• Title/Summary/Keyword: 멀티링크

Search Result 481, Processing Time 0.026 seconds

Extended Multi-level Inverter with DC-link Switches (DC 링크 스위치를 갖는 확장형 멀티레벨 인버터)

  • Sun, Ho-Dong;Park, Jong-Hyung;Cha, Honnyong;Kim, Heung-Geun;Chun, Tae-Won;Nho, Eui-Cheol
    • Proceedings of the KIPE Conference
    • /
    • 2011.07a
    • /
    • pp.374-375
    • /
    • 2011
  • 본 논문은 역률 제어가 가능한 개선된 DC 링크 스위치를 갖는 멀티레벨 인버터를 제안한다. DC 링크단에 다이오드 대신 전력용 스위치를 연결함으로서 역률을 제어할 수 있게 하였다. 또한 전압레벨 확장에 있어서 추가적인 전력용 소자를 최소화한 방식을 제안한다. 제안한 방식은 전압 레벨확장에 있어 전력용 소자를 적게 사용함으로서 신뢰성을 높고, 손실을 작으며, 비용이 저렴해지는 이점을 갖는다. 제안된 토폴로지의 타당성은 시뮬레이션을 통하여 검증하였다.

  • PDF

Experimentation and Analysis of SCTP Throughput by MuIti-homing (멀티홈잉 기반 SCTP 성능 실험 및 비교 분석)

  • Koh Seok-Joo;Ha Jong-Shik
    • The KIPS Transactions:PartC
    • /
    • v.13C no.2 s.105
    • /
    • pp.235-240
    • /
    • 2006
  • Stream Control Transmission Protocol (SCTP) provides the multi-homing feature, which allows each SCTP endpoint to use two or more IP addresses for data transmission. In this paper, the SCTP multi-homing feature is experimented and analyzed in terms of throughput over Linux platforms based on the NISTNET network emulator. We perform the experimental analysis of SCTP throughputs by SCTP multi-homing for the various network conditions: different packet loss rates, network bandwidths, and transmission delays. From the experimental results, it is shown that the SCTP multi-homing gives much better throughout gun over the SCTP single-homing case in the networks with a high packet loss rate. In the meantime, the other factors including network bandwidth and transmission delay do not seem to give a significant impact on the performance of the SCTP multi-homing.

Design and Construction of Fiber Optical Link Application System for Multi-Video Audio Data Transmission (광MVAD(Multi-Video Audio Data)쌍방향 다채널링크시스템 설계)

  • Lee, Jae-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.10 no.10
    • /
    • pp.2691-2695
    • /
    • 2009
  • Nowadays Fiber optical communication systems have limitless bandwidth and can be used for transmitting various multimedia data with in real time. It is necessary to construct integrated service systems that can be used in our society whole to communicate multimedia data such as text, image, audio and video data in fiber optic communication systems. In this paper, we have designed and constructed the fiber optical link application system for multi-video/audio data transmission using only one core optical cable upgrading previous fiber optical communication systems based on WDM (Wavelength Division Multiplexer). Using the proposed fiber optical link application system enables us to managing fiber optical communication systems with only one core optical cable using WDM (Wavelength Division Multiplexer) and DEWDM/Wavelength splitter.

A Fair Queuing Algorithm to Reduce Energy Consumption in Wireless Channels (무선 채널의 에너지 소비를 줄이기 위한 공평 큐잉 알고리즘)

  • Kim, Tae-Joon
    • Journal of Korea Multimedia Society
    • /
    • v.10 no.7
    • /
    • pp.893-901
    • /
    • 2007
  • Since real-time multimedia applications requiring duality-of-service guarantees are spreading over mobile and wireless networks, energy efficiency in wireless channels is becoming more important. Energy consumption in the channels can be reduced with decreasing the rate of scheduler's outgoing link by means of Dynamic Modulation Scaling (DMS). This paper proposes a fair queuing algorithm, termed Rate Efficient Fair Queuing (REFQ), in order to reduce the outgoing link's rate, which is based on the Latency-Optimized Fair Queuing algorithm developed to enhance Weighted Fair Queuing (WFQ). The performance evaluation result shows that REFQ does decrease the link rate by up to 35% in comparison with that in WFQ, which results in reducing the energy consumption by up to 90% when applied to the DMS based radio modem.

  • PDF

Logical Link-Based Multicasting Services in Ethernet Passive Optical Networks (이더넷 수동형 광가입자망에서 논리적 링크 기반의 멀티캐스팅 서비스)

  • Choi Su-il
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.30 no.11B
    • /
    • pp.722-729
    • /
    • 2005
  • Ethernet passive optical networks (EPONs) are an emerging access network technology which has a point-to-multipoint topology. EPONs operate point-to-multipoint in the OLT-ONU direction, and point-to-point in the ONU-OLT direction. To support point-to-point emulation and shared LAM emulation, EPONs use multi-point control protocol (MPCP). The MPCP uses logical link identification (LLID) field for frame tagging and filtering between the OLT and ONUs. In this paper, I propose logical-group identification (LGID) for logical link-based multicasting or VLAN services in EPONs. Using LGID with new frame tagging and filtering rules, EPONs support differentiated multimedia broadcasting or multicasting services. Additionally, EPONs can support logical link-based VLAN services that divides ONUs into several subsets.

