pon fttx advanced testing procedures and equipment - · pdf file [email protected] 1 pon_fttx...
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Typical FTTx Infrastructure
Commercial NetworkOptical Access NetworkBackbone & Bearer Network
1xN SplitterONU
ONU
ONU
ONU
OpticalVideoTransmitter
EDFA
WDMCoupler
OLT
COCATV
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Downstream1490 nm
Upstream1310 nm
1490nm/1310nm/1550nm
Voice & Data Voice/Data/Video
Splitter(1x32)
WDMCoupler
Video1550 nm
OLT
EDFA
ONU
FTTx Services
1310 nm 1490 nmDownstreamUpstream
1550 nm
Analog TV & Digital TVHD/VOD
110 MHz 860 MHz5-65 MHz
Bandwidth & Service
VideoVoice & Data@ 622 Mbps
Voice & Data@ 155 to 622 Mbps
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Imperative FTTx
Replacement ofcopper cableswith optical cables
Full-servicebroadbandrequirement
SupportFull-serviceAccess
IndustryRestructuring
FTTxPON
Customer RequirementCompetitionTechnical TrendNetwork and Service TransitionEnterprise Cost
VoiceDataVideo
High band-width consumptionservices emerges: P2P, on-line video,IPTV
More high band-width requirementfrom customer
Telecom resource allocation isoptimized. Aggravated Competition.
Single service competition extends tofull-service competition
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FTTx Trend
Integrated Home &Commercial NetworkHigh-speed Optical Access Network
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FTTxNetwork Testing
Installation Service DeploymentMaintenance &Troubleshooting
The Challenge for FTTx Testing
New wavelength: 1490nm
Water peak cause additional loss
Short-distance fiber connection
application
Require high-accuracy OTDR
Vast connector application in the
network
The cleanness and reliability of optical
connectors
Bi-directional loss test
Ensure bi-directional transmission
quality
Macro bend inspection
Vast connector application in networkThe cleanness and reliability of optical
connectorsWavelength multiplexing/Bi-direction/High
power/Burst modeFilter/Burst mode detecting/Dual port Power
MeterSplitters used in the networkHigh accuracy and high dynamic OTDRBroadcastingOTDR: In-service test/pass thru splitter
Vast connector application in networkThe cleanness and reliability of optical
connectorsWavelength multiplexing/Bi-direction/High
power/Burst modeFilter/Burst mode detecting/Dual port
Power MeterSplitters used in the networkHigh accuracy and high dynamic OTDRBroadcasting TypeOTDR: In-service test/pass thru splitterVisible fault locator
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FTTx Installation Stage
New wavelength: 1490nm
Water peak cause additional loss
Short-distance fiber connection application
Require high-accuracy OTDR
Vast connector application in network
The cleanliness and reliability of optical connectors
Bi-directional loss test
Ensure bi-directional signal transmission quality
Macro bend inspection
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Segment Test on Entire Fiber Linkwith OTDR
OLT Splitter
ONU
ONU
New wavelength: 1490nm
Potential problem: Water peak causes
additional lossWater peak fiber All wave fiber
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Triple-wavelength test:
1310/1490/1550nm in PON
Verify if network quality meets the requirement of FTTx servicesignal transmission at installation stage
Short distance fiber application (small dead zone):
High accuracy for testing events in short distance
Additional function: SLS+OPM+VFL
Optional built-in functions make the verification work duringnetwork construction easier
Solution:PON OTDR for Installation Stage
1310nm
1490nm1550nmPALM-OTDR-S20C/P
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Triple-wavelength on PON / Bi-directional Transmission
Need for Bi-directional Optical loss test
Segment Fiber(Cable) / Test of Splitter Loss
Need for testing each fiber(cable) segment and splitter loss fromboth directions
Bi-directional Optical Loss Test
OLT Splitter
ONU
ONU
Transmission Fiber
1490nm Downstream Voice/Data
1550nm Downstream Video
1310nm Upstream Voice/Data
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Solutions:Three available
OLT Splitter
ONU
ONU
