• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.723-726
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• 2000

In this paper, we present an abstract object-oriented plat-form model .suitable for the real-time distributed telecommunication system. The proposed platform is constructed upon the extended version of the real-time, distributed operating system, SROS(Scalable Real-time Operating System), that is developed at ETRI and successfully operated in the ATM switching system for several years. The object-oriented software development and maintenance methodology will resolve the current software crisis in the area of telecommunication and switching systems due to the everlasting maintenance about the huge amount of the existing software and the ever increasing needs for the better and new communication services. In general, an object-oriented software platform realizes the object-oriented methodology and possesses many good aspects like high productivity, better reusability, easy maintenance, et at. The platform is also designed to present the distributed multimedia service in addition to real-time event delivery. Recently, we have been implementing a couple of prototype bated on the proposed platform. Reflecting the evaluation results from these prototypes, the final platform specification will be determined.

• Information and Communications Magazine
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• v.16 no.2
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• pp.107-118
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• 1999

인터넷 사용자가 급진적으로 증가함에 따라 오늘날의 인터넷 트래픽의 양 또한 폭발적으로 증가하였으며 기존의 라우팅 기법을 이용하는 라우터를 사용하는 경우에는 라우팅 시의 지연으로 인해 고속 서비스를 요구하는 사용자의 욕구를 충족시키기는 어려울 것이다. 이와 같은 문제는 앞으로의 인터넷 사용자의 수요 및 요구 서비스를 예측할 때 조속히 해결해야 할 중요한 문제라고 할 수 있다. 고속 인터넷 서비스를 제공할 수 있을 것으로, 예상되었던 IPOA, MPOA, IP Switching, Tag Switching, MPLS 등의 기술 중에서 MPLS는 ATM 교환기를 이용하여 사용자의 요구에 부응할 수 있는 양질의 서비스를 제공할 수 있을 것으로 기대하고 있다. IETF에서는 MPLS 표준화가 활발히 진행중이다. 본 고에서는 ATM 교환기를 기반으로 MPLS 기술을 이용하여 ATM 기반의 인터넷 서비스를 제공할 수 있는 방법에 대해 기술한다. 본 시스템은 ATM 교환기와 연결된 MLSP 상에서 LDP, BGP 등의 프로토콜을 구현함으로써 LER 및 LSR로서 동작할 수 있도록 하여 대용량의 인터넷 트래픽을 고속 처리할 수 있는 기능성을 제시한다.

• International Journal of Contents
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• v.1 no.1
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• pp.45-49
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• 2005

If the service provider provides mobile service with mobile switching centers that use different handoff message format, the soft-handoff between mobile switching centers is not available and the hard-handoff scheme is used instead. When this occurs, calls are often disconnected or there is an interruption of service. This can be very annoying to a mobile user. We propose the handoff subsystem of the ATM switch which provides the soft-handoff between wireless cells under the control of different MSCs. The proposed handoff subsystem transforms the handoff message format of the source MSC to that of the destination MSC. It also provides efficient routing scheme that distributes handoff packets to balance the traffic load.

• The Transactions of the Korea Information Processing Society
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• v.6 no.1
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• pp.175-181
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• 1999

There are issues regarding how some of traffic parameters should be set so that ATM and non-ATM service parameters can be compatible. For example, policing method used by frame relay based on CIR(committed information rate) will not exactly match the ATM UPC(Usage Parameter Control) method. ATM and the frame relay have different transfer modes and traffic parameters. The cells and frames are police by their own traffic control schemes. For the same information, the real traffic of the ATM side takes greater bandwidth than that of the frame relay side caused by ATM cell format and AAL5 format. IN both networks this bandwidth than that of the frame relay side caused by ATM cell format and AAL5 format. In both networks this bandwidth ratio should be considered on traffic parameter mapping to maintain their QoS and to perform efficient network resource management. In this paper we describe traffic parameter mapping schemes between frame relay and ATM in ATM network and how to expect the bandwidth ratio to maintain FR QoS in ATM network. We assumed frame length distribution to Erlang or Exponential probability density function.

