• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.6 s.324
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• pp.25-31
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• 2004

fireless LAN can offer high data rate communication between wireless terminals. In IEEE 802.11 wireless LAN, a basic service unit is called a Basic Service Set (BSS), which consists of one AP and more than one wireless terminals. Terminals far from the AP may not communicate with high data rate because signal strength is weakened as they move away from the AP. In this paper we propose a method to permit high speed data transmission by grouping terminals and by using part of wireless terminals as repeaters. We analyze the proposed and algorithm via simulations. Our proposed grouping mechanism is shown to be an effective way to increase the distance for high rate transmission.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.4
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• pp.753-757
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• 2005

Wireless LAN was developed by alternative of LAN and because establishment was easy, have used into special field and special expenditure. Recently, Standard and a technology developed by leaps and bounds. Present is used into purpose of the Building to Building or wide connection etc. and relay of the high speed Internet and usage of picture communication that require multimedia band width. Specially, campus wireless LAM is thought that must secure radius $100\;\~\;200\;m$ dimension at the minimum 10Mbps speed as Internet transit trunk. But, there is difference as degressive here. In this paper, wireless LAN measured for effectiveness proof as Internet transit trunk in actuality utilization environment. Proved that should compose IEEE802.11b as AP more than minimum 3 when compose network to base as measuring result. Hereafter, there is the purpose that achieve performance evaluation of wireless UM in marine environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.425-428
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• 2002

To understand and forecast the wireless internet market in Korea, we will analyse the network externalities in wireless internet market into communication network externalities and hardware/software network externalities. The wireless market has two competing streams, one is mobile internet and the other is wireless fan internet. Both are characterized by strong network externalities which lead to increasing return to stale. Mobile internet is supposed more suitable for communication and WLAN for data. However these two system will compete in some area, and the critical factor to deride the winner is supposed to be the network externalities as in so many other high-tech industries had showed.

• Journal of Internet Computing and Services
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• v.8 no.1
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• pp.15-23
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• 2007

Wireless LAN (IEEE 802.11) uses traditional TCP for reliable data transmission, But it brings the unintentional packet loss which is not congestion loss caused by handoff, interference, and fading in wireless LAN. In wireless LAN, TCP experiences performance degradation because it consumes that the cause of packet loss is congestion, and it decrease the sending rate by activating congestion control algorithm. This paper analyzes that correlation of throughput and buffer size for wireless buffer tuning. We find MBT (Maximum Buffer Threshold) which does not increase the throughput through the analysis, For calculation of MBT, we experiment the throughput by using high volume music data which is creased by real-time performance of piano. The experiment results is shown that buffer tuing based on MBT shows 20.3%, 21.4%, and 45.4% throughput improvement under 5ms RTT, 10ms RTT, and 20ms RTT, respectively, comparing with the throughput of operation system default buffer size, In addition, we describe that The setting of TCP buffer size by exceeding MBT does not have an effect on the performance of TCP.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.3
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• pp.50-63
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• 2004

휴대인터넷은 새로운 고속 무선 데이터 서비스로서 초기 시장 진입 시 기존의 서비스와의 경쟁이 불가피할 것으로 보인다. 이러한 경쟁적 요인의 완화와, 전역적 커버리지 확보를 위한 망 투자의 효율성등의 이유로 타 망과의 연동을 적극 검토하고 있다. 본 논문에서는 2,3 GHz대역에서 전용의 주파수 할당을 통해 고속의 무선 데이터 접속 서비스 제공을 목적으로 추진되고 있는 휴대인터넷과 기존의 공중 무선 랜 및 CDMA 패킷 데이터 망과의 연동과 관련 된 주요 이슈들을 설명한다. 이러한 이슈들에는 연동 서비스와 관련된 사업적 모델과 망 구조, BM 구현을 위한 가입/과금/인증 등의 소프트 인프라, 단말, 사용자 경험, 이동성 지원 등의 문제들이 포함된다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.3B
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• pp.174-180
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• 2012

As the number of a smart phone user over the world surprisingly grows and a wireless Internet market expands, service requirement of a mobile terminal is increasing. However, because there is no consideration of mobility in the early standard step, it is difficult to expect to improve the service performance in handover procedure. This paper proposes a PFMIPv6 handover scheme by using probe request message and authentication message and by using buffering scheme in IEEE 802.11. In addition, we simulated this proposal scheme and verified that the proposed handover scheme is improved in terms of handover delay, and average FTP throughput during the handover period.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.177-181
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• 2004

It is as research about embodiment of MAC algorithm that is point of wireless LAN technology that is radio skill that is receiving present head of a family footlights, and embodied MAC that is algorithm that control modem Rf and host interface to level that existent common use radio AP and send-receive of high speed are available that embody function that is presented to IEEE 802.11 specs using H/W and S/W. When embody actually, tested module that embody actually using module modem and RF part because test is impossible after have common use product. Also, module that embody actually designed, and is expected to be utilized in radio LAN system construction of high speed late considering CRC and FCS ewer on channel.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.2A
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• pp.128-139
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• 2004

As the Internet usage grows, people want to access the Internet while they are moving. To satisfy this requirement economically, IEEE 802.11 Wireless LANs(WLANs) are rapidly deployed. In order to support mobility, WLANs must provide smooth handoff mechanism. Recent studies show, however, handoff delay of WLANs exceeds 300ms, most of which is due to slow scanning mechanism finding a new AP. With this handoff delay, current WLANs is not suitable to provide seamless realtime interactive services such as VoIP sevice. In this paper, we analyze the current handoff method of IEEE 802.11 and we propose a new handoff algorithm which can decrease time needed for searching a new AP and thus reduce overall handoff time. We show by simulation that the proposed algorithm has shorter handoff delay than current handoff method.

• 한국ITS학회:학술대회논문집
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• v.2007 no.10
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• pp.1-6
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• 2007

• Proceedings of the Korea Multimedia Society Conference
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• 2012.05a
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• pp.127-128
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• 2012

본 논문에서는 무선 네트워크 환경에서 윈도우즈 데스크톱의 원격 접속이 가능한 안드로이드 원격제어 시스템을 제안한다. 제안한 시스템은 비트맵 데이터 고속 디코딩, 자체 업데이트 모듈, 터치 이벤트 제어 모듈로 구성되어 있으며, 안드로이드 단말기에서 데스크톱 제어를 가능하게 한다. 무선랜 환경(802.11n)에서 성능 분석한 결과 연결 및 인증에 소요되는 시간은 1초 이내이며, 이벤트 반응 속도 및 비트맵 드로잉 처리 속도는 기존 데스크톱 원격접속 환경과 비교하여 약 25% 이상 빠른 성능을 보인다. 따라서 본 논문에서 제안한 시스템은 무선랜 기반 어플리케이션 및 단말의 원격제어 솔루션으로 매우 적합하다 할 수 있다.