• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.237-240
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• 2000

In this paper, we design the system that support data rate of 6Mbps(BPSK), 12Mbps(QPSK), 24Mbps(16-QAM) with OFDM, and the performance of this system analyze in the indoor channel when BER is 10$\^$-3/. In this simulation, first, we analyze performance of the system with and without channel coding. As the result, the coding gain of each system is 2㏈, 1.6㏈, 2㏈ when BER is 10$\^$-3/ Second, In the case of 16-QAM/OFDM, The effect of soft decision channel decoding method improve 2㏈ than hard decision when BER is 10$\^$-3/.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.208-210
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• 2009

Currently, Wireless LAN(WLAN) service is widely deployed to provide high speed wireless Internet access through the mobile stations such as notebook and PDA. To provide enhanced security and user access control in the public WLAN area, WLAN access points should have the capability of IEEE 802.1x-based user authentication and authorization functionality. In this paper, we provide a brief understanding of IEEE 802.1x standards and related protocols like EAPOL(Extended Authentication Protocol Over LAN), EAP, RADIUS and describe how the IEEE 802.1x is designed and implemented in our embedded linux-based WLAN AP which is named i-WiNG. (Intelligent Wireless Internet Gateway). For the network security and user authenti -cation purposes, a supplicant who wants to access Internet should be authorized to access the AP port using the EAPOL.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.50-52
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• 2001

반도체 장비간 통신의 표준인 SECS(SEMI Equipment Communication Standard)는 반도체 제조 업체에서 많이 사용되고 있다. SECS-I의 단점을 보완하기 위해 제안된 HSMS (High-speed SECS Message Services)는, TCP/IP를 지원하고 SECS-I에 비해 통신 속도가 높다. 사용자는 HSMS를 이용하여 LAN을 통한 장비 제어 및 모니터링이 가능하게 되었다. 그러나, 네트워크의 확장에 대한 관심 고조로 기존의 제한된 영역의 네트워크 구성에 대한 변화가 필요하게 되었다. 또한 사용자가 항상 LAN의 범위 내에서 장비 모니터링 및 제어하기에는 위치적 제약이 많다. 그렇지만 HSMS는 Web을 통한 데이터 전송 요구를 수용하지 못하고 있다. 따라서 SECS-II message가 Web을 통해 전송될 수 있는 새로운 포맷이 필요하다. 본 논문에서는, 구조화된 데이터를 정의하기 유리한 마크업 언어인 XML을 이용하여, SECS-II message를 Web으로 전송할 수 있는 포맷을 정의하고 이를 구현한다.

• Journal of Digital Convergence
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• v.1 no.1
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• pp.235-253
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• 2003

In this research, we have developed a model that can explain the potential customer's needs for the potable Internet service, a concept with 'QoS guaranteed lower-price high speed mobile Internet service. Based on the developed model, we have also derived some empirical implications for the business firms interest in the potable Internet market. The developed model is incorporating a survey result, answering of potential customer's attitude for the portable Internet service, from the subscribers to the Internet service, wireless LAN service, and mobile Internet service. As a result, we have found that a very innovative group, such as wireless LAN users and 20's age group using mobile Internet service, could be the most attractive market segment. Moreover, the aspects of the service coverage and the price competitiveness at the service launching stage could be the most critical success factors for the portable Internet service.

• The KIPS Transactions:PartA
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• v.11A no.3
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• pp.109-114
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• 2004

Increasing popularity of WLAN and advancement of WPAN allow user to connect to the Internet easily today. The increasing of number of networking mobile device such as laptop and PDA requires computing devices to share high speed Internet line or work on networks in most cases. This has stimulated the demand of access point that supports multiple network interfaces. This paper describes the process of design, implementation and test of the wired/wireless integrated access point that supports multiple network interfaces such as wired LAN, wireless LAN, Bluetooth, and Broadband network. We designed and developed the hardware system and protocol software to integrate heterogeneous network. The system has shown compatibility with standard specification and good performance through testing with various network devices.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.380-382
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• 2001

This paper presents the implementation of IEEE 802.11 Medium Access Control and Physical Layer Protocol that can be applied to wireless LAN system. We have used PRISM2 chipsets from Intersil to build the baseband, IF, and RF parts. DSSS(Direct Sequence Spread Spectrum) physical layer at 2.4GHz ISM band is adopted in the hardware prototype. To meet the high-speed requirement of physical layer, we have designed the MAC protocol layer with embedded firmware and FPGA. The prototype board is shown to be able to support the physical layer of 5GHz and 600Hz wireless LAN systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.8B
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• pp.755-761
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• 2004

Currently, Wireless LAN(WLAN) service is widely deployed to provide high speed wireless Internet access through the mobile stations such as notebook and PDA. To provide enhanced security and user access control in the public WLAN area, WLAM access points should have the capability of IEEE 802.1x-based user authentication and authorization functionality. In this paper, we provide a brief understanding of IEEE 802. 1x standards and related protocols likeEAPoL(Extended Authentication Protocol Over LAN), EAP, RADIUS and describe how the IEEE 802.1x is designed and implemented in our embedded linux-based WLAN AP which is named i-WiNG.(Intelligent Wireless Internet Gateway).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.583-586
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• 2004

In this paper, we have analyzed the performance of synchronization of CCK(Complementary Code Keying) modulation scheme used for IEEE 802.11g wireless LAM system supporting 54 Mbps of high speed data rate over 2.4 GHz. At receiver, the clock frequency offset is caused by noise or fading. This frequency error occurs the offset of clock timing and causes ISI. Therefore the tracking is required to reduce the clock timing offset. The DLL(Delay Lock Loop), asychronization mode, performing tacking the clock is used for the simulation. The simulation result shows jitter variance and BER performance in the AWGN and multipath fading channel environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.12C
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• pp.1258-1267
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• 2003

As the need for stable and high speed wireless Internet service Brows, the wireless LAN service provider hurries to preempt wireless LAN service market. IAPP(InterAccess Point protocol) is defined to be able to provide a secure handoff mechanism of wireless LAN terminal information between AP(Access Point)s, and the related IEEE standard is IEEE 802.11f. For the secure handoff of wireless LAN terminal, it is necessary to transfer terminal's authentication & accounting information securely from old AP to new AP IEEE 802.11f recommends RADIUS server as IAPP server which authenticates AP and provides information for secure channel between APs. This paper proposes IAPP server using Diameter protocol to overcome the limit of RADIUS sewer, and describes about the interaction between server components and integration method with the current IAPP client system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.269-272
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• 2011

Recently, all areas of IT has been rapidly in land. As a result, the location is very important in everyday life. But in ship are limits network with communication Equipment and service. As a result, be far removed from information age. Currently, ship is connected with the outside world via satellite on the voyage. But, because high billing, ship is possible data transfer using low speed bandwidth. Because ship is not possible using LAN, only limit ship's crew some use internet in limited space. So, ship is required construction of the network. In this paper, because composition of basic IT environment with information need of crew and customer from ship to cruises, there construct LAN in ship and propose network design for network of ship.