• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.5
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• pp.907-915
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• 2003

A very efficient packet transmission scheme is needed in the radio environment where radio resource is insufficient as compared with the environment of the wired communication. In general, dual mode packet transmission scheme is used broadly. Packets are transmitted through the dedicated or common chamois according to a switching criterion. The general criteria are the length and generation frequency of packet, that is, large and frequent packets are transmitted using a dedicated channel and small and infrequent packets are transmitted using a common channel. The performance of dual mode packet transmission scheme is closely related to the switching criteria. However, it is very difficult to find the optimal switching point because that is not fixed but variable according to the environment such as traffic load, length of generated packets, and the number of channels. In this paper, a new scheme for the dual mode packet transmission scheme using a dynamic switching threshold is proposed where the switching threshold is not fixed but variable according to the network environment. The performance of the proposed method is analyzed using a simulation. From the simulation results, it is shown that the performance of the proposed scheme is not very influenced by the network environment unlike the conventional dual mode packet transmission scheme.

• The Journal of the Korea Contents Association
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• v.5 no.1
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• pp.147-155
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• 2005

In this paper, communication channels for the transmission of multimedia packets are modeled and evaluated. The multimedia packet traffic characterized by on-off and MMPP process for voice and data, respectively, dynamic channel allocation, queueing of data packets due to unavailability of channels and dropping of queued data packets over timeout, and guard channel for voice packets are modeled. The performance indices adopted in the evaluation of SRN model includes blocking and dropping probabilities. The SRN uses rewards concepts instead of the complicate numerical analysis required for the Markov chain. It is shown that our SRN modeling techniques provide an easier way to carry out performance analysis.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.975-978
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• 2010

그룹통신에서의 작업자 간에 긴밀한 통신을 필요로 하는 경우에 기존의 무전기나 주파수 공용통신은 음성 품질이 매우 열악하여 통신 신뢰성이 매우 낮다. 이러한 문제를 해결하기 위해 그룹통신에서 VoIP를 활용하는 것이 요구된다. VoIP를 이용할 경우 20ms정도의 짧은 주기로 인하여 패킷마다의 헤더로 인한 오버헤드가 발생하는데 이를 해결하기 위해 그룹통신에서의 패킷번들링이 요구된다. 따라서 본 연구에서는 패킷번들링을 적용한 상태에서 VoIP를 이용한 그룹통신 성능분석을 하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.590-593
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• 2005

In this paper, it is analyzed a transmission time of ACL Packet in bluetooth wireless link. In order for segment to improve the transfer capability in bluetooth system, it is fragmented in TCP total messages that are coming down from upper layer and then the packets are sent one at time in baseband. And it is studied that transmission time for bluetooth wireless link according to DM1, DM3 or DM5 packet type in bluetooth piconet environment. From the results, we were able to obtain ACL packet transmission time, optimal TCP packet size and DM packet size.

• The KIPS Transactions:PartC
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• v.13C no.7 s.110
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• pp.813-820
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• 2006

The advance of computer and communication technologies enables the embedded systems to be equipped with the network communication interfaces. Their appearance in network leads to security issues on the embedded systems. An easy way to overcome the security problem is to adopt the packet filter that is implemented in the general computer systems. However, general packet filters designed for host computers are not suitable to embedded systems because of their complexity. In this paper, we propose a lightweight packet filter for embedded systems. The lightweight packet filter is implemented in the kernel code. And we have installed a Web-GUI interface for user to easily set the filtering policies at remote space. The experimental results show that the proposed packet filter decreases the packet delivery time compared to the packet filter designed for host computers and it is comparable to the systems without packet filter.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1998.11a
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• pp.549-552
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• 1998

