• Convergence Security Journal
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• v.11 no.1
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• pp.33-38
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• 2011

Current IEEE 802.11 standard is very vulnerable that between the AP and STA authentication and security mechanisms is widely known. Therefore, IEEE has proposed security architecture RSN (Robust Security Network) for 802.11. RSN is used the access control, authentication, and key management based on the IEEE 802.1X standard. In this paper, IEEE 802.1X or 802.11 a combination of several models proposed for the vulnerability, and session hijacking or MiM (Man-in the-Middle) attacks to respond, the authentication mechanism Was designed to the access control between the STA and the AP.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.6
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• pp.112-120
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• 2009

Both security enhancement in wireless and fast access for mobility are required to employ wireless LAN in ITS (Intelligent Transportation Systems). However, for the case of employing IEEE 802.11i security standard, it is known that the user authentication procedure of IEEE 802.1x and 4-way handshake procedure for stronger security enforcement may not be suitable for ITS due to its large delay. In this paper, we propose fast authentication method to resolve the above authentication delay problem, and verify its performance via simulation analysis.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2003.06a
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• pp.197-200
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• 2003

본 논문에서는 IEEE 802.11a 무선 LAN 용 CODEC 회로를 설계하고, VHDL 코딩과 FPGA에 의한 회로설계 검증에 관해 기술한다. IEEE 802.lla WLAN CODEC의 구조는 크게 데이터 보호를 위한 스크램블러/디스크램블러, 채널 에러에 대한 정보보호를 위한 Convolutional 부호기와 Viterbi 복호기로 구성된 채널 코덱, 그리고 연집에러를 랜덤 에러로 변화시키는 인터리버/디인터리버로 구성된다. 본 논문에서는, 이와 같은 CODEC의 각 부분을 하드웨어로 구현하기 위한 새로운 회로구성을 제안하고, 그 성능을 VHDL 코딩에 의한 시뮬레이션과 FPGA에 의한 하드웨어 검증 결과를 제시한다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2007.11a
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• pp.330-340
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• 2007

IEEE 802.11 wireless LANs employ the backoff algorithm to avoid contentions among STAs when two or more STAs attempt to transmit their data frames simultaneously. The MAC efficiency can be improved if the CW values are adaptively changed according to the channel state of IEEE 802.11 wireless LANs. In this paper, we propose a dynamic contention window control algorithm using the genetic algorithm to improve the MAC throughput of IEEE 802.11 wireless LANs.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9A
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• pp.1075-1082
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• 2004

Wireless LAN is a rather mature communication technology connecting mobile terminals. IEEE 802.11 is a representative protocol among Wireless LAN technologies. The basic medium access control (MAC) mechanism of IEEE 802.11 is called distnbuted coordination function (DCF). DCF shows poor throughput and high drop rate as the number of stations and offered traffic load increase. In this paper we propose an effective mechanism using dynamic mimmum contention window(CWmin) in wireless LAN~ and show that performance improves via simulations. Proposed dynamic CWmin scheme exhibits superior performance as the number of stations and offered load grow. As, our proposed scheme is expected to be more effective in highly densed wireless LAN environment.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.121-124
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• 2002

The IEEE 802.lla PLCP H/W for Processing efficiently control message between MAC and PHY is designed. Slate machine and clock control according to rate is designed and timing diagram is verified on the FPGA simulation environment.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.06a
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• pp.80-88
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• 2002

휴대용 컴퓨터의 보급이 확산됨에 따라 이들을 장소에 상관없이 컴퓨터망에 연결시키는 수단으로 무선 LAN의 사용이 확산되고 있으나 무선 LAN 서비스는 전파라는 무선매체를 사용함으로써 정보도용의 가능성이 높으며 감시도 어렵다는 특징을 가지므로 정보보호가 요구된다. 본 논문에서는 IEEE 802.11 표준안 및 IEEE 802.lleS 초안에서 제시하는 무선 LAN의 정보보호기술인 ESN, WEP, AES 및 SMIB에 관하여 기술한다.

• Journal of Digital Convergence
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• v.11 no.12
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• pp.453-458
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• 2013

In a wireless LAN environment, security is the most important. Security of 802.11 standard has many vulnerabilities of the network attack. IEEE has created mechanisms to security for this vulnerability. But the vulnerabilities is characteristic of broadcast in the air in wireless LAN, it is more disclosure then other network environments. In a wireless LAN environment, it can be accessed to the wireless LAN after authentication. Authentication process is one of most important because of the first security step. However, in the authentication process is not mentioned in the method of reducing the disclosure maximum fundamental. Therefore, in this research, the vulnerability of 802.11 are presented and how to do de-authentication in 802.11.

• 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.

• Journal of Internet Computing and Services
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• v.7 no.1
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• pp.151-164
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• 2006

The DCF of IEEE 802.11 standard coordinates transmissions onto the shared communication channel based on CSMA/CA protocol. Currently, 802,11 is the most widely deployed wireless LAN standard. In this paper, for 802.11-based wireless LAN we propose a service differentiation scheme adopting different contention window sizes and retransmission schemes for two different types of data packets and we present a Markov model for the state of a given station under a finite load traffic condition. We then derive an algorithm to find the transmission probability and the throughput. The proposed model is validated through simulation under various system settings.