• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
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• pp.163-166
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• 2003

In recent years, there has been increased to access multimedia service through the Internet due to rise of the access speed. We suppose the co-existence of the various access networks in adjacent area in the future, such as wireless LAN, Bluetooth, and 3G Cellular So, the size of the cell will be smaller and the number of access point will be increased. In other words, the potable devices need the efficient mobility scheme due to move between cells frequently Currently, the several of the scheme, which is Cellular IP, HAWAII, Mobile IPv4 regional registration, and hierarchical Mobile IPv6, is suggested to support micro-mobility but Mobile IPv4 is standard scheme to support the mobility of the mobile node. MPLS, which forwards the packet through switching instead of routing using IP address, has begun to deploy in the internet backbone to increase the performance of mobility protocol. The integration of both MPLS and Mobile IP improves the scalability of the Mobile IP data forwarding process by leveraging on the features MPLS which are fast switching and high scalability. Moreover it abbreviates IP-in-IP tunneling between HA and FA. In this paper, we suggest efficient mobility scheme through integration of both MPLS and hierarchical Mobile IPv6.

• 한국통신학회논문지
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• 제29권8B호
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• pp.755-761
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• 2004

본 논문은 무선랜 기술을 활용한 초고속 무선인터넷 서비스에서 사용자 인증방식에 사용되는 프로토콜의 설계와 구현에 관한 것이다. IEEE 802.l1b를 기반으로 한 공중 무선랜 서비스는 최근 고속 무선 인터넷 접속 솔루션으로써 각광받고 있다. 공중 무선랜 환경에서는 특히 중앙 집중화된 인증방법과 향상된 보안대책이 필요하며 사용자 단말의 이동 시 로밍에 대한 보장이 요구된다. 본 논문에서는 IEEE 802.1x에 기반의 사용자 인증보안 기능을 설계하고 방법과 실제 임베디드 리눅스를 기반으로 한 무선랜 Access Point(AP)에서 구현하여 동작을 시험하였으며. 로밍 시 필요한 IAPP 절차에 대하여 검토하였다. 또한 업체를 통한 상용화를 진행하며, KT 네스팟 인증시스템과 정상적인 연동기능 및 관리기능이 동작함을 확인하였다.

• Journal of Communications and Networks
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• 제11권1호
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• pp.36-41
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• 2009

The IEEE 802.16 wireless metropolitan area network (WMAN) standard is designed to correct expensive communication costs in CDMA-based mobile communication systems and limited coverage problems in wireless LAN systems. Thus, the IEEE 802.16e standard can provide mobile high-speed packet access between mobile stations and the Internet service provider through the base station with cheap communication fees. To efficiently accommodate voice over IP (VoIP) services in IEEE 802.16 systems, an uplink quality of service packet-scheduling scheme is proposed, and its performance is evaluated with an NS-2 network simulator in this paper. Numerical results show that this proposed scheme can increase the system capacity by 100% more than in the unsolicited rand service (UGS) scheme and 30% more than the extended real-time polling service (ertPS) scheme, respectively.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2001년도 The Pacific Aisan Confrence On Intelligent Systems 2001
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• pp.198-201
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• 2001

Recently the wireless-internet has been spreading extensively. People are spending a large part of their time gaining access to information using a mobile device. With the rapid growth of on-line Electronic Commerce, the use of mobile devices creates a new paradigm that provides users with location-independent real time service. Although this new paradigm does have some advantages, limited process speed, low bandwidth, the low battery capacity of mobile devices, and a high rate of wireless network errors causes many overhead expenses during service time with the server. In this paper, we suggest an autonomous service delivery system, which provides mobile agent capability to users that cannot maintain a connection. We have developed the system based on java mobile agent technology. Using this system, we can provide more effective service to users when the user is sending requirements for service through a mobile device that has limited resources. Furthermore we can manage the contact server dynamically when new services are added.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1855-1858
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• 2002

A number of MPLS ATM systems have been proposed to increase the access speed of current routers, which only support the best-effort service. However, the MPLS ATM systems have to support the so-called differential service, which discriminates the applications according to the service class because they do not be satisfied the Internet users who use diverse applications. In this paper, to support this differential service a detailed forwarding procedure based on a LSP control method and an application-based marking algorithm is suggested. The LSP control method establishes several different LSPs for each FEC according to the service class and the application-based marking algorithm chooses a proper differential service depending on the application category. Also, a design scheme of forwarding engine, which can be easily implemented with a minimum modification of existing MPLS ATM systems is proposed. And, the best simulation result of high priority application category is gained when the proposed forwarding algorithm is comparedwithexistingalgorithms.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제13권2호
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• pp.110-118
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• 2007