본 논문에서는 wavelet 패킷의 직교성을 이용한 새로운 다중 통신 시스템을 구성하고 그 특성을 분석하였다. 유한에너지 신호공간 L$^2$(R)로부터 부분공간으로 신호를 분해할 수 있는 MRA(Multiresolution Analysis)의 기본개념과 이를 이용한 wavelet와 QMF(Quadrature Mirror Filter)와의 관계를 검토하였다. MRA의 개념을 보다 일반화한 신호의 wavelet 패킷 변환과 역변환을 실현하기 위한 알고리즘을 고찰하고 MRF(Multirate Filter Bank)를 이용하여 다중화 시스템을 설계하였다. 제안된 시스템은 구성이 간단하며 최대 이용자의 수와 정보 데이터의 전송율에 대한 유연성을 기대할 수 있음을 보였다.

• Journal of KIISE:Information Networking
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• v.32 no.3
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• pp.404-414
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• 2005

In the packet data network systems beyond 3G, the service quality of current users is affected by traffic load due to the packet burstiness. There also exists a hot cell problem, a well-known problem of cellular systems, caused by traffic centraliBation. Hot cell problem is one of the major reasons of degrading system performance because hot cell increases the call drop rate without fully utilization of system resource. Therefore, it is very important to distribute the traffic on the several neighboring cells so that system uses its resource effectively and maintains the quality of service. In this paper, we propose the adaptive handoff algorithms for distributing traffic in the packet data network systems. In addition, we propose a new load estimation method with MAC state diagram suitable for packet data network systems. Through the simulation results, we could find that proposed algorithm is able to improve efficiency of system resource and to assure the service quality of users through traffic distribution.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.14 no.5
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• pp.521-530
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• 1989

Broadband ATM(Asynchronous Transfer Mode) networking techniques based on lightwave technology and high speed integrated circuits appear to be the choice of transport technology for broadband ISDN. Among other problems, the issue of video transport over broadband packet(ATM) networks still requries further investigation. In this paper, the problems of transporting video signals over a broaband packet network are investigated together with possible solutions. In particular, clock recovery packet loss compensation and transport technique based on hierarchical video coding scheme are described in detail. This would allow efficient bandwidth sharing and minimum degradation in video quality.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.580-582
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• 2012

네트워크 기반의 이동성 관리 프로토콜인 PMIPv6(Proxy Mobile IPv6)에서 방송이나 비디오 스트리밍과 같은 서비스를 제공할 때 멀티캐스트 방식을 이용하여 데이터 패킷을 전송하는 기법이 제안되었다. 제안되었던 기법은 MN(Mobile Node)이 핸드오버할 때 nMAG(new Mobile Access Gateway) 내에 같은 멀티캐스트 멤버인 또 다른 MN이 존재할 경우를 고려하지 않았다. 본 논문에서는 같은 멀티캐스트 멤버인 MN이 존재할 경우 버퍼링된 패킷들의 중복 전송을 막는 기법에 대해 제안한다. 이 후 MN이 nMAG로 핸드오버했을 때 같은 멀티캐스트 멤버를 가진다면 버퍼링된 패킷을 현재 핸드오버한 MN에만 포워딩하여 중복 전송되는 것을 방지한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.93-94
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• 2019

최근 클라우드 서비스가 급속도로 등장하고 있으며 이러한 서비스는 기존의 IP 네트워크를 사용한다. 기존의 네트워크는 댜앙한 트래픽 패턴에 대해 비 효율적이고 복잡한 구조를 가지고 있는 문제가 있다. 이러한 문제를 해결하기 위해 SDN 기술이 도입되어 널리 보급되고 있다. 클라우드 서비스 센터에서는 SDN 기술을 채택하여 많은 성과를 이루고 있지만 패킷 스케줄링 같은 분야는 아직 초기단계이다. 또한 SDN 환경에서 각 네트워크 노드로부터 데이터와 관련된 스위치에 효율적으로 전달하는 것이 중요한 이슈로 부각되고 있으며 본 논문에서는 큐잉이론을 적용한 패킷 스케줄링 기법을 제안한다.