• Title/Summary/Keyword: wavelength multiplexing

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Lightpaths Routing for Single Link Failure Survivability in IP-over-WDM Networks

  • Javed, Muhammad;Thulasiraman, Krishnaiyan;Xue, Guoliang(Larry)
    • Journal of Communications and Networks
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    • v.9 no.4
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    • pp.394-401
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    • 2007
  • High speed all optical network is a viable option to satisfy the exponential growth of internet usage in the recent years. Optical networks offer very high bit rates and, by employing technologies like internet protocol over wavelength division multiplexing(IP-over-WDM), these high bit rates can be effectively utilized. However, failure of a network component, carrying such high speed data traffic can result in enormous loss of data in a few seconds and persistence of a failure can severely degrade the performance of the entire network. Designing IP-over-WDM networks, which can withstand failures, has been subject of considerable interest in the research community recently. Most of the research is focused on the failure of optical links in the network. This paper addresses the problem of designing IP-over-WDM networks that do not suffer service degradation in case of a single link failure. The paper proposes an approach based on the framework provided by a recent paper by M. Kurant and P. Thiran. The proposed approach can be used to design large survivable IP-over-WDM networks.

Transmission Performance of 40 Gb/s PM Duobinary Signals due to Fiber Nonlinearities in DWDM Systems Using VSB Filtering Techniques

  • Jang, Ho-Deok;Kim, Kyoung-Soo;Lee, Jae-Hoon;Jeong, Ji-Chai
    • Journal of the Optical Society of Korea
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    • v.13 no.3
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    • pp.354-360
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    • 2009
  • We investigate theoretically the tolerance of 40 Gbps phase-modulated (PM) duobinary signals using a vestigial sideband (VSB) filter on impairments which occurred in dense wavelength-division multiplexing (DWDM) systems, compared to the conventional duobinary signals. Our simulation results show that PM duobinary signals can't have the gain on the spectral efficiency achieved by utilizing the VSB filtering technique. In order to increase the spectral efficiency, they indispensably require to be transmitted at the optimum bandwidth of multiplexer (MUX) and demultiplexer (DEMUX) since they are susceptible to inter-channel crosstalk. It is also shown that the PM duobinary modulation format has a large tolerance on self-phase modulation (SPM) and cross-phase modulation (XPM) under the condition which MUX and DEMUX have been tuned at an optimum bandwidth; it has 1.2 dB power penalty at the fiber launching power (FLP) of 15 dBm and the channel spacing of 50 GHz.

A Study on a Design of the Optical Transceiver Channel Unit (광 송수신기채널 유닛 설계에 관한 연구)

  • Hur, Chang-Wu;Yeom, Jin-Su
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.7
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    • pp.1354-1358
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    • 2007
  • Nowaday, the wideband multimedia service, high speed and great capacity internet service etc. are increasing, so the network construction with the base of optical subscriber network is necessary. As efficient and economic optical subscriber networks are developed, so efficient network construction is possible. The most technology of them is WDM(Wavelength Division Multiplexing)-PON technology of ONU(Optical Network Unit) jointing method using PON(Passive Optical Network). In this paper, we have studied on a method for automatic optimization of data modulation current as optical power when the data is transmitted.

Optical VSB Filtering of 12.5-GHz Spaced 64 × 12.4 Gb/s WDM Channels Using a Pair of Fabry-Perot Filters

  • Batsuren, Budsuren;Kim, Hyung Hwan;Eom, Chan Yong;Choi, Jin Joo;Lee, Jae Seung
    • Journal of the Optical Society of Korea
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    • v.17 no.1
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    • pp.63-67
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    • 2013
  • We perform an optical vestigial sideband (VSB) filtering using a pair of Fabry-Perot (FP) filters. The transmittance curve of each FP filter is made to have sharp skirts using an offset between input and output coupling fibers. Moreover, the accurate periodicity of FP filters in the optical frequency domain enables the simultaneous VSB filtering of a large number of optical channels. With this VSB filtering technique, we transmit 12.5-GHz spaced $64{\times}12.4-Gb/s$ wavelength-division-multiplexing channels over a single-mode fiber up to 150 km without any dispersion compensations. When the channel spacing is reduced to 10 GHz, we achieve the spectral efficiency of 1 bit/s/Hz in conventional optical intensity modulation systems up to 125 km.