1. Test entire fiber link loss and ORL using OLT-50P on both directions2. Or test fiber link loss with HH-OTDR-S20C/P-PS (OTDR+SLS+OPM)3. Or test fiber link loss with PPM-30-PS (PPM+SLS+OPM)
OLT-50PPPM-30-PSPPM-30-PSPALM-OTDR-
S20C/P-PSOLT-50P PALM-OTDR-
S20C/P-PS
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FTTx Deployment Stage
Vast connector application in networkThe cleanliness and reliability of optical connectorsWavelength multiplexing/Bi-direction/High power/Burst
modeBuilt-in filter/Burst mode detecting/Dual port Power MeterSplitters used in the networkHigh accuracy and high dynamic OTDRBroadcasting signals from OLTOTDR: In-service test/pass through splitter
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Wavelength multiplexing
Bi-directional
PON Power TestUsing a PON Power Meter
High power
Burst mode
1490nm Downstream voice/data
1550nm Downstream video
1310nm Upstream voice/data
WDM
1550nm Downstream video EDFA Up to +17dBm
ONU1#
ONU2#
ONU3#
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Test 1: Downstream signals at two wavelengths
2 signals of different wavelengths and power1550nm CATV signal of 17dBm
1490nm data signal of 4dBm
Value displayed on normal OPM: about 17.1dBm
Separate power of 1490nm & 1550nm signals ?
Optical Power Test-1
Solution:
Power meter with built-in wave filter
Good channel isolation
Coupler
WDM
1550nm
1490nm 1310nm
1310nm
1490nm 1550nm
1490nmDetector
1550nmDetector
1310nmDetector
1490/1550nm
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Solution:Power Meter has dual optical ports (Pass through)
Test 2: How to measure upstream signal at 1310nm on the same fiber ?
- ONU transmits 1310nm upstream signal only when OLTactivation signal received (G.983)
- ONU stops transmitting when fiber is disconnected
- Ordinary power meter won't work
PPM-30PON Power Meter
Optical Power Test-2
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Test 3: Test upstream sparse signalONU transmits 1310nm upstream signal only in certain timeslot
OLT controls time slotONU communicates with OLT periodically (100ms, due tosystem difference; Order of magnitude on EPON: ns
Solution:Power Meter supports burst modePower Meter complies with EPON\GPON testing requirementAutomatically identify PON standard and switch to corresponding test
mode
OLT Splitter
ONU1
ONUn
ONU21 2 n
1310nm 12
n
Optical Power Test-3
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Test Point 1: At Splitter
Power of downstream 1550nm video signal
Power of downstream 1490nm data signal
Separate test at each port
Service Activation Test-Test Point 1
ONUOLT DTSP
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Test Point 2: At Drop Terminal
Power of downstream 1550nm video signal
Power of downstream 1490nm data signal
Signal from CO through splitter
Separate test at each port
ONUOLT DTSP
Service Activation Test-Test Point 2
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Test Point 3: At ONU (Pass-through Test)
Power of downstream data & video signals
Power of upstream data signal
Signal power after all kinds of PON components
PPM-30 features pass-through function, ideal for serivce
activation test
OLT DT ONUSP
Service Activation Test-Test Point 3
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PPM-30 has 60 definable threshold sets
Each set consists of 3 wavelengths with their own pass, warning
and fail thresholds:
1310, 1490, 1550nm
Threshold sets for different test points:
Drop Terminal, ONU, FDH etc.
At ONU for example:
Fail
Pass
Warning
Fail
6 dBm(pass)2 dBm(warning)1 dBm(fail)
1310 nm
Fail
Pass
Warning
Fail
-4 dBm(pass)-22 dBm(warning)-25 dBm(fail)
1490 nm
Fail
Pass
Warning
Fail
6.9 dBm(pass)-10.6 dBm(warning)-13.6 dBm(fail)
1550 nm
Service Activation Test-Pass/Fail Assessment
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OTDR issues in PONs
High insertion loss may cause test error using traditional
OTDR
Broadcasting
Splitter type Theoretical loss
1:2 3dB1:8 9dB1:16 12dB1:32 15dB1:64 18dB
SplitterOLT
Splitter is the main power consumptionin PON
Broadcasting from OLT though splitter
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Solution: OTDR Application at PONDeployment StageDynamic Range:
- To test fiber from end to end, the dynamic range of OTDR should be high
- For Class B equipment, the minimum dynamic range should be above 33
dB.
