• Electronics and Telecommunications Trends
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• v.14 no.4 s.58
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• pp.1-9
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• 1999

In this paper, we summarize the lessons learned from the applications of the software reliability engineering to a large-scale software project. The considered software is the software system of the TDX-10 ISDN switching system. The considered software consists of many components, called functional blocks. These functional blocks serve as the unit of coding and test. The software is continuing to be developed by adding new functional blocks. We are mainly concerned with the analysis of the effects of these software components to software reliability and with the analysis of the reliability evolution. We analyze the static characteristics of the software related to software reliability using failure data collected during system test. We also discussed a pattern which represents a local and global growth of the software reliability as version evolves. To find the pattern of software of the TDX-10 ISDN system, we apply the S-shaped model to a collection of failure data sets of each evolutionary version and the Goel-Okumoto (G-O) model to a grouped overall failure data set. We expect this pattern analysis will be helpful to plan and manage necessary human/resources for a new similar software project which is developed under the same developing circumstances by estimating the total software failures with respect to its size and time.

• Electronics and Telecommunications Trends
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• v.10 no.1 s.35
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• pp.19-32
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• 1995

COMA 방식의 CMS가 이용하게 될 핸드오버 규격과 관련하여 기존 EIA/TIA IS-41규격의 발전 과정을 분석하였고, TSB-51 및 64를 바탕으로 변경될 IS -41 Rev. C 규격의 개정 방향을 고찰하였다. 아울러 이러한 분석결과를 TDX-10MX의 핸드오버 처리 절차에 반영하여 새로운 핸드오버 처리 절차에 대한 규격(안)을 제시하였다.

• ETRI Journal
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• v.10 no.1
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• pp.32-38
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• 1988

CCITT No.7 신호방식은 향후 도래할 종합 정보 통신망에 적합한 공통선 신호 방식이다. CCITT No.7 공통선 신호 기능의 일부인 신호 연결제어부는 메시지 전달부(MTP)의 상위에 위치하여 다양한 서비스 정보 및 망운용에 필요한 정보를 전달하는 역할을 수행한다. 본고는 CCITT Red Book 이후 계속되어온 CCITT 회의 자료를 근거로 하여 신호연결제어부의 전반적인 기능을 소개하고 향후 TDX-10에 실현할 신호연결제어부의 기능들에 대해 기술하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1994.10a
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• pp.62-66
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• 1994

본 연구에서는 실제 사용되고 있는 TDX-10 교환기의 subrack과 보드에 대한 진동 특성과 이 보드가 subrack에 실장되었을 때 진동 특성을 연구하였으며, subrack이 rack에 실장되는 조건을 갖는 진동 시험용 jig를 제작하여 보드와 subrack을 실장한 후 강제 진동시의 진동 전달 특성을 알아보았다. 본 연구의 결과는 내진동 특성이 우수한 전자통신 시스템 설계와 CDMA 이동통신 시스템의 HINA subrack 구조설계와 같은 개발장비 환경시험의 기초 자료로 활용될 수 있을 것이다.

• Journal of the Korean Operations Research and Management Science Society
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• v.25 no.3
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• pp.65-79
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• 2000

Based on the results of the internet service survey, the traffic demand forecasts of the AO/DI internet service and N-ISDN service have been performed for each channel(B-channel and D-channel). These traffic forecasts can be used as useful input data for investigating packet processing capacity of the TDX-10A switching system and suggesting guideline for capacity increasement.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.10
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• pp.26-32
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• 1997

The economical detection of dulal-tone multifrequency(DTMF) signals is an important factor when developing cost-effective telecommunication equipment. Each channel have independently a DTMF receiver, and it informs the detected signal to processors of the TDX. This paper proposes the linear prediction algorithm for the spectrum analysis. As a experimental resutls, it can obtain the improved performance to the DTMF receivers and reduce the real-time processing and memory waste.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1990.04a
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• pp.289-298
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• 1990

A conceptual model of tentative packet handler subsystem (PHS) of TDX-10 is presented. This model is used to analyze the capacity of PHS especially when packet bus (PBUS) is bottleneck. In the viewpoint of performance analysis, cyclic server system and token bus LAN are utilized in modeling PHS.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.11
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• pp.2179-2188
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• 1994

In this paper, we studied the deployment of AIN(Advanced Intelligent Network) that was recommended by ITU-T there are five methods of deployment. Here we divided these methods into two types. One is the direct connection with SCP(Service Control Point) and IP(Intelligent Peripheral) via No.7 and the other is the indirect connection with SCP and IP Through SSP(Service Switching Point). First, we suggested the structure of AIN SSP and defined S/W functional blocks. Second, we proposed H/W functional extension for interaction with IP. On the basis of the suggested structure, we mathematically evaluated and simulated two types of the deployment of AIN. In the result, we knew that, in comparison with the indirect method, the direct method was effective.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.3
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• pp.451-461
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• 1994

For developing countries which are in infant state of data communication services or don`t have their own Packet Switched Public Data Network(PSPDN), we present the strategy to construct the public data communication network, which guarantees the easy diffusion of data communication services, agrees with trends of telecommunication technology, and maximizes the outcomes to investments. With analyzing the characteristics of telecommunication infrastructures and demands of data communication services in a developing country, we show that the introduction of ISDN is the best solution for constructing a public data network. We also suggest aggressive approach to realize the packet switching functions into ISDN switching system and the networking scenario consisting of three graceful steps, based on the evolution of network architectures. Finally we show that the TDX-10 ISDN switching system, which is designed especially for developing countries, is helpful to commence the data communication era.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.12
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• pp.2340-2352
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• 1994

Under the current IN(Intelligent Network) Architecture, most of their function were performed in SSP(Service Switching point), so the provision or modification of service was limited. To over come these limitation, the structure of 'AIN(Advanced Intelligent Network)' emerged. In this paper, SSP for AIN structure is designed and its performance is evaluated. In other words, the requirements for AIN service implementation are specified on the basis of ITU-T Recommendations. From these requirments and TDX-10 Exchange architecture, the SSP for AIN structure is designed, and its performance is analyzed through the method of simulation and analytical modeling. As a conclusion of this paper, when the system is operated as a standard model, the maximum throughput is 1,270,000 BHCA for Free Phone Service and 1,190,000 BHCA for Credit Call Service. The processors in INS(Interconnection Network Subsystem) are proved to be bottleneck elements. To enhance the performance, several suggestions such as processor and link speedup, and other D_bus service policy are proposed.