光纤通信课程设计课件Class1-03.pptx

TypesTypesHot Hot SpotsSpotsFactorsFactorsLayoutLayoutHot Hot SpotsSpotsTypesTypesFactorsFactorsLayoutLayoutMaximize the Profit(利益最大化）利益最大化）IP over WDMInstead of using IP over SDH over WDM,direct IP over WDM is employedOTN(光传送网）光传送网）Optical Cross-connectionElectronic Cross-connectionG.709GMPLSUltra long haul and super bandwidth10G,25G,40GTypesTypesLayoutLayoutHot Hot SpotsSpotsFactorsFactorsClassified by Channel SpacingWide:WWDM Coarse:CWDM 20nmNarrow:NWDMDense:DWDM 100MHz,0.2-1.2nmClassified by InterfacesOpenHalf-OpenIntegratedClassified by Channel NumbersChannel SpeedLayoutLayoutTypesTypesHot Hot SpotsSpotsFactorsFactorsOSC/ESC:Optical/electrical Supervisory ChannelOTU:Optical Transport Unit(光转发单元光转发单元)AttenuationAttenuation Absorption and ScatteringAbsorption and Scattering DispersionDispersion ModalModal WaveguideWaveguide MaterialMaterial PMDPMD Signal-to-Noise ratioSignal-to-Noise ratio ASE in EDFAASE in EDFA Accumulated NoiseAccumulated Noise Nonlinear EffectsNonlinear Effects SPM,XPM,FWM,SBS,.SPM,XPM,FWM,SBS,.FactorsFactorsLayoutLayoutHot Hot SpotsSpotsTypesTypesLearning Network Design by Learning Network Design by Gaining a understanding of building blocksGaining a understanding of building blocksDesign idea-setup-performance testingDesign idea-setup-performance testingRight tool for right job:OptisystemsRight tool for right job:OptisystemsPractice:Practice:In-class design 40%In-class design 40%Homework 30%Homework 30%Final 30%Final 30%WhatWhatWhenWhenHowHowGradeGradeCoverageCoverageSimpleSimpleAdd-onAdd-onModifiedModifiedLinear DistortionAttenuation-BERDCFPMDWDM,DWDM,PONEDFA,RamanNonlinear DistortionFWM,SBSNetworkOCDMA,OFDM40G,100G,CoverageCoverageSimpleSimpleAdd-onAdd-onModifiedModified Basic P-to-PFamiliarity with OptisystemsParameter selectionHow to evaluate your resultBERSimplicityTotal cost:using BOMDesign processAnalyze your taskDefine your need:capacity,BER,cost,CoverageCoverageSimpleSimpleAdd-onAdd-onModifiedModified Definition:The number of Bit errors that occur within the space of one second.Range:10-9 to 10-12 The higher the Data Transmission rate the greater the standard.DS-1(1.544 Mbit/s)signal is considered acceptable with a BER of 10-6,OC-3(155.52 Mbit/s)signal requires a BER of no more than 10-12.CoverageCoverageSimpleSimpleAdd-onAdd-onModifiedModified Test equipment:BERT BER tester two fundamental parts:1.signal pattern generator 2.error detector Signal pattern generator Producing a known data sequence,intentionally stress some aspect,like difficult for the clock recovery system to synchronize.Most common pattern:pseudo-random binary sequence(PRBS)Error detectorcompared bit by bit between two signals.BER=number of incorrectly received bits/total number of bits transmittedCoverageCoverageSimpleSimpleAdd-onAdd-onModifiedModified Why is BER difficult to simulate or calculate?For a given design BER estimate BER dynamically calculate Q from OSNR,ROP,eye-diagramCoverageCoverageSimpleSimpleAdd-onAdd-onModifiedModified Q is a measure of the quality of any signal If the noise is known to be Gaussian,Q fully determines BER In many cases,Q(10)Q6:A rule of thumb!CoverageCoverageSimpleSimpleAdd-onAdd-onModifiedModified Optical signal to noise ratio(OSNR)Bit Error Rate The Eye diagram Q-factorCoverageCoverageSimpleSimpleAdd-onAdd-onModifiedModified OSNR is important because it suggests a degree of impairment when the optical signal is carried by an optical transmission system that includes optical amplifiers.Optical signal suffers more than only attenuation.In amplitude,spectrally,temporally signal interaction with light-matter,light-light,light-matter-light Leading to Signal disturbances such as:Power reductionDispersionPolarizationUnbalanced amplificationThus leading to random noise,which causes misalignments,jitter and other disturbances resulting in BERCoverageCoverageSimpleSimpleAdd-onAdd-onModifiedModifiedGiven the OSNR,the empirical formula to calculate BER for single fiber is Log10(BER)=10.7-1.45(OSNR)Example:Assume that OSNR=14.5 dB Then Log10(BER)=10.7-1.45(14.5)=-10.30 Therefore BER=10-10.30 BER is approx 10-10More complicated calculations may refer to CISCO webpage http:/ QdB=OSNR+10log(BWo/Bwe),1/OSNR=1/OSNR1+1/OSNR2+CoverageCoverageSimpleSimpleAdd-onAdd-onModifiedModifiedIn transmission,a quick and qualitative measure of the quality and integrity of the electronic signal(since optical has been converted to electrical)is a superpositionofbitperiodsonanoscilloscope.This superposition is known as the“eye diagram”If the signal has little noise and the amplitude is sufficient to be clearly recognized as“one”(marks)or“zero”(spaces)the superposition provides an“open eye”,otherwise eye is corrupted and“fuzzy”CoverageCoverageSimpleSimpleAdd-onAdd-onModifiedModifiedMinimum current threshold for logic 1 is set to I 1,min Maximum current threshold for logic 0 is set to I0,maxOpening of the Eye,E Eye=I 1,min-I 0,maxCoverageCoverageSimpleSimpleAdd-onAdd-onModifiedModifiedJitter:tEeye，EmaxCoverageCoverageSimpleSimpleAdd-onAdd-onModifiedModifiedCoverageCoverageSimpleSimpleAdd-onAdd-onModifiedModifiedCoverageCoverageSimpleSimpleAdd-onAdd-onModifiedModified Measure BER as a function of mean receivedopticalpower(ROP)for each ROP,decision threshold is optimized,and the BER measured Receiver sensitivity is the ROP required to achieve a specific BER(10-9,10-12)Find power penalty for with and without“optically amplified link”