• 제목/요약/키워드: Optical Network switch

검색결과 48건 처리시간 0.02초

Performance Analysis of Chained Amplifier Systems for Metropolitan Optical Network Applications

  • Lee, Jong-Hyung;Choi, Byeong-Yoon
    • Journal of information and communication convergence engineering
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    • 제7권3호
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    • pp.377-382
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    • 2009
  • In this paper, theoretical analysis for metropolitan optical networks is performed. First, analytical optical SNR is derived assuming each node consists of an EDFA, an optical filter, an optical switch, and a VOA, and then the relationship between OSNR and BER is studied. In a metropolitan optical network, an optical signal can be dropped to deliver data, and we also studied the effect of drop loss on system performance. When the drop loss is relatively small, the receiver structure of the node can be treated as a preamplifier receiver which is widely used in long-haul systems. In that case, ASE noise from EDFAs is the dominant noise source in the receiver. However, system performance is relatively insensitive to OSNR when the drop loss is significant because of the noise sources in the receiver (thermal and shot noise).

광 네트워크 스위치 응용을 위한 RSFQ Switch의 회로 설계 및 시뮬레이션 (Circuit Design and Simulation Study of an RSFQ Switch Element for Optical Network Switch Applications)

  • 홍희송;정구락;박종혁;임해용;장영록;강준희;한택상
    • Progress in Superconductivity
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    • 제5권1호
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    • pp.13-16
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    • 2003
  • In this work, we have studied about an RSFQ (Rapid Single Flux Quantum) switch element. The circuit was designed, simulated, and laid out for mask fabrication. The switch cell was composed of a D flip-flop, a splitter, a confluence buffer, and a switch core. The switch core determined if the input data could pass to the output. “On” and o“off” controls in the switch core could be possible by utilizing an RS flip-flop. When a control pulse was input to the “on” port, the RS flip-flop was in the set state and passed the input pulses to the output port. When a pulse was input to the “off” port, the RS flip-flop was in the reset state and prevented the input pulses from transferring to the output port. We simulated and optimized the switch element circuit by using Xic, WRspice, and Julia. The minimum circuit margins in simulations were more than $\pm$20%. We also performed the mask layout of the circuit by using Xic and Lmeter.

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Comparative Performance Study of WDM Packet Switch for Different Traffic Arrival Approach

  • Reza, Ahmed Galib;Lim, Hyo-Taek
    • Journal of information and communication convergence engineering
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    • 제9권5호
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    • pp.551-555
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    • 2011
  • Optical packet switching is a promising technology, which can integrate both data and optical network. In this paper, we present a comparative study of various traffic arrival approaches in WDM packet switches. The comparison is made based on packet loss rate and average delay under uniform and self-similar Pareto traffic. Computer simulations are performed in order to obtain the switch performance metrics. Study shows that burstiness of data traffic has a strong negative impact in the performance of WDM packet switches.

MEMS를 이용한 OXC 스위치 패브릭 구조 및 제어 (OXC switch Fabric Structure and Control using MEMS)

  • 이상화;김병휘;김광준;박혁;이왕주
    • 한국광학회:학술대회논문집
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    • 한국광학회 2002년도 하계학술발표회
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    • pp.258-259
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    • 2002
  • 광회선 분배 시스템(OXC)은 전광통신망(Optical Transport Network)에서 광신호 간 연결을 원격으로 설정해 줄 수 있는 노드(Optical Network Element)이다. OXC는 다수의 입력/출력 링크를 가지며 하나의 입력/출력 링크에는 다수의 파장 다중된 광신호 채널이 존재한다. OXC는 하나의 입력 링크를 통하여 입력되는 다수의 파장 채널을 서로 다른 출력 링크로 연결해 주거나, 다수의 입력 링크로부터 입력되는 파장채널을 하나의 출력 링크로 연곁해 줄 수 있는 optical grooming 기능을 수행한다. 또한 자국에서 광신호를 Add/Drop할 수 있는 기능을 가질 수 있다. (중략)

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광 버스트 스위치를 위한 새로운 충돌 해결 알고리즘 (New Contention Resolution algorithm for Optical Burst Switch)

  • 정명순;엄진섭
    • 한국통신학회논문지
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    • 제29권12A호
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    • pp.1285-1290
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    • 2004
  • 본 논문에서는 광 버스트 네트워크 내의 버스트 충돌을 해결하기 위한 새로운 알고리즘을 제안하였다. 제안된 알고리즘은 파장 변환(conversion), 경로 변경(deflection), 분리(segmentation), 광섬유 버퍼링을 흔합하여 광 스위치에 적용한 것이다. 제안된 충돌 해결 알고리즘의 성능은 ns(network simulator)-2를 이용하여 분석하였다. 시뮬레이션에 사용한 네트워크 토폴로지는 한국의 기간망을 가정하였고 이를 기반으로 다양한 네트워크 트래픽 조건에서 성능 지표(버림 확률, 전파 지연)의 개선을 보였다.

