• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.412-414
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• 2005

Multimeda service is very big capacity and use not a little network for provide cots. Because in paper introduce new method adaptive to merit of Unicast and Multicast. Propose method service possibility that now Multicast have merit which live broadcasting and Unicast have merit which can provide individually customer manage and good quality by data statistics. And network use to efficient

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.843-846
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• 2003

In this paper, we have analyzed algorithm of physical layer, data link layer and MAC layer of Out-Of-Band (OOB) specified in the OpenCabl $e^{TM}$SCTE-55-2 2002$^{[3]}$ and designed architecture of the OOB processor. The OOB processor performs fundamental multiple access control for the OOB channel and extracts session key information from a EMM packet for descrambling MPEG-2 streams. In this paper, we have implemented a prototype board for the DVS167 OOB processor and verified it.t.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.61-64
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• 2003

GPRS is designed for transmitting packet data and supposed to take its radio resource form the pool of channels unused by GSM voice services. In this paper, The GPRS and GSM circuit switched services share the same radio resource. Whenever a channel is not used by circuit switched services, it may be utilized by GPRS. In this paper, the main aim is performance and comparison resource management policies with channel de-allocation in GPRS network. Three resource management policies is voice priority, R-reservation, dynamic reservation.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.133-136
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• 2003

In this paper, we propose a multicast routing protocol for the seamless delivery of multicast data to mobile hosts through the optimal route in IP based mobile networks. The proposed multicast routing protocol is a hybrid method employing the merits of the bi-directional tunneling and the remote subscription by considering the mobility of mobile hosts. The proposed protocol satisfies the bound of end-to-end delay and supports the seamless handoff. The simulation results show that the proposed protocol has better performance in the number of multicast tree reconstruction and tunneling length and packet loss time than the previous protocols.

• Proceedings of the IEEK Conference
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• 2002.06c
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• pp.235-238
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• 2002

This paper presents a remote mobile robot system that transmits streaming video and audio over the lossy packet networks such as (Wireless) LAN. The error resilient video and audio packets are transmitted on the RTP/UDPfP Protocol stack. The mobile robot can be accessed by a certified user from the remoted area. Thus, the movement of mobile robot can be controlled by the operator observing the working surroundings.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.8
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• pp.1970-1975
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• 1996

The characteristics of data traffic on the Ethernet LAN are investigated on the basis of measurements. The analysis on the arrival pattern of packets on the network is found not to be a Poission process but to be Weibull distributions. An analysis of network traffic, packet arrivals are found to exhibit a 'source locality'. It is observed that file transfers are reponsible for about 92% of the traffic on the network. Our results will be useful for modelling purposes.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1997.06a
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• pp.49-54
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• 1997

For the purpose of a flexible coded video transmission over a heterogeneous network, we propose a new packetization method for coded video data. The proposed method achieves small degradation of coded picture quality in case of packet discard at the network node and does not require heavy processing load for bitrate control operation. Computer simulation results show that the bitrate reduction from 384 kb/s to 192 kb/s does not cause severe degradation in picture quality.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.673-675
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• 2001

IMT-2000망 핵심기술은 mobile IP를 이용하는 북미의 3G packet data system과 GSM망과 연계를 하는 유럽의 GPRS로 구분할 수 있다. Mobile IP상에서는 RADIUS나 DIAMETER같은 AAA 서버가 다이얼 업 컴퓨터의 인증, 허가 서비스를 제공하기 위해 사용되고 있는데, 이것은 MN에게 매우 중요하다. Mobile IP는 MN과 HA간에 강력한 인증을 요구하기 때문이다. 본 논문에서는 이러한 IMT-2000 환경에서 고려되고 있는 Smooth Handoff 지원 방안에 관하여 논한다.

• IEMEK Journal of Embedded Systems and Applications
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• v.15 no.2
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• pp.103-109
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• 2020

This paper finds solutions for using ZigBee in wireless networked control system (WNCS). The round trip time delay and packet loss rate of the WNCS are measured. On the basis of these measured data, a playback buffer is used to solve the variable time delay in WNCS, and a Smith predictor is introduced to compensate for the time delay. The WNCS was able to be actually constructed to perform DC motor position control with 40 Hz sampling frequency.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10c
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• pp.97-99
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• 2003

최근 무선망 수요가 급증함에 따라 무선단말기의 전원효율을 높이고 망의 오버헤드를 줄이는 한편, 단말의 위치추적을 위하여 페이징(paging) 기법이 등장하게 되었다. IP 패킷 단말의 이동성과 함께 효율적인 페이징 기법이 차세대 무선망 기술의 핵심 이슈로 떠오르고 있다. 이에 본 논문은 국내의 차세대 IP 패킷 무선망으로써 연구되고 있는 HPi(High­speed Portable internet)망을 위한 페이징 프로토콜 및 페이징 영역 구조를 제안한다.