• Proceedings of the Korean Information Science Society Conference
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• 2000.04a
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• pp.259-261
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• 2000

B-ISDN의 가입자망 내에 도입된 광대역 액세스 망은 다양한 유형의 가입자들을 서비스 노드로 집선 또는 다중화하는 기능을 수행한다. 액세스 망의 ATM 연결을 동적으로 제어하기 위한 VB5.2 인터페이스의 프로토콜로는 B-ANCC가 있으며, 가입자망의 연결 및 호 처리를 위한 프로토콜로 DSS2, 국간 망에서는 B-ISUP이 표준화되어 있다. 전송 시스템의 각 구간마다 서로 다른 프로토콜들이 사용되므로 이들 프로토콜간의 연동 기능이 필요하며, 순차형 연동 방식과 병렬형 연동 방식이 제안되어 있다. 순차형 연동 방식은 VB5.2 인터페이스 프로토콜의 응답이 올 때까지 기다린 후, 국간 망 프로토콜의 연동을 진행하는 방식으로 동작하고, 병렬형 연동 방식은 VB5.2 인터페이스 프로토콜과 국간 망 프로토콜의 연동을 동시에 진행하는 방식을 사용한다. 본 논문에서는 ATM 연결등에 대한 순차형 및 병렬형 연동 방식의 시뮬레이션을 수행하여 연동 방식이 연결 설정 지연 및 완료비에 미치는 영향을 분석하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.6
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• pp.1503-1513
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• 1998

This paper is related to a performance analysis of B-NT system, which is essential compositional equipment of B-ISDN access network. A simulator enabling performance analysis according to the change of network configuration topology and the change of user traffic is developed in this study. The developed B-NT, system simulator consists of graphic user interface module, simulation program automatic generator module, and B-NT system model library module. As examples of the results of performance analysis using the simulator, end-to-end user cell transmission delay time, queueing delay time in each system, and cell loss rate in the head node switch are presented. The simulator developed in this paper can be utilized in determining the network topology of B-NT system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.2
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• pp.417-426
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• 1996

The end-to-end service clock recovery is a critical issue in providing constandt bit rate service through ATM network. The Synchronous Residual Time Stamp(SRTS) algorithm is used to recovery the source clock using time stamp of transmitter. In thispaper, we propose a Differential Residual Time Stamp (DRTS) transmission mechanism to effectively deliver the timing information of source clock in SRTS algorithm. The RTS transmission method simple in its hardware. From the results of field trial of DS3 rate interactive video communication system through B-ISDN testbed, it can be identified that DRTS method is superior to the RTS method.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.525-528
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• 2000

According to the development of B-ISDN on ATM network, the uses of Multimedia service is growing. Although ABR service uses the network resource most effectively because it is able to change the transfer rate, it is not used for multimedia service until recently. In this paper, we set priority queue and non-priority queue in the ATM switch and each queue has threshold so is can be adopted in different transfer rate method. We propose the real-time traffic transfer method over ABR service based on an effective traffic control method.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.6
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• pp.9-17
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• 1994

ATM (Asynchronous Transfer Mode) has a fixed-length packet transport scheme. It is one of the promising proposals in B-ISDN.Since the packet length is fixed, it can be potentially to perform the various service to users. In this paper, a queueing model for an ATM multip`exer loaded by CBR and ON/OFF input sources is considered, and the two-queue system which each type of input sources has a queue with a finite capacity is analyzed. The cell loss probabilities for a performance measures of ATM multiplexer are derived, and are also evaluated through numerical examples. As a result, the cell loss probability of ON/OFF sources for the queue size is rapidly decreased when the multiplexed number and burstiness are increased. Since cells of the CBR source have lower priority than cells of the ON/OFF source, cell loss probabilities of CBR sources are accordingly high independently of CBR cell arrival rate when the number of CBR sources is large.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1995.10a
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• pp.110-114
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• 1995