Downlink SINR Analysis of Multihop Cellular Networks according to Relay Positions (멀티홉 셀룰러 네트워크에서 릴레이 위치에 따른 하향링크 SINR 분석)

  • Cho, Sung-Hyun;Moon, Sung-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.35 no.6A
    • /
    • pp.594-599
    • /
    • 2010
  • This paper studies the effect of the deployment position of the relay stations on the downlink signal-to-interference-noise-ratio (SINR) in multihop cellular networks. Two different relay deployment scenarios are considered where relay stations are located either inside cells or on the boundary among adjacent cells. The fundamental contribution is to compare fairly the average SINR between two scenarios with the proposed relay modeling framework that includes multi-cell geometries and inter-cell interferences. The mathematical results show that the SINR increases when relay stations are located inside cells because of higher received signal power.

Improving Streaming Performance using Link Characteristic Information in the Context of SIP Mobility (SIP Mobility에서 링크특성정보를 이용한 스트리밍 성능 개선)

  • Lee, Min-Ho;Park, Soo-Hong;Jang, Jeong-Rok;Cho, Sang-Wook
    • Proceedings of the KIEE Conference
    • /
    • 2008.10b
    • /
    • pp.501-502
    • /
    • 2008
  • 모바일 단말이 이종네트워크 환경에서 멀티미디어 데이터를 스트리밍 수신받으며 이동할 때, 특성이 다른 링크로 옮겨감에 따라 스트림의 전송률이 링크의 적정 대역폭을 초과하여 정상적인 전송이 되지 않거나 링크의 적정 대역폭을 미달하여 효율적인 전송이 되지 않을 수 있다. 본 논문에서는 SIP Mobility상황에서의 링크특성 정보 저달 방법을 고안하고, 전달받은 링크특성 정보를 통한 전송 조절 방법을 제안한다. 실제 RTP패킷 전송 실험을 통하여 스트리밍 전송 성능이 개선됨을 보인다.

  • PDF

Implementation and Performance Evaluation of Link Characteristic Information Delivery Mechanism in the Context of Mobile IPv6 (Mobile IPv6 에서의 링크 특성 정보 전달 메커니즘의 구현 및 성능 평가)

  • Hyun, Do-Won;Lee, Min-Ho;Park, Soo-Hong;Jang, Ju-Wook
    • Proceedings of the Korea Information Processing Society Conference
    • /
    • 2007.11a
    • /
    • pp.707-710
    • /
    • 2007
  • 모바일 단말이 이종네트워크 환경에서 멀티미디어 데이터를 스트리밍 수신 받으며 이동하는 경우, 특성이 다른 링크로 옮겨감에 따라 링크의 적정 대역폭에 맞지 않은 스트림 전송률 때문에 전송 성능이 떨어진다. 본 논문은 Mobile IPv6 에서의 링크 특성 정보 전달방법을 이용하여 스트리밍 전송 성능을 높일 수 있음을 보인다. 이를 위해서 실제로 링크 특성 정보 전달 방법이 적용된 Mobile IPv6 테스트 베드를 설계하여 MN 에 링크 특성 추출 기능을 구현하였고, CN 에 데이터 전송율을 조절할 수 있는 UDP 스트리밍 서버 기능을 구현하였다. 스트리밍 데이터를 수신하는 MN 이이종 네트워크 환경간을 핸드오버할 때에 전송 성능이 향상됨을 실험을 통하여 보인다.

A Study on Implementation for Web Search Program in Specific Web Site (특정 사이트내의 검색 프로그램 구현에 관한 연구)

  • Jang, Doc-Sung;Gu, Se-Wan
    • Proceedings of the Korea Information Processing Society Conference
    • /
    • 2002.04b
    • /
    • pp.1243-1246
    • /
    • 2002
  • 본 논문은 검색엔진을 이용하여 대상 웹사이트의 링크 사이트 전체를 수집하고, 각 링크 사이트의 페이지를 인덱싱하여 데이터베이스화하는데, 특히 가장 최신의 페이지를 분류하여 시간에 의해 검색단어의 정확도가 가려지는 경우, 이를 이용할 수 있도록 하였다. 본 논문은 검색엔진에 의해 검색 서비스를 제공하는 기본적인 웹 로봇의 구현에 대한 연구이며, 웹 로봇의 역할은 크게 링크 사이트를 수집하는 것 이외에 제목, 메타태그, 멀티미디어 다운로드등의 역할들을 수행하며 이를 인덱싱 하여 데이터베이스화한다.

  • PDF

Hybrid ARQ Techniques for Multimedia Services (멀티미디어 서비스를 위한 H-ARQ 기법 성능 분석)

  • Cho, Seong-Chul;Suh, Hee-Seok
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.20 no.10
    • /
    • pp.135-140
    • /
    • 2006
  • In this paper, we present hybrid ARQ techniques to improve the throughput performance in high speed packet transmission such as Internet or multimedia services. In order to evaluate the performance of the three different types of hybrid ARQ schemes, systemized link level simulations based on WWW traffic model are considered. In this paper, we also consider the simulated performance for an average link throughput and a normalized packet delay to compare the hybrid ARQ with link adaptation scheme in GPRS.