• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.632-634
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• 2012

In order for the connection to the wireless network from the list of priorities of the wireless AP to AP profile automatic connection by selecting the preferred method to register a profile, which is determined at the time of the change, the user does not respond to the demands of the part. In this study, the frequency of the user's access in accordance with the wireless AP, and by creating a profile, the user needs to meet with regard to network access adaptive research.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1106-1111
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• 2010

Conventional traffic network in the urban city has been constructed and operated under systems to collect and transmit based on the roadside AP(Acess Point). But This paper has investigated the new traffic network based on smart station which combined the power network. Futhermore, the smart station can collect and transmit the variable informations and functions that supply the vehicle moving lines, informative collector service and center interoperation etc.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.11b
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• pp.807-810
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• 2003

현재 무선랜은 AP(Acess Point)간 이동시 2계층 로밍을 이용하여 이동성을 제공한다. 그러나 무선랜의 AP간 로밍은 같은 서브넷 내에서는 동일한 IP로 MAC Layer의 접속만을 변경하여 이동성을 제공할 수 있지만, 다른 서브넷으로 이동할 경우에는 DHCP를 이용하여 IP를 새로 할당 받아야 한다. 최근 Hotspot 등 무선랜이 활성화 되어감에 따라 서브넷간 이동시에도 IP 이동성 제공을 위해서는 무선랜에 Mobile IP 도입이 필요하다. 또한 무선 인터넷 사용자의 급증으로 차세대 인터넷 프로토콜로 주목받고 있는 IPv6를 이용하여 이동성을 제공하려는 연구가 활발히 진행되고 있다. 본 논문에서는 SIP 기반의 VoIP 단말기에 FMIPv6를 적용하여 VoIP의 서브넷 간이동성을 제공하기 위하여 핵심프로토콜인 FMIPv6 프로토콜과 SIP 프로토콜을 설계하였다.

• Journal of the Korea Society of Computer and Information
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• v.25 no.6
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• pp.9-15
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• 2020

In this paper, we propose a case that drone (unmanned aerial vehicle), one of the representative technologies of the 4th Industrial Revolution, threatens airport safety and privacy infringement, and describes a drone control system proposal to solve the problem. Unmanned aerial vehicle (Drone) is creating a serious problem recently, In Korea, on May 21, 19, according to the Jeju Regional Aviation Administration, drones flew over Jeju Jeongseok Airfield twice in the same month, causing problems in aircraft operation. In overseas cases, two drones near the runway of Gatwick International Airport in the UK There has been a disturbance in which the takeoff and landing of the aircraft flies for a while, and various problems have occurred, such as voyeuring the private life of an individual using a drone. This paper is equipped with an Acess Point transponder mounted on a drone (unmanned aerial vehicle), and unspecified many who want to receive flight information (coordinates, altitude, and obstacles) of the drone access the drone AP, receive and receive the flight information of the drone, and receive unspecified multiple Drone AP flight information is collected and collected to provide the information of the drone currently floating on one user interface screen. In addition, an AP transponder is proposed to operate a safe drone (unmanned aerial vehicle) and the drone's flight information is transmitted., To receive and collect and collect data.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.178-180
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• 2005

저렴한 비용, 매우 작은 파워 소비라 낮은 데이터 전송속도를 지원 하는 IEEE 802.15.4 LR-WPAN(Wireless Personal Area Network) 기술은 앞으로 다가올 유비쿼터스 시대의 핵심이라고 할 수 있다. 도래할 유비쿼터스 시대에는 댁내에 LR-WPAN 기술을 적용한 다양한 상품이 보급될 것이다. 그러나 LR-WPAN은 매우 낮은 전력 소비를 위해 네트워크 기능을 최소화 하였기 때문에 응용에 있어 LAN 또는 WLAN(Wireless Local Area Network)등 기존 네트워크와의 통신 및 보안이 아직 고려되지 않아 보완이 필요하다. 본 논문에서는 WLAN의 Station이 LR-WPAN을 보안적으로 안전하게 제어할 수 있도록 AP(Acess Point)와 WLAN의 Station 그리고 LR-WPAN의 PAN Coodinator 간의 새로운 Message와 Function를 정의하고, 다른 두 네트워크간의 효율적이고 보안이 유지되는 프레임 프로세싱 매커니즘을 제안한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.6
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• pp.1333-1340
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• 2015

IEEE 802.11 MAC(Media Access Control) defines DCF(Distributed Coordination Function) for data transmission control. BEB(Binary Exponential Backoff) algorithm of DCF has a problem that if the number of stations connected are over a certain threshold, it degrades network performance because of packet collisions caused from the minimum contention window size. To cope with this problem, we proposed a novel algorithm, named as VBS(Variable Backoff Stage) algorithm, which adjusts the rate of backoff stage increment depending on the number of stations associated with an AP(Access Point). Analytic model of proposed algorithm was derived and simulations on the BEB and the VBS algorithms have been conducted on the OFDM (Orthogonal Frequency Division Multiplexing) method. Simulation results showed that when the rate of backoff state increment was 5 and 10, the number of retransmission were reduced to 1/5 and 1/10 comparing to that of BEB, respectively. Our algorithm showed improvement of 19% and 18% in network utilization, respectively. Packet delay was reduced into 1/12.