Subscriber-Unit(SU) method in apartment-housing is used as the plan for the Cable-TV(CATV) receiving facility. But it is decided to apply Notification NO.1994-18 of the Ministry of Communications regulations starting in march, 10.1994. In this study, a new plan of CATV-receiving facility according to the Notification NO.1994-18 is suggested, and it is designed to apply lone-wire from an amplifier box to a SU or another amplifier box. Proposed results adopt the Head End(HE) to introduc Integrated Service Digital Network(ISDN) and to raise added-value of apartment-housing.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.2
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• pp.132-141
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• 1992

The CCITT recommendation X.3, X.20, X.29 and X.25 protocols have been efficiently used in subscriber site for the purpose of using existing C DTE In the ISDN. The Packet Assem-bly /Disasembly (PAD) which covers these protocols can connect C_DTE to the PSDN. The number of C DTE connected to the PAI) Is dependent on the PAD performance. The design of the Traffic Generator (TG) S/W which can measure the PAD performance Is Introduced In this paper.

• Journal of the Korean Institute of Educational Facilities
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• v.3 no.1
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• pp.19-30
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• 1996

Integrated Services Digital Networks (ISDNs) and Broadband ISDN provide high speed data transmission capabilities and therefore, it is now possible to communicate with multimedia information including graphic, motion image, data and audio. Among several new services utilizing multimedia communication networks, distance education service which aims to overcome time and space restrictions between teachers and learners is now heavily focused in many countries. In this paper, several factors which affect to the effectiveness of distance education are surveyed and facilities for organizing distance education classrooms which utilize high speed multimedia communication network are studied in detail. Also, some points are suggested for organizing successful distance equation system based on the multimedia communication technology.

• Electronics and Telecommunications Trends
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• v.4 no.2
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• pp.22-42
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• 1989

세계 정보통신산업의 최근 큰 변화가 있었는데, 무역정책측면에서는 미국의 종합무역법확정 및 발효, 지역주의의 확대가 특징적으로 나타났으며 기술개발측면은 신기술 개발촉진, 국제간 생산 이전가속, 지적소유권 문제의 확산, 그리고 국제조직측면으로는 전기통신의 표준화, 신기술의 국제적 표준화, 국제 ISDN서비스 논의의 진전등이 환경변화 요인으로 지적되고 있다. 정보통신산업의 산업별 성장은 전체적으로 1987년이후 증가속도가 둔화되고 있으며, 특히 통신기기와 컴퓨터분야의 성장율이 저하되고 있다. 그러나 부품산업은 IC와 반도체의 수요확대에 힘입어 평균수준을 기록하고 있다. 국가별로 볼때 특징적인 것은 미국, 일본, 유럽 등 주요 선진국들에 비해 한국, 대만 등 신흥 공업국들의 성장속도가 빠르게 진행되고 있으며 시장점유율도 두드러지게 확대되고 있는 것으로 분석되었다.

• Electronics and Telecommunications Trends
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• v.8 no.1
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• pp.69-76
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• 1993

급증하는 이동 통신 수요를 충족시키고, 통신망의 ISDN(Integrated Services Digital Network)화에 부응하기 위해 현 애널로그 방식에 디지틀 방식의 도입, 전환이 불가피하다. 이에 따라 디지틀 이동통신의 한 방식으로 QUALCOMM사에 의해 제안된 CDMA(Code Division Multiple Access) 방식에 대한 표준화 작업이 TIA(Telecommunications Industry Association)의 소위원회 TR45.5 에 의해 진행되고 있다. 본 고에서는 CDMA 방식의 표준화를 위한 미국의 TIA, CTIA(Cellular Telecommunications Industry Association) 소위원회의 구성 및 역할 등에 관해, 그리고 위 소위원회의 요구에 의해 QUALCOMM사, Ericsson Radio System사, 및 SCS Mobilecomm사 등의 3개사가 제안한 방식들을 중심으로 CDMA 기술의 현황을 소개한다.