• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.13-16
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• 1999

The terrestrial/satellite hybrid network may replace or supply the terrestrial network in some areas or certain application. Futhermore, it can play an important role in the development of B-ISDN due to their features of flexible wide coverage, independent of ground distances and geographical constraints, multiple access and multipoint broadcast. Also, satellite have the capability to supply terrestrial ATM and B-ISDN with flexible links for access networks as well as trunk networks. This paper describes the design and verification of the interworking protocol between terrestrial B-ISDN and satellite network. For the verification, the designed interworking protocol is modeled by Petri-net and analyzed by reachability tree.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3098-3103
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• 2009

In this paper, self-similar characteristics over statistical approaches and real-time Ethernet network traffic measurements are estimated. It is also shown that the self-similar traffic reflects real Ethernet traffic chareacteristics by comparing TCP-MT source model which is exactly self-similar model to the traditional Poisson model.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1998.04a
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• pp.304-308
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• 1998

Technical advances in computer networks and the Internet bring a new communication era and provide effective solutions for cooperative works and research. These technological advances introduced the concept of cyberspace that many people involve reseach and a project at different locations at the same time. In this paper, we present a fast and effective interaction protocol that is aeapted to the COLAB(COIIaborative LABoratory) Systems which use a high-speed ATM Network. The CCOLAB systems is developed for researchers those who are doing a large project on the collaborative research environment. The interaction protocol that we developed supports multi-session and multi-channel on the TCP/IP Network and provides more flexible solution to control multimedia data on the network.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.350-354
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• 2008

IP-based mobile communication system is one of the key research items in the mobile networks for a long time. But, due to some technical issues and no need of markets, it is still not full-fledged. Recently, CDMA and WCDMA service providers want to introduce IP-based network connectivity. Even though their efforts, the main network intra-structure depends on ATM or HDLC technology. This article describes a good example of commercialization of IP-based mobile communication systems. Our research is not experimental system but a in-service system - replacing the existing equipments with new IP-based systems. In this paper, we introduce IP related technologies used in our research such as IP-based ATCA(Advanced Telecommunications Computing Architecture) platform, HA(High Availability) redundancy, IP multicast, network redundancy techniques, multi-link bundling and IP header compression. These are already well-known to internet domain. We mix them with mobile communication systems concretely.

• The Transactions of the Korea Information Processing Society
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• v.6 no.7
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• pp.1909-1918
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• 1999

The terrestrial/satellite hybrid network may replace or supply the terrestrial network in some areas or certain applications. For example, it may play a major role in global B-ISDN or in certain areas where the deployment of optical cable is not feasible, especially at the early stage of implementing terrestrial B-ISDN. Furthermore, it can play an important role in the development of B-ISDN due to their features of flexible wide coverage, independent of ground distances and geographical constraints, multiple access and multipoint broadcast. Also, satellite have the capability to supply terrestrial B-ISDN/ATM with flexible links for access networks as well as trunk networks. This paper describes the design and verification of the interworking protocol between terrestrial B-ISDN뭉 satellite network. For the verification, the designed interworking protocol is modeled by Petri-net and the model is analyzed by reachability tree.

• Journal of Internet Computing and Services
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• v.1 no.2
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• pp.29-37
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• 2000

Asynchronous transfer mode is flexible to support multimedia communication services using asynchronous time-sharing and statistical multimedia techniques to the existing data communication area, ATM ABR service controls network traffic using feedback information on the network congestion situation in order to guarantee the demanded service qualities and the available cell rates, In this paper we apply the control method using queue length prediction to the formation of feedback information for more efficient ABR traffic control. If backward node receive the longer delayed feedback information on the impending congestion, the switch can be already congested from the uncontrolled arriving traffic and the fluctuation of queue length can be inefficiently high in the continuing time intervals, The feedback control method proposed in this paper predicts the queue length in the switch using the slope of queue length prediction function and queue length changes in time-series, The predicted congestion information is backward to the node, NLMS and neural network are used as the predictive control functions, and they are compared from performance on the queue length prediction. Simulation results show the efficiency of the proposed method compared to the feedback control method without the prediction, Therefore, we conclude that the efficient congestion and stability of the queue length controls are possible using the prediction scheme that can resolve the problems caused from the longer delays of the feedback information.

• Journal of the Korea Society for Simulation
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• v.3 no.1
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• pp.151-165
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• 1994

Broadband network based on the Asynchronous Transfer Mode(ATM) concept are becoming the target technology for the emerging Broadband Integrated Services Digital Network(B-ISDN). Since B-ISDN is very complex and requites a great amount of investment, optimum design and performance analysis of such systems are very important. Simulation can be widely used to analyze and examine the broadband network behavior. However, for the complicated system like broadband networks it is extremely difficult and time-consuming to develop a complete model for simulation. In this paper, an object-oriented modeling approach for the broadband network simulation is presented for the effective and efficient modeling. Object-oriented approaches can provide a good structuring capability for complicated simulation models and facilitate the development of reusable and extensible simulation models. We have developed an object-oriented model which consists of object model and behavior model. In the object mode., the components of the broadband network and both constant bit rate(CBR) and variable bit rate(VBR) traffic types of call level, burst level, and cell level are modeled as object classes. In the behavior model, the dynamic features for each object class are represented using the state transition diagram. It has been shown by illustration that objectoriented modeling is an effective tool for modeling the complicated B-ISDN.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.225-228
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• 2000

In this paper, we present the design of AAL2/AAL5 Type conversion Unit using among BSC, BTS, Core-Network in IMT-2000 system. We first briefly introduce the B-ISDN ATM Adaptation layer specification of Type 2 AAL and Type 5 AAL, and describe conversion flow and each module. And then this paper has designed AAL2/AAL5 Type Conversion Unit and simulated it.

• Information and Communications Magazine
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• v.21 no.7
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• pp.94-116
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• 2004

1968년 ARPA 네트워크의 출현 이후 음성 서비스 위주의 네트워크와 데이터 서비스 위주의 네트워크는 서로의 서비스를 수용하기 위해 노력해왔다. 음성 기반의 네트워크에서 데이터를 수용하기 위한 노력은 ‘꿈의 망’으로 그친 ISDN(Integrated Services Digital Network)으로 나타났고, 데이터 기반의 네트워크에서 음성을 수용하기 위한 노력은 보편적인 비연결형 데이터 서비스와는 대비되는 B-ISDN(Broadband-ISDN)으로 나타났다. 이후 다시 B-ISDN은 IP 서비스의 수용을 위해 ATM 교환기를 MPLS(Multi Protocol Label Switching) 교환기로 대치하여 보완하고 있지만, VoIP(Voice over IP)등 음성서비스의 제공에는 아직 완전한 해법이 제시되지 못하고 있다.(중략)

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.109-112
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• 1999

In this paper, we propose more effective method of label allocation on Multi-Protocol Label Switching (MPLS) which is IP over ATM integrated model. We research the problems, one is using downstream label allocation method case, the other is using both downstream and upstream label allocation method. Easily we can solve this problem through the downstream-on-demand label allocation method with RSVP(Resource ReSerVation Protocol). In experiment we can find 1.5~28% error which will be fixed by using downstream-on-demand label allocation method.