• The Journal of the Korea institute of electronic communication sciences
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• v.1 no.1
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• pp.70-80
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• 2006

The large portion of communication service areas move from a legacy wire-line voice service to mobile data service. For the purpose of satisfaction on market need, many communication systems should be installed and upgraded based on a mobile wide-band transmission facility. Recently, large part of communication service is based on internet protocol by packet switch techniques and required new technologies such as multimedia processing, QoS achievement, and mobility managememobile communication network such as IS-95A/B and CDMA2000-1X. In this paper, I analyzed the network architecture and service provision methods. in CDMA2000-1X nt. In korea, a CDMA communication technique is standardized for digital mobile communication systems. By using the analysed results, I will extract an efficient method for network evolution and a core technique for next generation mobile communication network.

• Journal of Advanced Navigation Technology
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• v.16 no.6
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• pp.997-1004
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• 2012

In this paper, we propose and implement a signal quality measurement algorithm for CDMA2000 1x terminal. The proposed algorithm is suitable to be implemented in software on a PC-based platform and extract the received signal after carrying out equalization, PN code acquisition and tracking, frequency and phase offset compensation with 4-oversampled input signal. Then, through despreading and demodulation with the extracted signal, the proposed algorithm regenerate the reference signal to be used in measurement. The signal quality is measured using this regenerated signal and the extracted signal.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.2
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• pp.89-95
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• 2003

This paper proposes downlink blocking model and approximation equation using lower bound approximation in order to determine the proper guard band between cdma2000 1X and WCDMA in handover areas. The frequency sharing conditions obtained by the model and approximation equation on blocking probability proposed in the paper, are co-site of base station and guard band higher than 1 MHz. Also, the proposed equation is in the form of Q-function. It is an analytical solution overcoming the drawback of recalculation, belonged to Monte-Carlo technique.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.6
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• pp.296-301
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• 2006

Even though the emergency telecommunication make possible that specialist offers medical care over emergency cases in moving vehicle, we still have many problems in transmitting the image or video of patient over several wireless networks. To alleviate the effect of channel errors on compressed video bit-stream, this paper analyzed the error resilient features of JPEG2000 standard and measured the quality of transmission over noisy wireless channel, CDMA2000 1xEV-DO networks, compared to the features of error resilient tool of MPEG-4. We also proposed the optimum solution of transmitting images over real 3G network using JPEG2000 error resilient tool.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.2
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• pp.65-73
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• 2008

Security layer of the Cdma2000 1x EV-DO is currently completing standard (C.S0024-A v2.0). Accordingly, a hardware security devices, that allows to implementation requirement of the security layer described in standard document, is required to apply security function about data transferred between AT and AN of then Cdma2000 1x EV-DO environment. This paper represents design of hardware device providing EV-DO security with simulation of the security layer protocol via the FPGA platform. The SHA-1 hash algorithm for certification and service of packet data, and the AES, SEED, ARIA algorithms for data encryption are equip in this device. And paper represents implementation of hardware that applies optionally certification and encryption function after executing key-switch using key-switching algorithm.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.327-330
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• 2001

CDMA2000 1x 기반의 무선 인터넷 서비스가 가능해짐에 따라 무선 멀티 미디어 서비스에 대한 수요가 점점 늘어나고 있다. 화상 전화나 VOD 서비스와 같은 실시간 멀티 미디어 서비스에 사용되는 UDP는 현재의 유선과 무선이 혼합된 망에서는 패킷 전송 주기와 패킷의 크기에 따라 매우 다른 성능을 보여준다. 무선 구간에서 전송 효율을 높이기 위해서는 대역폭과 패킷손실률 그리고 채널의 타임슬롯 시간을 고려해 야 한다. 본 논문에서는 CDMA2000 1x 망에서 망 측정을 통하여 실시간 멀티미디어 전송에 적합한 QoS 인자를 추출하여 이를 개선 향상을 위해서 하고 실시간 멀티 미디어 서비스를 위한 대안을 제시하였다.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.8
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• pp.510-516
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• 2005

Rapid advances in telecommunication make emergency telemedicine possible that specialist offers medical care to an emergency case in moving vehicle. Although there were many telemedicine projects delivering the image or video of patient over several wireless networks, none of them considered effective solutions for optimizing video transmission over error-prone environments, such like wireless links. To alleviate the effect of channel errors on compressed video bit-stream, this paper analyzed the error resilient features of MPEG-4 standard and measured the quality of transmitted MPEG-4 encoded video over commercially available CDMA2000 1xEV-DO networks, transmitting different IP packet sizes and RM positions. we propose an error resilient transmission methods for emergency telemedicine over real 3G network.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05b
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• pp.1405-1408
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• 2003

유선망에 최적화되도록 진화해온 TCP 는 GPRS, CDMA2000-1X 등의 무선망에서는 제 성능을 발휘하지 못한다는 것은 이미 널리 알려진 사실이며, 이를 극복하기 위한 방법들이 상당수 제안되었다. 하지만 제안된 연구들의 대부분은 이미 3G 서비스의 링크 계층에서 상당부분 해결된 무선 링크에서의 손실을 혼잡으로 오해하는 TCP 의 문제점을 해결하기 위한 것이다. 본 논문에서는 무선 링크에서의 손실보다는 무선 링크로 인해 야기되는 길고 변화가 심한 전송시간으로 인해 발생하는 TCP 의 문제점을 제시하고, 이를 해결하기 위한 방법을 제안한다. 특히, 본 연구에서는 시뮬레이션이 아닌 실제 CDMA2000-1X 망에서 단말기를 통해 측정된 자료를 기반으로 문제점을 도출하여 기존에 제안된 연구들과 차별화 한다.

• Journal of Korean Institute of Industrial Engineers
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• v.37 no.3
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• pp.229-233
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• 2011

The existing approaches for analyzing the data service capacity of CDMA2000 1X EV-DO (Evolution-Data Only) systems have focused on deriving the maximum number of active customers assuming that the data rates provided to the customers can be determined beforehand. However, we have seen that through real experiment, the data rates actually provided to the customers adaptively change according to the number of active customers. In this paper, we propose new capacity analysis model considering the data rate adaptation. Numerical examples are also presented to obtain the maximum input traffic rates for various values of the length of data burst and the required mean delay bound.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.136-138
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• 2003

인터넷은 이미 대중화되어 있으며, 이러한 인터넷 망을 기초로 한 All-IP 망으로의 망 진화에 대한 논의가 활발하게 진행되고 있다. 또한 현재 상용중인 IPv4에 이동성을 부여한 이동 인터넷(Mobile IPv4)에 대한 연구는 IETF(Internet Engineering Task Force)를 중심으로 활발하게 진행 중에 있으며, 이에 대한 구현 및 개발은 이미 많은 연구단체에서 많은 성과를 보여주고 있다. 본 논문에서는 3세대 이동통신 모델 중의 하나인 CDMA2000 1x 환경에서 기 구현된 Wire-less LAN에서의 이동 인터넷(Mobile IPv4)을 연동하여, 이기종 망(Heterogeneous Network)에서의 이동 인터넷(Mobile Ipv4) 모델을 제시한다. 제시된 이동 인터넷(Mobile IPv4) 프로토콜은 Layer-2망으로서 Wireless LAN과 CDMA2000 1x을 모두 사용하며, 하부 망(Layer-2 Network)의 변화에 능동적으로 반응하여, 통신을 유지한다.