Short dead zone:
High accuracy for testing events in short distance
Triple-wavelength test:To test triple-wavelengths in PON:1310/1550/1625nm
Wave filter / Test trhough splitter:1625nm wavelength with filter /Test through splitter
Splitter and fiber-end identifiable
Additional function: SLS+OPM+VFL
Optional built-in functions make the verification work during network
construction easier
PALM-OTDR-S20C/X
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Trace of palmOTDR testing through splitter (Splitter introduces high insertion loss,
12dB typically for 1*16 splitter): splitter, events after splitter including fiber-end are
identifiable
The Challenge to OTDR Testing -Testing Through Splitter
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FTTx Maintenance Stage
Vast connector application in networkThe cleanliness and reliability of optical connectorsWavelength multiplexing/Bi-direction/High power/Burst
modeWith Filter/Burst mode detecting/Dual port Power MeterSplitters applicationHigh accuracy and high dynamic OTDRBroadcastingOTDR: In-service test / Test through splitter
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First inspect the whole situation, then go for partial inspectionFirst diagnose and determine fault type: overall or partial/individual faultFor large scale breakdown, inspect CO (central office) firstFor partial/individual fault, troubleshoot at fault point
First outdoors, then indoor inspection (on end user site)To inspect outdoors e.g, splitter or other equipment on the end user site first.Troubleshoot fault at end-user site after outdoor check points inspected
Progressive inspectionProgressive inspection, Fault locating, Troubleshooting
Maintenance Suggestion
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Fault Case 1:ONU LOS Warning
Use PPM-30 to measure at different test points from ONU to OLT
PPM-30 can measure triple-wavelength signals simultaneously
OLT SP DT ONU
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Fault Case 1- Fault Analysis
Reason: The loss on splitter port is too high,which cause significant signal loss on the link
Solution:
Suggestion: Keep spare ports as backup in construction design.2. To inspect the cleanliness of fiber/connector end-face with OCI-20 opticalconnector inspector.
Clean the connector first and re-measure optical powerReplace the connector if it is damaged or cleaning fails
ONUOLT SP DT
Port with potential fault
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To locate fault at different points from ONU to OLT using PPM-30 PON powermeter
To use OTDR for fault locating if the fault is on the fiber link
ONUOLT SP DT
To test in segment from ONU or Splitter by OTDR to locate faultaccurately.With filter at 1625nm wavelengthIn-service testing
Fault Case 2:Low or lost ONU signal
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Fault Case 2- Fault Analysis
Reason: Connector or fiber is damaged
Solutions:1.To test from ONU, then locate and fix fault.
ONUOLT SP DT
Potential fault
2.To detect fault on connector with visible fault locator. To reconnect orreplace the connector if the red light glows obviously on connector end-face.
