• Journal of Korean Institute of Industrial Engineers
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• v.32 no.3
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• pp.180-190
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• 2006

We evaluate the economic value and the optimal investment timing of IMT-2000 in Korea, in the perspective of a service provider who owns the business license for IMT-2000, by using the real options analysis. The result clearly shows the project value with options is positive and delaying the investment is more favorable to the provider. Binomial lattice approach, in which we try to describe American call option and sequential compound option, and sensitivity analysis present the optimal decisions according to future states and enable the management to make decision strategically and proactively.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.397-400
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• 2001

In this paper, to improve bandwidth of microstrip antenna, we discussed the patch structure using Aperture Stacked Patch. To provid PCS service and IMT-2000 service simultaneous, a microstrip patch antenna needs impedance bandwidth of 22%. But typical microstrip patch antennas have impedance bandwidth of 3∼6%. To analyze characteristics of microstrip pach antenna, we used Ensemble of commercial software. The microsrtip patch antenna was designed and fabricated, tuned. We get following results; 650MHz(33%) of impedance bandwidth for VSWR 1.5. The measured gain of ASP microstrip antenna is 6.94dBi.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.4
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• pp.366-372
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• 2002

A wideband stacked patch antenna fed by an L-strip feeder is studied experimentally. The objective of this paper is to design small wideband antenna for PCS and IMT-2000 service. Experimental results confirm that an impedance bandwidth(VSWR$\leq$2) of 704.7 MHz(35.95 %) is achieved at PCS and IMT-2000 frequency band. The studied antenna can be designed easily for extension of away because it has simple structure.

• Journal of the Microelectronics and Packaging Society
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• v.11 no.1
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• pp.7-11
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• 2004

In this paper, the wideband microstrip patch antennas for the Personal communications Service (PCS : 1750∼1870 MHz) and International Mobile Telecommunications-2000 (IMT-2000 : 1920∼2170 MHz) dual band are studied. Experimental and simulation results on the dual band antenna are presented. Simulation results are in good agreement with measurements. The experimental and simulation results confirm the wideband characteristics of the antenna. The studied antenna satisfied the wideband characteristics that are required characteristics for above 420 MHz impedance bandwidth for the PCS and IMT-2000 dual band antenna. In this paper, through the designing of a dual band antenna, we have presented the availability for PCS ＆ IMT-2000 base station antenna. An impedance bandwidth of 33% (VSWR<1.5, 650 GHz) and a maximum gain of 7dB can be achieved. The radiation pattern is stable across the passband.

• The KIPS Transactions:PartC
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• v.9C no.1
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• pp.17-20
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• 2002

IMT-2000 technologies are divided 3G packet data system that using mobile IP and GPRS that based on the GSM networks. These technologies Push introduce mobile IP to support seamless roaming. In mobile If environments, use AAA server such as RADIUS or DIAMETER to provide authentication service for dial-up computers. This factor is important for mobile nodes. Mobile If require strong authentication between mobile nodes and home agents. We propose application of AAA protocols for smooth handoff mechanism in IMT-2000 environments.

• TTA Journal
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• s.78
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• pp.77-83
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• 2001

• The Transactions of the Korea Information Processing Society
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• v.7 no.5
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• pp.1536-1543
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• 2000

In this paper, we propose a multiple access scheme for efficient transmission of realtime and non-realtime data in IMT-2000 through cdma2000's CDMA MACD. On the contrast to the conventional circuit-based service, this framework is packet-oriented service. maximum number of simultaneous subscribers increases due to the statistical multiplexing based on variable transmission rate of realtime data. System performance is evaluated and compared with conventional circuit-based scheme considering transmission delay and channel utilization by computer simulation.

• Journal of KIISE:Information Networking
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• v.27 no.2
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• pp.219-225
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• 2000

In order to provide a proper mobile internet service, Mobile IP is necessary to support IP mobility. Service network should be a backbone network among mobile agents which support mobility, and MPLS(Multi-protocol Label Switching) of IETF(Internet Engineering Task Force) is being considered as a backbone network because of its speed, scalability and the excellent service capability. MPLS, however, doesn't provide a way to support the mobility of the nodes. In this paper, we present an efficient IMT-2000 network architecture using MPLS to handle Mobile IP. The proposed architecture combines the MPLS label distribution and Mobile IP registration. It doesn't use the layer 3 encapsulation, instead it uses layer 2 for tunneling the data, reduces the size of the header, and it can tunnel the data without delay, which is needed to look up the mobility binding list, as a result.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.577-580
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• 2003

최근 차세대통합네트워크(NGN), ALL-IP 망 진화 방향과 함께 동기식과 비동기식 IMT-2000 망의 통합(Convergence) 또는 연동(Harmonization)에 관한 연구가 활발히 이뤄지고 있으며, 이동통신 망의 개방화에 대한 분위기가 점차 무르익어 가고 있다. 이러한 추세에 UMTS, cdma2000, WLAN 과 같은 서로 다른 방식의 무선 액세스 망으로부터 요구되는 무선인터넷 접속 요구를 하나의 통로로 연결하고 수용할 수 있는 모바일 액세스 통합 게이트웨이가 필요하다. 본 논문에서는 차세대 네트워크 발전 방향과 이동통신 망 개방의 흐름에 맞추어 동기식 망과 비동기식 IMT-2000 망에서 동시에 무선인터넷 서비스 접속을 제공하는 통합 게이트웨이 시스템(A-MiDAS)을 개발하기 위한 형상 설계 방법과 시스템 개발 시 고려사항 등에 대해서 기술한다.

• International Journal of Contents
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• v.1 no.2
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• pp.13-17
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• 2005

Base Station Controller which belongs to IMT-2000(International Mobile Telecommunication - 2000) network has several types of structure for efficient control protocol. This difference of structure occurs two different protocols for call handling. Recently the need of IMT-2000 is highly increasing, so it is important to analyze the performance of processors and IPC(Inter-Processor Communication) module with structure of BSC and protocol difference. This paper presents the performance comparison of different types of BSC in view of processor utilization, waiting time, queue length and QoS(Quality of Service) through the simulation model.