• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.7
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• pp.1018-1027
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• 1993

In this thesis, we evaluate the performance of the TDX-IB/ISDN Switching System ISS (ISDN Subscriber Subsystem) which is the ISDN user-network interface module. For this evaluation, performance indices are established and major performance parameters which influence message processing are extracted by studying the ISS structure and mechanism. To reflect these parameters, simulation model is developed and simulated. From the result of maximum throughput, message delay time, etc. , ISS message processing capability is evaluated and several method to enhance the system performance is proposed, by analyzing the system bottleneck element.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10B
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• pp.1861-1866
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• 1999

ISDN provides mB+1D channel to users. An AO/D1 scheme means D-channel can be used for a permanent low speed connection. When user needs more bandwidth for high speed transfer, the AO/D1 scheme automatically provide greater capacity in the shape of ISDN B-channels. In this paper, we analyze the performance of the AO/D1 scheme with multiple ON-OFF sources in ISDN. We consider multiple ON-OFF sources connected through mB+1D ISDN link. Without the AO/D1 scheme, the required bandwidth will be the sum of peak bandwidth of all sources. With the implementation of the AO/D1 scheme, the required bandwidth is reduced to what is really needed.

• Information and Communications Magazine
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• v.11 no.4
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• pp.62-70
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• 1994

This paper discusses the LAN interface technics physically applicable to the ISDN exchange system through frame relay without changing of the basic exchange architecture. To ensure the success of frame relaying, it's interworking with the existing X.25 services is very imported, and for this purpose both X.75 and 1.122-based interworking alternative must be considered. Definition required to frame relay, interconnection of remote bridge and ways to design the Frame Handler carrying a frame realying in the ISDN node was introduced here. Subsequently, alternatives using the X.25 and X.75 or 1.122 as well as interconnection mechanism LAN and ISDN for the LAN interface and LAN and/or LAN interface and ISDN through frame relay was individually introduced. Through frame relay applications in the major countries, the achievement of high speed frame relaying service to the LAN was introduced.

• 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 Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.2
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• pp.115-127
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• 1991

In this paper. we dIscussed wIth the ISDN numberIng system of Korea 2digIt of NDC(National Destination Code)is assigned to the common carrier indenttification and an other the service network identification code as conbining the flIst and second dIgIt. The last ot NDC is applicable to for each area code. Resulty. we become 10 digit number for toll system vice 7 digit for local numbering. It is satisfactory to CCITT recommandtion and also. We has been suggested that existing network the mobile. pagget, FAX, TELEX and public networks are able to be connetcted to the ISDN. Near the 1994. we guess that it is fully occupied with 7 digit number to the metropolitan area to solve this problem, after divide to 3 part provincial area southern. nothem and mid-Korea. We suggested that special number system are reorganized with the new and existing service numbers plan. Although, we don't deal with the SA of ISDN numbering systems. Resultly, know that we are to design efficiently number system as 3 digit code for ISDN/NSN.

• ETRI Journal
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• v.10 no.1
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• pp.3-13
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• 1988

With the contunuing trends towards an information based society, telecommunications services are becoming an integral part of social activities. So, emphasis on ISDN is growing rapidly and placed on supporting integrated services delivery of different levels to the end user. The end user’s perception of an integraged services delivery(in particular, ISDN services) should reflect three interrelated capabilities, ISDN access capabilities and ISDN network capabilities. For turning the ISDN concept of above capabilities into reality, we have implemented the experimental system on user-network interfaces, which are three kinds of implementations in user access arrangements, namely basic access, intermediate rate multiplexed access and primary rate multiplexed access. Through these implementations, NTE(Network Terminating Equipment) is used for single basic access [2B+D], IMUX (Intermediate rate Multiplexer) for 4 basic accesses [4X(2B+D)] and PMUX(Primary rate Multiplexer) for [10/12 X (2B+D)]. This paper describes the outlines of system features on user access equipments, system architectures of testbed and experiment result of each access arrangements.

• Electronics and Telecommunications Trends
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• v.14 no.4 s.58
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• pp.23-41
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• 1999

활성화된 PSTN/N-ISDN 망과 B-ISDN망에서 공중망의 번호체계로 사용하는 ITU-T E.164에 대하여 각 망에서의 번호체계 및 번호사용방법(Dialing Plan)을 비교, 검토하고, B–ISDN 망의 E.164 번호계획(Addressing/Numbering Plan)/번호사용방법이 PSTN/N-ISDN 망과는 다른 방법으로 적용하여야 하는 이유 및 방법과, 호처리시 착신번호와 함께 루팅에 사용되는 중계망 선택기능을 위한 망 식별번호(Network Identification)가 망의 번호체계와의 연관성을 살펴보기 위하여 본 고에서는 PSTN/N-ISDN 망과 B-ISDN 망의 E.164 번호계획과 번호사용방법, 중계망 선택기능에 대하여 기술하고, 기존 통신망과의 서비스 연동을 위한 E.164 번호체계에서 B-ISDN 망의 식별번호 사용에 대하여 기술하고자 한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.14 no.6
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• pp.621-632
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• 1989

According to the conventional network evolving towards ISDN, various connection types may be existed in the networks and subscriber-network interfaces. For this reason it is necessary to study the signalling conversion algorithms and the implementation models. In this paper, after surveying the signalling conversion method between the ISDN subscriber and the conventional network, the signaling conversion algorithms are proposed. Based on this algorithms the matching system is designed and developed. Also the validity of this system and the utility of designed software and hardware functions are verified through experiments.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.730-732
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• 1999

인터넷이 급성장함에 따라 사용자들은 좀더 편리하고 저렴한 인터넷 서비스를 원하고 있다. 이에 기존 전화망 보다 2배이상 높은 대역폭을 제공하면서 전화와 인터넷을 동시에 사용 가능한 ISDN(Integrated Services Digital Netowork)에 대한 관심이 급증하고 있다. 하지만, 빈번하게 발생하는 원인불명의 ISDN 서비스 중단이 ISDN망 활성화에 큰 장애요인이 되고 있는 실정이다. 이것은 ISDN 가입자장치 관리에 대한 표준 및 관리 구조가 제대로정립되지 않기 때문이다. 본 논문에서는 SNMP(Simple Network Management Protocol) 망 관리 기법을 ISDN 가입자장치 관리에 적용하고, ISDN 가입자장치 관리에서 다루어야 하는 문제점과 이에 대한 해결방안 및 향후 연구사항에 대해 다룬다.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.719-722
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• 2000

It is essential to develop the internetworking strategies between the OBP satellite B-ISDN and the terrestrial B-ISDN for the economical and efficient implementation of the future network infrastructure. We have considered the implementation issues of the emerging B-ISDN, especially interworking strategies of the terrestrial B-ISDN with the OBP satellite B-ISBN. We proposed interworking model between terrestrial B-ISDN and OBP satellite B-ISDN NNI signaling protocol, and describes the design and verification of the interworking protocol. For the verification, interworking protocol is modeled by Predicate/Action Net derived from Petri Net and the designed model is analyzed by reachability tree. Using Unix socket, the verified interworking protocol is implemented in two workstations and implemented interworking protocol is tested by local test method which is outstanding in error detection and recommended by ISO.