• The Optical Journal
• /
• v.12 no.2 s.66
• /
• pp.2-5
• /
• 2000

올해 세계 PC & WEB 카메라 생산량은 전년에 비해 3배에 달하는 급성장을 이뤄 1,050만 대가 될 것으로 예상하고 있으며, 이중 가장 많은 비중을 차지할 곳은 대만이다. 올 하반기부터 일본을 시작으로 생산될 IMT-2000은 내년에 1,200만대가 생산될 것으로 보인다. 국내에서는 내년 상반기부터 생산에 들어가 2002년부터 서비스를 할 예정이다.

• 한국정보통신설비학회:학술대회논문집
• /
• 2008.08a
• /
• pp.166-170
• /
• 2008

In 2006, ITU-R estimated the spectrum requirements for IMT-Advanced including IMT-2000 and its enhancements. And WRC-07 indentified four new spectrum bands for IMT system. Based on these results, there are many activities which are related with IMT system and its spectrum inside and outside of the country. This paper covers the next generation mobile telecommunication spectrum issues and outlook for the future of it.

• Proceedings of the Korean Information Science Society Conference
• /
• 2000.10c
• /
• pp.198-200
• /
• 2000

IMP-2000은 다양한 이동전화 시스템의 규격을 통일하여 세계 어느 곳에서도 하나의 단말기 또는 사용자 접속 카드로 서비스를 이용할 수 있도록 하는 글로벌 멀티미디어 서비스이다. 본 논문은 IMP-2000의 어플리케이션중 범용 개인 통신 서비스인 UPT 서비스의 정보 보안 방법을 모색하여 본다. 과금 서비스인 UPT 서비스는 malicious person의 공격에 의한 금전적 손실을 차단하기 위하여 가입자 인증 정보의 보안이 필요하다. 본 논문에서는 ATM 교환기를 사용하는 IMP-2000 시스템에서 지능망 프로토콜로 메시지를 주고받는 UPT 서비스 시나리오 및 공격 시나리오를 분석하고, RSA 암호 기법을 적용한다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.15 no.3
• /
• pp.242-250
• /
• 2004

In this thesis, a new broadband PIFA(Planar Inverted-F Antenna) for PCS and IMP-2000 applications is designed. The dual-L antenna structure is adopted in order to improve the characteristics of PIFA which usually has a narrow band. The height of the antenna is fixed 6 mm considering terminal's thickness and the structure is deformed into the folded radiation patches to minimize the size of the antenna. The bandwidth of a realized antenna is 1.66∼2.35 ㎓(34.5 %) fur return loss below -10 ㏈ which contain the required bandwidth of PCS and IMT-2000. And Monopole antenna with λ/4 length is designed and compared with dual-L with folded patch in SAR. 1 g and 10 g averaged peak SAR of PIFA are about 25.7 %, 30.3 % lower than those of monopole antenna respectively.

• Journal of the Institute of Electronics Engineers of Korea TE
• /
• v.37 no.2
• /
• pp.75-82
• /
• 2000

In this paper, described is the comparison of performances based on the computer simulation under IMT-2000 environment between multicode and multicarrier CDMA system for the design of wireless systems using wideband CDMA technology. From simulation results, it can be concluded that both multicode and multicarrier CDMA scheme show comparable performances. Diversity scheme of RAKE receiver is indispensible for both multicode and multicarrier CDMA systems under IMT-2000 outdoor B and vehicular B channel environment. Either Hadamard matrix or PN sequence can be used as the orthogonal code as far as the orthogonality is kept. Finally, with increasing chip rate and less users, performance is getting better.

• Proceedings of the KSME Conference
• /
• 2000.11a
• /
• pp.778-782
• /
• 2000

Deep drawing and ironing are the major process used today in manufacturing of battery case used in cellular phone and IMT-2000 from aluminum. The same technology is utilized in manufacturing of steel or aluminum rectangular cans for components of medical instrument, portable PC, walkman and so on. Most of these processes require multi-stage ironing following the deep drawing and redrawing processes. The practical aspects of this technology are well known and gained through extensive experiment and production know-how. However, the fundamental aspects of theses processes are relatively less known. Thus, it is expected that process simulations using FEM techniques would provide additional detailed information that could be utilized to improve the process condition. This paper illustrates the application of process modeling to deep drawing and redrawing operations with the cellular phone and IMT-2000. A commercially avaliable finite element code LS-DYNA3D was used to simulate deep drawing and redrawing operations.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.11 no.6
• /
• pp.996-1005
• /
• 2000

This paper proposed a novel broadband ceramic dielectric antenna by improving the conventional broadband technique that very high permittivity material is attaching to one side of low permittivity material. The broadband ceramic dielectric antenna can be designed by using our proposed method, and it overcomes the disadvantage of narrow bandwidth problem. For the proposed ceramic dielectric antenna, a 10 dB return-loss bandwidth of 33.9% has been achieved. The measurement and numerical results(Finite Element Method) are performed and confirmed to a good agreement with each other. The proposed ceramic dielectric antenna is designed and implemented to extend enough the coverage of dual band (PCS+IMT-2000).

• Journal of the Microelectronics and Packaging Society
• /
• v.7 no.3
• /
• pp.19-25
• /
• 2000

In this paper, we describe RF receiver module for IMT-2000 handset with 5 MHz channel bandwidth. The fabricated RF receiver module consists of Low Noise Amplifier, RF SAW filter, Down-converter, If SAW filter, AGC and PLL Synthesizer. The NF and IIP3 of LNA is 0.8 dB, 3 dBm at 2.14 GHz, conversion gain of down-converter is 10 dB, dynamic range of AGC is 80 dB, and phase noise of PLL is -100 dBc at 100 kHz. The receiver sensitivity is -110 dBm, adjacent channel selectivity is 48 dBm.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.37 no.7
• /
• pp.24-30
• /
• 2000

In this paper, we proposed an fiber-optic transceivers based on the analog optical transmission techniques of incorporating the SCM (subcarrier multiplexing) and WDM (wavelength-division multiplexing ) method, which can be used to transmission of IMT-2000 and PCS wireless frequency band and analyzed overall those parameters related with fabrication. Especially in the impedance matching network between RF signal and LD, we proposed the method of deriving optimal performance using simulation techniques. In the frequency band of 1.7GHz∼2.25GHz, experimental data for the gain flatness and the noise floor of the optical link were also presented $\pm$1.5dB and -130dBm respectively when the link Rain was 0dB.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.10A
• /
• pp.1512-1520
• /
• 2000

The wireless communication network is evolving toward IMT-2000 for providing various multimedia services. In order to accomplish this ultimate goal the effective schemes are required which can dynamically utilize the limited wireless resources based on different traffic characteristics of various services. This paper proposes a novel bandwidth allocation and call admission control scheme to transmit multimedia traffic based on the bandwidth reservation procedure using direction estimation in the IMT-2000 This scheme estimates the position of mobiles based on the mliticriteria decision making in which uncertain parameters such as RSS(Received Signal Strength), the distance between mobile and base station the moving direction and the previous location are participated in the decision process using aggregation function in fuzzy set theory. Its effectiveness is investigated by simulation.