教程分析教案1

1、Optical Interconnect Testing100GBASE-LR4Accurate 100 GbE-LR4 Receiver Characterization DPT R&DAgilent ConfidentialMar, 1st, 2012August 13, 2022Confidentiality Label1Page 2Glossary:OMA: Optical Modulation Amplitude, measured in mW (“average signal amplitude“)ER: Extinction Ratio, high-level to low le

2、vel, measured in dB or % VECP: Vertical Eye Closure Penalty, 10 x log OMA/Ao, measured in dB (“innermost eye opening with ISI“)UI: Unit Interval (one bit period)FC: Fibre Channel LR, SR, ER, LRM: Flavors of 10 Gb Ethernet standard for Short Reach (300 m; 850 nm MM), Long Reach (10 km; 1310 nm SM), E

3、xtended Reach (40km; 1550 nm SM), Long Reach Multimode (1310 nm MM)What is optical stress?AoOMAJitterAn optical stressed signal has to be appliedwhile BER has to be below a certain levelVECP = 10 Log (OMA / Ao)Stressed receiver sensitivity conformance test:- Stress conditioning 100Gbase -LR4, -ER4Pa

4、ttern Generator:Generates the test patternFrequency synthesizer:Creates sinusoidally jittered clock, periodic jitter (PJ)Sinusoidal Amplitude Interferer 1:Causes sinusoidal jitter (SJ) in conjunction with limiterGaussian Noise Generator:Causes random jitter (RJ) in conjunction with limiterLimiter:Re

5、stores signal edges (fast rise and fall times).Sinusoidal Amplitude Interferer 2:Causes additional vertical eye-closure (VECP)and sinusoidial jitter (SJ)Low-pass filter:Creates ISI-induced vertical eye closure (VECP)N4903B JBERT +N4876A 2:1 Muxrealized by:Stressed receiver sensitivity conformance te

6、st:- WDM conformance testing 100Gbase -LR4, -ER4Tunable E/O converter for lane under test:Modulated with stressed test signal.OMA set to stressed receiver sensitivity spec“.1) Wavelength (l) tuned to corresponding worst-case sensitivity of RXuT2) Or fixed wavelength (l) in specified range of RXuTMod

7、ulated test sources for other lanes:Modulated simultanesly with valid standard pattern.1) OMA set to highest difference in receive power spec“. Wavelength (l) tuned to corresponding worst-case crosstalk to lane under test.2) OMA set to highest difference in receive power spec“ plus increment of loss

8、 variation of lane under test, plus increment of isolation variation to lane under test. Fixed wavelength (l) in specified range of RXuT81600B-132 O-band TLS +81490-E05 E/O converter +81576A Opt. Attenuatorrealized by:100Gbase-LR4 TRX +N7764A 4ch Opt. Att.realized by:Stressed receiver sensitivity co

9、nformance test:- Test signal calibration and verificationReference receiver:Optical to electrical converter with BT4 response and reference frequency ft of: ft = 19.4 GHz for 100Gbase-LR4, -ER4Oscilloscope:Use clean, un-jittered clock to verify stressed signal.86100D DCA +86105D-SIRC O/E module +861

10、07A Prec.Timebaserealized by:Agilents Stressed Receiver Test SolutionsAugust 13, 20226Key capabilities: Repeatable optical stressed pattern generation for stressed receiver sensitivity tests up to 28.4 Gb/s Built-in jitter and interference sources to achieve accurate and reproducable vertical and ho

11、rizontal eye closure: Adjustable ER, OMA, VECP and Jitter Flexibility to test optical and electrial interfaces Most precise eye and waveform analysis Automated jitter tolerance testsDemo Setup at OFC 2012August 13, 20227 Stressed Rx Sensitivity test setup according to IEEE802.3ba 100Gbase-LR4 11667C

12、Signal Uniformity of Unstressed SignalAugust 13, 20228Lane 0: 1295nmLane 1: 1300nmLane 2: 1305nmLane 3: 1310nm VECP, ER, Jitter and Mask Margin constant over all lanes PRBS 7 , PG = 600 mV, w/o SI injection adder!Adjustable Eye Closure by accurate SI InjectionAugust 13, 20229SI = 0mV Fine adjustable

13、 vertical (VECP) and horizontal (Jitter) eye closure by accurate and reproducible injection of Sinusoidal InterferenceSI = 100mVSI = 200mVSI = 250mVPRBS 7 , PG = 1400 mV, Lane 0 =1295 nmSI = 150mVSI = 300mVPattern Dependency of Unstressed SignalAugust 13, 202210PRBS 7 VECP, ER and Jitter mostly inde

14、pendent from pattern length Mask Margin slightly decreases with pattern lengthPRBS 10PRBS 11PRBS 15SI = 0mV, PG = 1400mV, Lane 0 =1295nmPattern Dependency of SI Stressed SignalAugust 13, 2022Confidentiality Label11PRBS 7 VECP, ER and Jitter nearly independent from pattern length Mask Margin slightly

15、 decreasing with pattern lengthPRBS 10PRBS 11PRBS 15SI = 200mV, PG = 1400mV, Lane 0 =1295nmStressed Receiver Sensitivity test results: - Dependency of Pattern LengthAugust 13, 202212Unstressed SRS source Penalty of 1 dB at BER 1e-10 due to higher ISI-jitter. Penalty of 2 dB at BER 1e-10 due to highe

16、r VECP and low propability effects SRS source shows pattern length dependent BER penalties, but No error floor, SRS source still within RS and SRS Spec with enough margin.RS = Receiver SensitivitySRS = Stressed Receiver SensitivityAppendixOverview 40/100G Ethernet standards100Gbase-LR4, -ER4: Basic

17、definitions100Gbase-LR4 Transceiver:Total capacity of 100Gb/s by wavelength multiplexing of 4x CWDM lanes 25.78 Gb/s on 1 SMF fiber transmisssion lineTXRX100Gbase-LR4, -ER4: CAUIPage 16The 100Gb Attachment Unit Interface (CAUI) connectingto the Physical Coding Sublayer (PCS) provides 10 x 10.3125 Gb

18、/s TX host lanes and 10 x 10.3125 Gb/s RX host lanes, each as differential line pair, summing up in total of 40 electrical input or output lines.In most CFP modules there are implemented in so-called“Gearbox/CDR”-chips 20 virtual 5Gb/s lanes for each direction. Each 10G host lane is deMuxed in 2x virtual 5G lanes.5x virtual 5G lanes are then Muxed to 1x 25G network lane.The CFP module may support optionally loopback functionality.There are 2 loopback orientations:“Host Loopback” loops the M= 10 host lanes.“Network Loopback” loops the N= 4 network l