• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.5
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• pp.53-63
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• 2009

This paper is to develop WiMAX CPE(wireless AP) that can provides Wi-Fi terminal with wireless Internet service by connecting to Wibro wireless network. This AP aims to support WiBro in upstream interface basically, and Wi-Fi and 100M Ethernet interface in downstream. So, we has developed the equipment for business that wireless ISP can provide many Internet customers with wireless Internet service by using Wi-Fi terminal in subway, car, ship, and so on, and the equipment for users that a user can purchase and then install in person. For the latter, multiple Wi-Fi terminals that be registered in WiBro service can be connected to Internet simultaneously.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.4
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• pp.1012-1017
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• 2008

Recently, the use of wireless fan is increased by the development of wireless communication and convenience. Moreover, it makes an issue of security threat and vulnerability of wireless tan. Therefore, the IEEE established new standard such as 802.11i in 802.11 to supplement security vulnerability of wireless tan. But the security threat that does not solve, still remains. In this paper, we proposed that the location detection algorithm, that is used Kalman-Filter, Lateration and RSSI, and the mechanism that detects security status of AP and unauthorized AP by using beacon-frame of AP in building. Finally, we confirmed performance of proposed algorithm is good in comparison of established algorithm.

• Journal of the Korea Society of Computer and Information
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• v.15 no.11
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• pp.117-124
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• 2010

Appling centralized network management architecture SNMP(Simple Network Management Protocol) to wireless networks causes the network overhead, NAT(Network Address Translation) problem on AP, and performance degradation of mobile nodes. In this paper, we propose an integrated management scheme for wired and wireless networks using mobile agents in order to solve above problems. In our proposed scheme, SNMP is applied to manage wired networks and MAs of SNMP are implemented in APs or wireless nodes to manage wireless networks. In addition, we propose a method to reduce the redundant OID information within SNMP response messages. Through the analysis, we show that our proposal resolves the given problems and reduces the processing delay of the wireless nodes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.943-946
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• 2005

As a proposed standard for radio resource measurement, 802.11k aims to provide key client feedback to WLAN access points and switches. The proposed standard defines a series of measurement requests and reports that detail Layer 1 and Layer 2 client statistics. In this paper, we analyze handoff processing time, radio specrum usage and handoff coverage using this scheme in home-network inter APs handoff.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.1
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• pp.87-95
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• 2014

Under only authorized AP is allowable environment, rogue AP which is generated by a smartphone tethering can be a serious security breach. To solve rogue AP problem, this paper proposes classifying algorithm of Kernel Support Vector Machine using features of RTT data. Through our experiment, we can detect rogue AP from LTE mobile network.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.9
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• pp.1983-1989
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• 2012

The IEEE 802.1x standard provides an architectural framework which can be used various authentication methods. But, IEEE 802.1x also has vulnerabilities about the DoS(Denial of Service), the session hijacking and the MiM(Man in the Middle) attack due to caused by structural of authentication protocol. In this paper, we propose a WLAN system which can offer safety communication by complement of IEEE 802.1x vulnerabilities. The WLAN system accomplishes mutual authentications between authentication servers, clients and the AP using PKI and prevents an illegal user from intervening in communication to disguise oneself as a client, the AP or authentication servers. Also, we guarantee the safety of the communication by the Dynamic WEP key distribution between clients and the AP.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3440-3446
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• 2015

One of technologies that make it possible for users to enjoy always-on Internet service using potable devices does be Wifi. However, users frequently feel its connection is not stable or its speed becomes slow. On the other hand, users see multiple available Wifi access points exist often. In this paper, we present a smartphone application, called to WiSMax, that periodically changes its Wifi connection to the best one among available Wifi access points to maximize its speed. Experimental results show that WiSMax presents faster Internet connection than IEEE802.11 as much as about fifteen percent and higher signal strength than IEEE802.11 as much as about five dBm.

• Annual Conference of KIPS
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• 2003.11c
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• pp.2033-2036
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• 2003

최근에 공공장소에서의 보다 안정적이고 고속의 무선 인터넷 접속에 대한 욕구가 커지면서 무선랜에 대한 수요가 많아지고 있고, 유무선 사업자들은 무선랜 시장을 선점하기 위해서 서비스를 서두르고 있다. 이와 같은 무선랜환경에서 안전하게 사용자를 인증하고 서비스를 제공하기 위한 표준으로 802.1aa 와 802.11i 가 있다. 이와 같은 802.1aa 와 802.11i를 지원하는 액세스포인트를 위해서는 두 표준을 지원할 수 있는 라디우스 클라이언트가 필요하다. 본 논문에서는 위의 액세스포인트가 라디우스 프로토콜을 사용하여 무선단말 사용자를 인증시켜 주고 WEP(Wired Eaulvalent Privacy)을 위한 키를 교환할 수 있는 라디우스 클라이언트를 설계하고 구현하였다.

• Journal of KIISE:Information Networking
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• v.28 no.4
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• pp.527-539
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• 2001

The wireless asynchronous transfer mode (ATM) system has the advantage of providing the broadband services with various quality-of-service requirements to the mobile terminal efficiently by utilizing the ATM technology developed for the wired ATM system. The available bit rate (ABR) service among various ATM services utilizes the available bandwidth remaining in the ATM link, which allows the efficient bandwidth usage. During the handoff of the mobile terminal, however, the queue length in the access point (AP) which resides in the boundary of the wired ATM network and the wireless ATM network may increase abruptly. In this paper, we propose a scheme which prevents the buffer-overflow and buffer-underflow in the AP during the handoff of the wireless ABR connection in the wireless ATM system using binary feedback rate-based ABR traffic control. This scheme controls the source's cell generation rate during both handoff period and some time interval after the completion of the handoff procedure. The simulation results show that the proposed scheme prevents the buffer-overflow and buffer-underflow. The proposed scheme can contribute to increasing the throughput of the wireless ABR service during handoff by preventing the buffer overflow and underflow during handoff period.

• Annual Conference of KIPS
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• 2024.05a
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• pp.154-157
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• 2024

최근 무선랜은 증가하는 트래픽 수요와 사용자의 다양한 애플리케이션 요구사항을 충족하기 위해 표준 기술이 진화하고 있다. 상용화가 본격적으로 시작된 WiFi 7 표준은 더 낮은 지연 시간과 더 높은 스루풋을 달성하기 위해서 멀티링크 동작(Multi-Link Operation, MLO) 기능을 도입하였다. 멀티 링크 동작은 다른 주파수 대역이나 채널을 활용하여 동시에 데이터를 송수신하는 기술로서 스루풋은 증가하지만, 전력 소모량이 커지는 문제가 있다. 또한, 종래의 무선랜 표준 기술들은 대부분 저전력의 경량 단말에서만 에너지 절감을 고려해 왔으며, AP(Access Point)의 에너지 효율성은 고려하지 않았다. 따라서 본 논문에서는 멀티링크 동작을 지원하는 AP에서 에너지 효율을 개선하는 파워 세이빙 메커니즘을 제안한다. 실험 결과에 따르면, 스루풋을 높이기 위해 링크를 산발적으로 사용하는 종래의 방식 대비 제안하는 방식의 에너지 효율성이 최대 19.18% 개선되었다.