Measurement of Exhaust Gas Concentration using Wavelength Modulation Spectroscopy (파장 변조 기법을 이용한 연소배기 가스의 계측)

  • Kim, Dong-Hyuck;Kim, Se-Won;Shin, Myung-Chul;Kim, Yong-Mo
    • 한국연소학회:학술대회논문집
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    • 2006.10a
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    • pp.97-103
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    • 2006
  • This work forcus on the development of gas sensor that measure the concentrations of exhaust gas using diode laser. Each diode laser for exhaust gas measurement is set to work at near-IR using both DA and WMS methods. Also use of fiber-coupled optical elements makes such a sensor rugged and easy to align. On-line data acquisition and processing can be performed with a PC running LabVIEW software, and absorption signals are measured simultaneously by multiplexing method. Finally, It were experimentally compared WMS (Wavelength Modulation Spectroscopy) with DA (Direct Absorption) for the accuracy.

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Protecting Multicast Sessions in WDM Networks with Sparse-Splitting Constraints

  • Wang, Xiong;Wang, Sheng;Li, Lemin
    • ETRI Journal
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    • v.29 no.4
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    • pp.524-526
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    • 2007
  • In this letter, we study the multicast protection problem in sparse-splitting wavelength-division multiplexing (WDM) optical network, and propose a novel multicast protection algorithm called the shared source-leaf path-based protection (SLPP) algorithm. Unlike the proposals in previous studies, the backup paths derived by SLPP can share wavelength with the primary tree in sparse-splitting WDM networks. Simulations are used to evaluate the effectiveness of the SLPP algorithm.

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Fabrication of a 1.3/l.55$\mu\textrm{M}$InGaAlAs/InP Dual Wavelength Demultiplexer Based on Multimode Interference(MMI) (다중모드 간섭효과를 이용한 1.3/1.55$\mu\textrm{M}$ InGaAlAs/InP 파장분배기의 제작)

  • Moon, Jeong-Yi;Yu, Jae-Su;Dong, Song-Jin;Kim, Jong-Min;Lee, Yong-Tik
    • Proceedings of the Optical Society of Korea Conference
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    • 2001.02a
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    • pp.34-35
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    • 2001
  • The wavelength demultiplexer is an essential component in optical transmission systems using wavelength-division multiplexing(WDM), which can increase the number of channels and information capacity of optical fibers. For optical telecommunication, much attention has been given to demultiplexing two wavelengths in the 1.3${\mu}{\textrm}{m}$ of low dispersion band and 1.55${\mu}{\textrm}{m}$ of low loss window. Various integrated-optical devices have been proposed to perform this function, including conventional directional couplers, asymmetric Y-branching devices, asymmetric Mach-Zehnder interferometers and two-mode interference devices. (omitted)

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A New Model of a Routing and Wavelength Assignment Problem on WDM Ring Networks (WDM 환형 망에서 경의 실정 및 파장 할당 문제의 새로운 모형)

  • Gang Dong Han;Gang Jang Ha;Park Seong Su
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2002.05a
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    • pp.397-401
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    • 2002
  • We consider a routing and wavelength assignment (RWA) problem on wavelength division multiplexing (WDM) ring networks, which is to maximize the established connections between nodes, given a set of usable wavelengths. We propose two new mathematical formulations of it and efficient algorithms based on branch-and-price method. Computational experiments on random instances show that cue of the proposed formulations yields optimal solutions in much shorter time on the average than the previous formulation due to Lee (1998).

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Wavelength Assignment Optimization in SDH over WDM Rings

  • Chung, Jibok;Lee, Heesang;Han, ChiMoon
    • Management Science and Financial Engineering
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    • v.9 no.1
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    • pp.11-27
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    • 2003
  • In this study, we propose a mathematical model based on the graph theory for the wavelength assignment problem arising in the design of SDH (Synchronous Digital Hierarchy) over WDM (Wavelength Division Multiplexing) ring networks. We propose a branch- and -price algorithm to solve the suggested models effectively within reasonable time in realistic SDH over WDM ring networks. By exploiting the structure of ring networks, we developed a polynomial time algorithm for efficient column generation and a branching rule that conserves the structure of column generation. In a computer simulation study, the suggested approach can find the optimal solutions within reasonable time and show better performance than the existing heuristics.

Wavelength and Waveband Assignment for Ring Networks Based on Parallel Multi-granularity Hierarchical OADMs

  • Qi, Yongmin;Su, Yikai;Jin, Yaohui;Hu, Weisheng;Zhu, Yi;Zhang, Yi
    • ETRI Journal
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    • v.28 no.5
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    • pp.631-637
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    • 2006
  • In this paper we study the optimization issues of ring networks employing novel parallel multi-granularity hierarchical optical add-drop multiplexers (OADMs). In particular, we attempt to minimize the number of control elements for the off-line case. We present an integer linear programming formulation to obtain the lower bound in optimization, and propose an efficient heuristic algorithm called global bandwidth resource assignment that is suitable for the design of large-scale OADM networks.

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