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PON Maintenance OTDR
Working wavelength: 1625nm (Single wavelength is enough for in-
service troubleshooting, cost-effective)
Built-in filter, in-service test
Test through ×64 splitter
Splitter and fiber-end identifiable
Dynamic range 35dB
Short dead zone 1.6m
Macrobend detection with visible laser source
Additional function: SLS+OPM Optional built-in functions make the
verification work during network construction easier PALM-OTDR-S16C/N
OTDR VFL
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OTDR Solution
PALM-OTDR-S16C/NSpecial for testing at PON
maintenance stage1625nm with filterDynamic range: 37dBIn-service test
×64 splitterSplitter & fiber identifiable650nm Visible Fault LocatorOptional SLS/OPM
PALM-OTDR-S20C/XSpecial for testing at PON
service deployment stage1310/1550/1625nm
(1625nm with filter)Dynamic range: 38/37/37dBIn-service test
×64 splitterSplitter & fiber identifiableOptional SLS/OPM/VFL
PALM-OTDR-S20C/PSpecial for testing at PON
installation stage1310/1490/1550nmDynamic range: 38/37/37dBVerify if network quality meets the
requirement of FTTx service signaltransmission
Optional SLS/OPM/VFL
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Loss Testers and Power Meters
OLT-50P Optical Loss TesterSLS working wavelength:
1310/1490/1550nmOPM calibrated wavelength:
850/1300/1310/1490/1550/1625nmAuto bi-directional loss testAuto wavelength
identification/SwitchORL test
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PPM-30 PON Power Meter1310/1490/1550nmsimultaneous measurementPass-through testBurst modeBuilt-in filterOptional SLS/OPM/VFL
Model Wavelength(±20nm)
DynamicRange(dB) Event DeadZone(m) Attenuation
DeadZone(m)
palmOTDR-S16C/N 1625 37 1.5 10
palmOTDR-S20C/P 1310/1490/1550 38/37/37 2.5 14
palmOTDR-S20C/X 1310/1550/1625 38/37/37 1.5 10
Connector FC/PC (Interchangeable SC, ST)
Averaging Time 15s,30s,1min,2min,3min
Distance MeasureAccuracy ±(1m + 5×10-5×distance + sampling space)
Attenuation DetectAccuracy ±0.05 dB/ dB
Data Storage 1000 records
Connectivity RS-232/USB
Power Supply NiMH Battery / AC Adapter
Battery Life 8 hours continuous operation; 20 hours standby (on one charge)
PALM-OTDR Handheld OTDR
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PPM-30 PON Power MeterModel PPM-30
Calibrated Wavelength 1310nm 1490nm 1550nmMeasurement Range (dBm) -40 ~ +10 (1) -40 ~ +12 -40 ~ +20Spectral Passband (nm) 1310±50 1490±15 1550±10Power Uncertainty (dB)Accuracy (dB) 0.01Insertion Loss (dB)Visible Fault Locator (Optional)Output Power (dBm) -3Max Measurement Range 5 KmOptical Power Meter (Optional)Calibrated Wavelength (nm) 850,1300,1310,1490,1550,1625Power Range (dBm) (2) -70 ~ +10Detector Type InGaAsAccuracy ± 5%± 0.01nW(±0.5dB@850nm)MOD Identification 270, 1K, 2K HzStabilized Laser Source (Optional)Wavelength (±20nm) 1310, 1490, 1550nmOutput Mode CW, 270Hz, 1KHz, 2KHzSpectrum Width (nm)Output Power (dBm) -7Stability ±0.05dB/15min,±0.10dB/8hr@ 1310/1550Output Power Display YesConnector FC/PC (Interchangeable SC, ST)General SpecificationsData Storage >2000 recordsData Interface USBPower Supply NiMH Battery (1600mAh, 9.6V) / AC AdapterBattery Life
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Model OLT-50PStabilized Laser SourceWavelength (±20nm) 1310/1490/1550Spectrum (nm)Emitter Type FP-LDOutput Power (dBm) >-4Stability ±0.05dB/15min;±0.10 dB/8 hours@1310/1490/1550nmOutput Mode CW, 270Hz, 1kHz, 2kHz
Optical Power MeterCalibrated Wavelength (nm) 850, 1300, 1310, 1490, 1550, 1625Power Range (dBm) -70~+10 -50~ +27UnitDetector Type InGaAsAccuracy ±5%±0.01nW (±0.5 dB@850nm) ±5%±1nW(±0.5 dB@850nm)Resolution 0.01dBAuto Wavelength Identification Yes (With ShinewayTech specified Stabilized Laser Source)MOD Tones (Hz) 270, 1K, 2K
Optical Loss TestLink Loss Range 50dB (1550nm, 200km)Link Loss Accuracy ±0.25dBLink Loss Test Time < 2second / wavelengthORL (Optional)ORL Range 0 ~ 60dBORL Accuracy ±0.75dB@(0 ~ 50dB),±1.5dB@(50 ~ 60dB)ORL Uncertainty ±0.5dB@20dB
OLT-50 Optical Loss Tester
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