• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.989-993
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• 2009

Wireless LAN(WLAN) is a rather mature communication technology connecting mobile terminals. IEEE 802.11 is a representative protocol among WLAN technologies. With the rising popularity of delay-sensitive real-time multimedia applications(video, voice and data) in IEEE 802.11 wireless LAN, it is important to study the MAC layer delay performance of WLANs. In this paper, performance for packet delay that recently have been proposed schemes is analysed in wireless LAN and proved performance results via simulation.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.45-48
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• 1999

The demands of WLAN(Wireless Local Area Network) systems increase rapidly in whole society and this phenonenon has been expected that WLAN wi11 substitute for wired-LAN. The FHSS(Frequency Hopped Spread Spectrum) method using the WLAN is changed to the performance of Frequency synthesizer. In this paper, we proposed pipeline-accumulator using ring-counter method instead of constant accumulator that has demerits of size and power consumption. Designed DDFS generated operating frequency of 167MHz and maximum output frequency of 83.5MHz.

• Journal of Communications and Networks
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• v.7 no.2
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• pp.192-206
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• 2005

Integration of mobile networks and Internet has started with 2.5 generation of mobile cellular networks. Internet traffic is today dominant traffic type worldwide. The hanger for higher data rates needed for data traffic and new IP based services is essential in the development of future wireless networks. In such situation, even 3G with up to 2 Mbit/s has not provided data rates that are used by Internet users with fixed broadband dial-up or through wired local area networks. The solution to provide higher bit rates in wireless access network has been found in wireless LAN although initially it has been developed to extend wired LAN into wireless domain. In this paper, we propose and describe a solution created for interoperability between mobile cellular network and WLAN. The integration between two networks, cellular and WLAN, is performed on the authentication, authorization, and accounting, i.e., AAA side. For that purpose we developed WLAN access controller and WLAN AAA gateway, which provide gateway-type access control as well as charging and billing functionalities for the WLAN service. In the development process of these elements, we have considered current development stadium of all needed network entities and protocols. The provided solution provides cost-effective and easy-to-deploy PLMN-WLAN Internetworking scenario.

• 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.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.10
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• pp.2121-2128
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• 2009

The application range of IEEE 802.11 wireless LAN has rapidly expanding from campus, enterprise to the public network of Hot Spot area due to the advantages of easiness of construction, mobility of wireless client station, convenience of usage and so on. However the security of WLAN(Wireless LAN) is vulnerable inherently because of using RF as a medium, and so the dangers of infringement of personal information and inside data of enterprises have increased and wardriving attack searching for security vulnerability in wireless LAN has become more serious especially. In this paper, we find out the overview of various procedures and preparatory stages for wardriving attack against wireless LAN, and propose complementary methods to prevent information infringement accidents from wardriving attack in wireless LAN. For this purpose, we make an equipment which is suitable for wardriving in wireless LAN and show security vulnerability of AP(Access Point) operation in WLAN around Yangjae-Dong in Seoul as a result of using the equipment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.9
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• pp.821-828
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• 2012

Recently, in order to provide the mobile multimedia service cost-effectively, the user's demand has been greatly increasing to use wireless LAN (WLAN). But existing WLAN (Wireless LAN) is vulnerable to attack of outside, as users are connecting AP using Open Authentication. In this article, we have designed and implemented WLAN Information Sharing System using social network service (SNS) which is efficiently managing. WLAN secure key. A proposed WLAN Information Sharing System model has been proposed in which the social trust strength between people is employed for WLAN access control.

• Journal of Digital Contents Society
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• v.9 no.4
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• pp.679-686
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• 2008

Wireless LAN(WLAN) is a rather mature communication technology connecting mobile terminals. IEEE 802.11 is a representative protocol among WLAN technologies. With the rising popularity of delay-sensitive real-time multimedia applications(video, voice and data) in IEEE 802.11 wireless LAN, it is important to study the MAC layer delay performance of WLANs. In this paper, performance for packet delay model that recently have been proposed schemes is analysed in wireless LAN and proved performance results via simulation.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.217-219
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• 2001

WLAN은 다양한 정보와 자원을 공유할 수 있게 하는 LAN의 장점과, 제약 없는 연결성 제공이라는 편리성을 동시에 제공하고, 신뢰성 있는 data전송뿐만 아니라 유연성과 설치의 용이성을 장점으로 갖고 있다. 그러나 WLAN 이용하여 여러 어플리케이션을 사용할 때 제기되는 문제로 WLAN은 셀룰라 폰의 soft handover와 같은 mobility가 완전하게 지원되지 않으므로 WLAN 환경에서 VoIP 서비스 같은 실시간 서비스에 제약이 있다는 단점이 있다. 본 논문에서는 WLAN의 제약을 극복하기 위해 WLAN환경에서 이동단말의 이동성을 지원하기 위한 handover 방안을 제시하였다.

• Information and Communications Magazine
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• v.30 no.6
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• pp.20-25
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• 2013

본고에서는 1GHz 이하 주파수에서 동작하는 Wireless LAN(WLAN) 표준으로, IEEE 802.11ah PHY/MAC 표준 규격에 대해서 알아 본다. IEEE 802.11ah 표준은, Smart Grid, M2M, IoT 와 같이 실내, 실외에서 많은 수의 단말들을 최소한의 전력소모로 데이터 통신을 하기 위한 목적으로 개발되었다. WLAN의 서비스 범위가 1Km 이상으로 늘어나게 되면, 그 동안 WLAN 에서 심각하게 다루지 않았던 Hidden Node 문제가 단말의 전력 소모, throughput performance 을 결정하는 중요한 요소로 등장하게 된다. 특별히 IEEE 802.11ah 에서는, 많은 수의 단말들간에 Hidden Node 을 고려한 Restricted Access Window 라는 새로운 channel access 기법이 제안되었고, 이에 본 고에서는 IEEE 802.11ah 에 새롭게 지원되는 MAC 기능들에 대해 중점적으로 살펴 보도록 한다.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1944-1947
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• 2002

The importance of security in WLAN(Wireless LAN) service is very critical, so IEEE organization has made the IEEE 802.1x standard. The IEEE 802.1x standard uses the EAP as authentication protocol which requires AAA(Authentication, authorization, and Accounting) server for authentication & accounting. for the reliable and scalable AAA service, the Diameter protocol has more advanced characteristics than existing radius protocol. So the Diameter protocol can be used for WLAN service provider who has large scale WLAN system and a large number of subscriber. This paper proposes the design of Diameter AAA server for the authentication and accounting of WLAN system which is adopting IEEE 802.1x standard.