광 인터넷의 개방형 인터페이스를 위한 병렬형 연동 모델의 특성 (Characteristics of a Parallel Interworking Model for Open Interface of Optical Internet)

  • 김춘희;백현규;차영욱;최준균
    • 한국정보과학회논문지:정보통신
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    • 제29권4호
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    • pp.405-411
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    • 2002
  • 광 인터넷에서 광 전달망과 제어평면의 분리를 실현하는 개방형 인터페이스에 대한 연구는 OIF의 ISI, ITU-T ASON의 CCI 그리고 IETF의 광 스위칭을 위한 GSMP 확장 등이 있다. 이러한 개방형 인터페이스 기술들은 망에서의 다양한 융통성을 제공하는 반면에 전통적인 스위치-대-스위치 연결 설정에 비하여 지연이 길다. 본 논문에서는 광 인터넷의 개방형 인터페이스에서 연결 설정 지연을 줄이기 위하여 병렬형 연동 모델을 채택 한다. 병렬형 연동 모델에서는 네트워크 상태에 대한 스위치 제어기의 캐쉴 능력을 기반으로 연결 설정을 위한 신호 프로토콜과 GSMP 프로토콜 사이의 연동 절차를 병렬로 수행한다. 시뮬레이션을 통하여 본 논문에서 채택한 병렬형 연동 모델과 기존의 순차형 연동 모델에 대한 연결 설정 지연과 완료율을 비교 분석하였다. 시뮬레이션 결과 두 모델이 완료율 면에서는 거의 일치하며, 연결 설정 지연 면에서는 병렬형 모델이 순차형 모델에 비하여 평균 30% 향상됨을 알 수 있었다.

광 버스트 스위칭을 위한 광 교환기에서의 다중 누화고장 진단기법 (Diagnosis of Multiple Crosstalk-Faults in Optical Cross Connects for Optical Burst Switching)

  • 김영재;조광현
    • 제어로봇시스템학회논문지
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    • 제9권3호
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    • pp.251-258
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    • 2003
  • Optical Switching Matrix (OSM) or Optical Multistage Interconnection Networks (OMINs) comprising photonic switches have been studied extensively as important interconnecting blocks for Optical Cross Connects (OXC) based on Optical Burst Switching (OBS). A basic element of photonic switching networks is a 2$\times$2 directional coupler with two inputs and two outputs. This paper is concerned with the diagnosis of multiple crosstalk-faults in OSM. As the network size becomes larger in these days, the conventional diagnosis methods based on tests and simulation become inefficient, or even more impractical. We propose a simple and easily implementable algorithm for detection and isolation of the multiple crosstalk-faults in OSM. Specifically. we develop an algorithm for isolation of the source fault in switching elements whenever the multiple crosstalk-faults arc detected in OSM. The proposed algorithm is illustrated by an example of 16$\times$16 OSM.

Passive Star 토플로지와 WDM을 사용한 다중채널 광섬유 LAN을 위한 Multiple Access 르로토콜 (Multiple Access Protocols for a Multichannel Optical Fibre Local Area Network Using a Passive Star Topology and WDM)

  • 이형우
    • 전자공학회논문지A
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    • 제32A권9호
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    • pp.1184-1201
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    • 1995
  • Two multiple access protocols are proposed for a multichannel WDM optical fibre local area network or metropolitan area network in which users are interconnected using a passive star topology. Each user has a single tunable transmitter and a single tunable receiver. A transmitter sends a control packet before its data packet transmission so that its intended receivers can tune to the proper data channel wavelength. The maximum throughput of the proposed protocols are independent of the effective normalized propagation delay which may include the transmitter and receiver tuning times and the processing delays. The maximum throughputs of the protocols are analyzed and compared with those of the existing ones by numerical examples. The message delay of the R- Aloha/synchronous N-server switch protocol which is suitable for the queued users is also analyzed.

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광 다단계 상호연결망의 단일 누화고장에 대한 해석적 고장진단 기법 (Analytical Diagnosis of Single Crosstalk-Fault in Optical Multistage Interconnection Networks)

  • 김영재;조광현
    • 제어로봇시스템학회논문지
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    • 제8권3호
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    • pp.256-263
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    • 2002
  • Optical Multistage Interconnection Networks(OMINs) comprising photonic switches have been studied extensively as important interconnecting building blocks for communication networks and parallel computing systems. A basic element of photonic switching networks is a 2$\times$2 directional coupler with two inputs and two outputs. This paper is concerned with the diagnosis of cross-talk-faults in OMINs. As the size of today's network becomes very large, the conventional diagnosis methods based on tests and simulation have become inefficient, or even more, impractical. In this paper, we propose a simple and easily implementable algorithm for detection and isolation of the single crosstalk-fault in OMINs. Specifically, we develope an algorithm fur the isolation of the source fault in switching elements whenever the single crosstalk-fault is detected in OMINS. The proposed algorithm is illustrated by an example of 16$\times$16 banyan network.

지중 배전계통 적용을 위한 광복합 케이블 실시간 감시시스템 개선 (An Improvement of Optical Fiber Composite Power Cable On-Line Monitoring System for Underground Distribution Network)

  • 조진태;김주용;이학주;박중성
    • 조명전기설비학회논문지
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    • 제26권7호
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    • pp.77-83
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    • 2012
  • Since power system is switching to smart grid, on-line monitoring technology has become necessary for underground distribution power cable. Therefore, the application of DTS(Distributed Temperature Sensing) technology using OFCPC(Optical Fiber Composite Power Cable) capable of monitoring underground distribution power cables has been developed. These can bring about reductions in faults and increases in operating capacity of underground distribution system. To date, the test-bed of optical fiber composite power cable on-line monitoring system has been constructed. Then, matters to be improved have been drawn through verification experiments. This paper presents the improvement and experiment results of the optical fiber composite power cable on-line monitoring system to apply to underground distribution lines in the field.