초고속 인터넷의 발달로 수 많은 인터넷 사용자들이 웹사이트에 접속하여 인터넷서비스를 이용한다. 하지만 서비스와 정보를 이용하기 위해서는 많은 시간과 절차가 필요하다. 이러한 절차들은 원하는 인터넷 서비스를 받기 위해 필요한 작업이지만, 사용자들에게는 번거로운 일이다. 따라서, 사용자들의 웹 사용 패턴에 따라 편리하게 웹 서비스를 받기 위한 가상 포털 시스템을 본 논문에서 제안한다. 본 논문에서 제시하는 가상 포털 시스템은 사용자의 개인 컴퓨터를 마치 웹 서비스 제공 사이트처럼 가상화하여 개인에 맞는 맞춤 서비스를 사용자 스스로 정의할 수 있게 한다. 또한, 전용 브라우저를 복수 브라우저 장으로 만들어 네이비게이션 할 수 있는 기능을 제공하며, 웹 서비스를 이용하는 사용자들이 보다 신속하고 편리하게 사용할 수 있도록 개인화 된 가상포털 시스템을 구축하고 그 방법을 제시한다.

• 기술사
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• 제34권4호
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• pp.36-40
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• 2001

Multimedia service via satellite Is supported voice, data, Image and video signals. The representation case model of satellite multimedia are satellite TV. satellite Internet. In the early 1990s, satellite communication and broad casting services successfully expanded form C/Ku band to Ka band. The benefits of operation at Ka-band are greater bandwidth available to accommodate the increased demand for high-speed Information exchange. By the early years of the 21s1 century, millions of households worldwide with dual Ku / Ka-band dishes Satellite multimedia systems receive hundreds of TV channels, originating from around the world, and delivering entertainment, information and education. Many Ku-band satellites have been ordered, but few Ka-band systems are moving into production. So Ka-band systems are characterized that low-cost access to low and high peed, two-way voice, data, and video communications.

• 기술혁신학회지
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• 제7권2호
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• pp.459-479
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• 2004

As the high-speed internet access market steadily nears its maturity phase, growth is quickly tapering off and competition, intensifying. As a result telecommunications companies are at present faced with the urgent need to evolve away from a growth model based on continuous acquisition of new subscribers. The recent convergence of telecommunication and broadcasting has come about precisely at this transitional period in the telecommunications market, and is perceived by the industry both as a new business opportunity and as a threat. TV-based VOD(Video on Demand), for one, is able to attract new customers desiring multimedia services of superior quality and to lock-in existing customers. Meanwhile, the latest evolution in network development is brightening the market prospect for TV-based VOD. The service has now hit the market, deployed over VDSL networks - a next-generation high-speed internet - and advanced cable modem networks, delivering high-definition DVD-quality videos. TV-based VOD is a service whose deployment is closely linked to the evolution of subscriber networks. According to the forecast produced by the present study, based on the forecast on the post-ADSL market and a survey conducted on VOD, as post-ADSL subscribers increase from 1.53 million in 2003 to 4.44 million in 2004, and 9.87 million in 2006, the percentage of post-ADSL subscribers with intention to also subscribe to a VOD service is expected to rise from 16% to 34% in 2006. Accordingly, VOD subscribers are estimated to increase from 0.24 million in 2003 to 0.98 million in 2004 and to 3.35 million in 2006.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2005년도 춘계학술발표대회
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• pp.1397-1400
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• 2005

Multiprotocol Label Switching is an initiating IETF that integrated Layer2 information network links(bandwidth, latency, utilization) to Layer 3(IP) with a particular autonomous system(or ISP) in order to simplify and improve IP-packet exchange. MPLS gives network operators a grate deal of flexibility to divert and route traffic around link failures, congestion, and bottlenecks. The MPLS has advantages that will be able to solve existing problem of Network that ISP have had IP, QoS, Gigabit forwarding and traffic engineering. The purpose of this study is to measure Access-list and the capacities of PE Router that would operate as MPLS. Many ISP using MPLS service to handle high-speed internet traffic with apply to firewall in future.

• 대한전자공학회논문지TC
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• 제43권2호
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• pp.1-6
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• 2006

본 논문에서는 무선랜 환경에서 억세스 터미널(AT : Access Terminal)이 효과적으로 억세스 포인트(AP: Access Point)를 선택하기 위하여 로드발랜싱을 적용한 연결 설정 알고리듬을 제안한다. 본 논문에서 제안한 방법은 AP들과 AT의 연결 설정시 연결설정의뢰정보(AI: Association Information)로 도착 시간을 측정하고 AP의 부하 상태를 파악한 후 로드발랜싱을 적용한다. AT에서는 AP에 연결된 단말들의 트래픽량을 측정하여 부하가 적은 AP를 선택하여 설정하면 다수의 사용자가 동시에 사용하는 핫스팟 환경에서도 AP의 과도한 부하를 막을 수 있어 사용자 측면에서는 최대성능을 얻을 수 있으며, 망 사업자 측면에서는 효율적인 망 관리를 할 수 있다.