• Proceedings of the IEEK Conference
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• 2000.06a
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• pp.119-122
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• 2000

차세대 네트워크인 MPLS 망에서 기존의 하드웨어 기반의 스위칭 방식인 ATM 스위치를 이용하여 MPLS 라우터, 즉 ATM LSR(Label Switching Router)를 구현 할 경우 ATM 스위치 상에서 MPLS 서비스와 ATM 서비스를 동시에 지원하기 위해서는 두 자원을 공유해야 하는 문제점이 발생한다. 본 연구에서는 두 가지의 자원을 동적으로 할당하기 위하여 ATM 스위치를 제어하는 GSMP를 이용하여 망 초기에는 Static 방식으로 라우팅을 되게 하고, 특정 링크상에 폭주가 발생할 때 Dynamic 요청신호를 GSMP에 전달해 링크 이용률이 가장 적은 포트를 이용함으로서 서비스의 효율을 향상 시켰다.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.303-306
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• 2000

In this paper, we propose VC merge capable hardware architecture for scalability based on ATM switching fabric. We implemented a scheduler for configuring crossbars in input-queued switches which support virtual output queues at the input ports. Also, we implemented VC merge capable scheduler at the output ports. We verified the proposed model by using C language, and designed with VHDL language. Then, we simulated and synthesized it with software of the SYNOPSYS corporation.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.295-298
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• 2000

본 논문은 ATM교환기에서 Non-ATM정합을 위한 미디어게이트웨이의 개발방안과 하드웨어, 소프트웨어 구조에 대해서 기술한다. 미디어게이트웨어의 하드웨어 구조는 ATM계층처리보드와 다중화처리보드 및 서비스보드들로 구분되며 Non-ATM을 서비스별로 처리할 수 있는 보드를 모듈당 최대 8매까지 실장 할 수 있다. 다중화처리보드는 ATM셀 MUX/DEMUX기능과 IPC송수신기능을 처리하고 서비스보드의 링크상태관리, 운용기능을 수행한다. 서비스보드의 종류는 프레임릴레이, 회선대행, AAL2 트렁킹, N-ISDN중계선 연동기능을 각각 수행한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.3C
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• pp.201-210
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• 2002

A number or MPLS ATM switching system have been proposed to increase the access speed or current routers, but they cannot satisfy the Internet users who use diverse applications. So they are required to support the so-called differential service, which discriminates service behaviors according to the service class. In this paper, to support this differential service we suggest an LSP control method, which uses the extended LDP message and establishes several different LSPs for each FEC according to the service class. Also, we propose an marking algorithm using the cell loss priority field or ATM cells in order to process the differential service according to application categories. In addition, we present a forwarding procedure based on the LSP control method and the marking algorithm. A forwarding model applied this forwarding procedure can be easily implemented with a minimum modification of existing MPLS ATM switching systems. Therefore, we can save cost and time needed to implement the proposed model. Finally, we estimate the performance behaviors of the proposed application-based forwarding model by the AweSim simulation package.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.265-268
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• 1998

This paper evaluates the VSN(Virtual switch Network) characteristics in the internal call processing of IMT-2000 switching system, which is composed of VSN instead of ATM switch network. In results, internal call establishment delay is increased approximately 5.4msec than the conventional ATM switching system. The evaluated condition is the load 0.8, and the 100km distance between VSNs. It is confirmed that the VSN has the potentiality in the practical implementation.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.2
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• pp.31-39
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• 1998

In this paper, we have presented a quantitative performance effect of CCP(Call Control Processor) when SAAL(Signalling ATM Adaptation Layer) function is distributed from CCP to SIMs(Subscriber Interface Modules) in an ATM switching system with distributed architecutre. For the performance analysis, SLAM II simulation language is used and subscriber signalling messageand inter-processor communication messages according to Q.2931 based local call processing procedure are taken into consideration in the proposed queuing network model. The results of simulation are compared with in case of processing SAAL function on CCP. It is observed that the processing utilization of CCP reach 24,000 BHCA and 25,700 BHCAwhen SAAL function load amounts to 10% and 20% of the processing time of the total message, respectively. These values shows that the processing utilization of CCP is alleviated about 7% in comparison with 2,000 BHCA in case that SAAL function is carried out on CCP. Consquently, it is shown that we have to consider seriously how to distribute the functions concerning call processing in a large cale ATM switching system architecture accomodating a number of SIMs.