• ETRI Journal
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• v.14 no.4
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• pp.43-55
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• 1992

본 고는 광대역 ISDN 의 전송방식인 ATM(Asynchronous Transfer Mode) 프로토콜의 설계 및 구현에 대하여 기술하였으며, 설계된 ATM 프로토콜은 그 기능을 검증하기 위하여, 광대역 ISDN 을 통하여 Ethernet LAN간 연결을 지원하는 LAN TA(Terminal Adaptor), DS3 급 CBR(Constant Bit Rate) 비디오 서비스를 위한 비디오 TA에 적용하였다. LAN TA 와 비디오 TA에 적용되는 ATM 프로토콜은 공통으로 사용할 수 있도록 모듈화하여 설계하였으며 물리계층의 전송 매체 부분은 최대 100Mbit/s 까지 전송속도를 수용할 수 있도록 고려하였다.

• Electronics and Telecommunications Trends
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• v.14 no.4 s.58
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• pp.129-130
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• 1999

N-ISDN의 대중화 및 활성화를 위해서 연구 개발한 회선 및 패킷 통신 기능을 지원하는 N-ISDN 접속용 PC 카드로서, NT(Network Terminator)및 TA(Terminal Adapter) 기능을 하며, PC에서 다중 통신이 가능하도록 한다. 음성 통화중 다양한 ISDN 서비스를 이용 가능하도록 하며, 64kbps로 인터넷 접속을 할 수 있다. 또한 전용선 없이 ISDN을 통해 64kbps로 패킷망에 접속하여 데이터 통신이 가능하도록 하는 등 협대역 ISDN 통신 기능을 지원한다.

• Journal of Biomedical Engineering Research
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• v.15 no.3
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• pp.317-324
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• 1994

This paper proposed a new method in the implementation of ISDN (integrated services digital network) LAPD (link access procedure on the D-channel) and LAPB (link access procedure on the B-channel) protocols. The proposed method in this paper implement ISDW LAPD protocol through multi-tasking operating system and adopt a kernel part that is changed operating system to target board. The features of implemented system are (1) the para.llel processing of the events generated at each layer, as follows (2) the supporting necessary timers for the implementation of ISDW LAPD protocol from the kernel part by using software, (3) the recommanded SAP (Service Access Point) from CCITT was composed by using port function in the operating system. With the proposed method, the protocols of ISDH layerl, layer2 and layer3 (call control) were implemented by using the kernel part and related tests were carried out by connecting the ISDH terminal simulator to ISDN S-interface system using the ISDN LAPD protocol The results showed that ISDW S-interface terminals could be discriminated by TEI (Terminal Equipment Identifier) assignment in layer 2 (LAPD) and the message transmission of layer 3 was verified by establishing the multi-frame transmission and then through the path established by the LAPD protocol, a user data was tranfered and received on B-channel with LAPB protocol Thererfore, as new efficient ISDN S-interface environment was implemented in the thesis, it was verified that the implemented system can be utilized by connecting ISDW in the future to transfer a medical image data.

• The Transactions of the Korea Information Processing Society
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• v.4 no.10
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• pp.2512-2520
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• 1997

ITU-T Q.2931 and ATM Forum UNI 3.1 lead the standardization of signaling functions for the call/connection control at B-ISDN UNI. The one is applicable to the system in the public network, which provides the point-to-point call/connection control. The other is applicable to configure ATM private network mainly related with various terminal equipments. Domestic B-ISDN developers have developed ATM switches and B-NTs as network equipment, and B-TA as a terminal equipment. But many kinds of terminal-equipments are needed to provide various services in B-ISDN. If the public network can accommodate the terminal-equipments of UNI 3.1, it's very effective to accommodate manu kinds of terminal-equipments. Therefore, this paper identifies the problems that can be occurred on the signaling procedure, when B-ISDN the public network is connected to the UNI 3.1 terminal-equipment, and provides good alternatives that can handle this kind of call/connection well.

• Journal of Biomedical Engineering Research
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• v.17 no.1
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• pp.33-42
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• 1996

A multimedia remote ultrasound image transfer system for tole-medical services was implemented. The image data of the ultrasound scanner system of the slave is compressed using image compression system. It is transferred to the master PC via ISDN UNI(User-Network Interface) and decompressd by image decompression system. The total system is composed of three parts; first, the image capture card which transfers bidirection- al data between ultrasound scanner system and PC, second, image compression and decompression card, finally, ISDN TA(Terminal Adaptor) card for transferring the image. This system has a easy user interface because it is executed on the basis of MS-WINDOWS. So it is capable of serving medical services at a remote place.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1996.06a
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• pp.846-849
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• 1996

• Journal of Biomedical Engineering Research
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• v.14 no.4
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• pp.315-320
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• 1993

This paper deals with a subject for implementation of L+ayer 1 and Layer 2(LAPD) of ISDN user-network interface on the basis of CCITT recommandation I.411, I.412, I.441 (Q.921), I.450(Q.930) and I.451 (Q.931) for ultrasonic image transfer. For the implementa tion of LAPD protocol of ISDN in this study. PC-CARD based hardware(TA :Terminal Adopt) is proposed and operating system (PC-XINU) supporting the Multiprocessing is transplanted to it. As the Service Access Point(SAP) is accessed by using the port of XINU and Layers which consist of transmitting and receiving part are independantly processed for each other in this proposed system. It can be easy and flexible to implement LAPD protocol for the message transfer.