexing-Code Division Multiple Access (OFDM-CDMA) channel architecture. According to the performance evaluation results for MPEG traffic sources, DCAP can be a good choice of resource management scheme for AWLANs supporting multimedia services on the Broadband Wireless Access(BWA)-type physical layer.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.7
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• pp.1406-1414
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• 2003

This study presents structures and transporting methods of Wireless LAM. And an efficiency analysis for throughput of W level in various environments such as classrooms, assembly halls and offices is performed at this point of time that studies of 5㎓ Wireless LAN are formed actively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.8
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• pp.1644-1652
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• 2003

In this paper, we have analyzed that interference effect between wireless LAN(IEEE 802.11 a) and radar system in 5㎓ band. Recently, Korea frequency Authority is considering the frequency allocation of wireless LAN system about 5㎓ band that is previously used in radar system. The co­existence occurs interference problem between wireless LAN and radar system, so it is required to analyze the effect of co­channel interference. Accordingly, the frequency allocation could be predicted for wireless LAN system in 5㎓ band and the interference effect has been analyzed by simulation with the radar signal modeling. Simulation results which are presented by PER and EVM show that high SIR(20 ㏈) is required to achieve the target PER about 10­1.

• 한국ITS학회:학술대회논문집
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• 2003.11a
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• pp.197-201
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• 2003

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.6
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• pp.85-96
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• 2003

Wireless LAM in itself is vulnerable to eavesdropping and modification attack, and thus, IEEE 802.11i and IEEE 802. 1x/1aa have been defined to secure the wireless channel. These protocols accompanied by RADIUS and EAP-TLS provide users of wireless LAM with integrity and confidentiality services, and also they perform authentication and access control of wireless ports. In this paper, we suggest a method to implement accounting session using authentication session of IEEE 802. 1x and accounting state machine is designed with the accounting session. Also, we propose a key exchange mechanism to establish secure channel between stations and an access point. The mechanism is designed to be inter-operable with IEEE 802. 1aa.

• International Journal of Contents
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• v.1 no.1
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• pp.29-34
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• 2005

In this paper, we proposed an advanced authentication structure for reducing the certificate acquisition time which is one of the factors that should be improved in a conventional wireless PKI. A conventional key exchange method simply performs the key exchange setup step based on discrete algebraic subjects. But the mutual-authentication procedure of wireless PKI for reducing authentication time uses an elliptical curve for a key exchange setup step. We simulated and compared the authentication structure proposed by Sufatrio, K. Lam[4] and proposed authentication structure in terms of the authentication time. Simulation results show that the proposed method reduces the authentication time compared to the conventional wireless PKI authentication method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.12A
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• pp.1349-1355
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• 2004

In tile wireless communication networks although the modulation and demodulation structure with proposed BOWLIS algorithm is a little confusing but we certified that it is fit structure in fast operation processing and high speed wireless LAM system that is more strong on frequence and electro magnetic interference because it process the inputted data within 2.8Us that is faster 0.4Us than 3.2Us in standard form. Also we certified that in the sigtlt of consuming power it is better than pipe-lined structure because of reducing the processing step to 4.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.542-547
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• 2003

This paper proposes the method to develop information system for maintenance of urban transit using wireless LAM. Wireless LAN communication provides very useful method to maintain urban transit vehicle. We will use wireless LAN to transmit driving data, operational data and trace data from vehicle to wayside. And also we will use wireless LAN to refer various information concerning to work in real time. Proposed method may prevent loss of maintenance manpower and provide effective maintenance process.