A NEW APPROACH TOA NEW APPROACH TO REMOTE REMOTE FIBER TESTINGFIBER TESTING IN OPTICAL IN OPTICAL

NETWORKSNETWORKSKreKreššoo ŽŽmakmak

University of Zagreb, Faculty of Electrical Engineering and CompUniversity of Zagreb, Faculty of Electrical Engineering and Computing uting

IntroductionIntroduction New New approachapproach to RFTS to RFTS

SystemSystem architecturearchitecture ErrorError correctioncorrection methodmethod

MeasurementMeasurement resultsresults SummarySummary

OutlineOutline

IntroductionIntroduction

OpticalOptical communicationcommunication systemssystems (OCS) (OCS) formform thethebasisbasis ofof allall telecommunicationtelecommunication networksnetworks

TheThe developmentdevelopment ofof OCS OCS waswas followedfollowed byby thethedevelopmentdevelopment ofof RemoteRemote FiberFiber TestingTesting SystemsSystems(RFTS)(RFTS)

TheThe priceprice ofof thethe currentcurrent RFTS RFTS exceedsexceeds thethe priceprice ofoflocallocal andand accessaccess networksnetworks

ErrorError--detectiondetection andand errorerror--correctioncorrection raiseraise to to fewfewdaysdays, , eveneven weeksweeks

New RFTS New RFTS ►► a a lowlow--costcost andand reliablereliable tooltool forfor errorerrordetectiondetection inin locallocal andand accessaccess networksnetworks

MeasurementMeasurement systemsystem TheThe newnew systemsystem representsrepresents thethe fundamentalfundamental ((simplestsimplest) ) formform

ofof thethe future test future test systemsystem MainMain purposepurpose

ErrorError detectiondetection inin OCS (OCS (mechanicalmechanical faultsfaults oror qualityquality losseslossesinin opticaloptical fibersfibers oror connectorsconnectors))

MainMain ideaidea ModificationModification ofof thethe currentcurrent RFTS RFTS inin orderorder to to lowerlower itit’’s s priceprice

New RFTSNew RFTS OTDR OTDR asas mainmain

measurementmeasurement unitunit OpticalOptical powerpower splittersplitter SoftwareSoftware controlcontrol

CurrentCurrent RFTSRFTS OTDR OTDR asas mainmain

measurementmeasurement unitunit OpticalOptical SwitchSwitch SoftwareSoftware controlcontrol

MeasurementMeasurement unitunit OTDR OTDR OpticalOptical powerpower splittersplitter

ControlControl unitunit PCPC SoftwareSoftware PrePre--measurementmeasurement

managementmanagement PostPost--measurementmeasurement

managementmanagement SerialSerial interfaceinterface connectionconnection

(RS232)(RS232)

MeasurementMeasurement systemsystem architecturearchitecture

MeasurementMeasurement processprocess

1.1. MeasurementMeasurement setupsetup

2.2. OTDR OTDR launcheslaunches thethe pulsepulse

3.3. InputInput powerpower isis divideddivided

4.4. OutputOutput pulsespulses traveltravel throughthroughthethe fiberfiber

5.5. AllAll scatteredscattered andand reflectedreflectedsignalssignals formform a a complexcomplexmeasurementmeasurement tracetrace

6.6. OTDR OTDR tracetrace savedsaved inin thethecomputercomputer memorymemory

7.7. MeasurementMeasurement analysisanalysis

ErrorError detectiondetection –– reference reference measurementmeasurement

BasedBased on on comparisoncomparison ofof reference reference andand test test measurementsmeasurements Reference Reference measurementsmeasurements performedperformed afterafter thethe installationinstallation ofof

thethe OCSOCS MeasurementMeasurement pointspoints defineddefined at at characteristiccharacteristic eventsevents on on thethe

OTDR OTDR tracetrace ((splicessplices, , fiberfiber endend, , connectorconnector reflectionsreflections))

ErrorError detectiondetection –– measurementmeasurement comparisoncomparison

ErrorError : : TheThe differencedifference ofof thethe powerpower levellevel betweenbetween thethe test test andand

reference reference measurementsmeasurements, at , at thethe measurementmeasurement pointspoints, , exceedsexceeds a a predefinedpredefined tresholdtreshold levellevel

Test Test measurementsmeasurements automaticalyautomaticaly performedperformed inin time time intervalsintervals whichwhich varyvary fromfrom 1 1 minmin to 1 to 1 hourhour

RFTS RFTS managementmanagement softwaresoftware

SpeciallySpecially developeddeveloped forfor thethe newnew systemsystem

The program was developed using the The program was developed using the MicrosoftMicrosoftTMTM Visual BasicVisual BasicTMTM software packagesoftware package

ThreeThree modulesmodules MainMain module module

ComparisonComparison modulemodule

AutomaticAutomatic test moduletest module

TheThe program program partitionpartition enablesenables a a simplesimple andand fastfastsoftwaresoftware managementmanagement

MainMain modulemodule

FunctionsFunctions :: MeasurementMeasurement setupsetup (OTDR (OTDR setupsetup))

Reference Reference measurementmeasurement controlcontrol MeasurementMeasurement pointspoints definitiondefinition

UserUser--friendlyfriendly interfaceinterface –– easyeasy andand efficientefficientmeasurementmeasurement pointspoints definitiondefinition

5000,500005000,500001 to 99991 to 999910,20,50,10010,20,50,1001310,15501310,1550

SpatialSpatial resolutionresolution((numbernumber ofof samplessamples))

AveragingAveragingtime (s)time (s)

OutputOutput pulse pulse widthwidth((nsns))

WavelenghtWavelenght(nm)(nm)

MainMain module module useruser interfaceinterface

ComparisonComparison modulemodule FunctionsFunctions ::

Test Test measurementmeasurement controlcontrol Test Test measurementmeasurement resultresult analysisanalysis ErrorError detectiondetection

AutomaticAutomatic errorerror detectiondetection basedbased on on comparisoncomparison ofof test test andand reference reference measurementmeasurement resultsresults

GraphicalGraphical UserUser interfaceinterface :: reference reference waveformwaveform windowwindow test test waveformwaveform windowwindow differencedifference waveformwaveform windowwindow bothboth waveformwaveform windowwindow

ComparisonComparison module module useruser interfaceinterface

AutomaticAutomatic test moduletest module

ModifiedModified versionversion ofof thethe comparisoncomparison modulemodule FullyFully automatizedautomatized test test measurementsmeasurements andand errorerror

detectiondetection Module Module parametersparameters ::

MeasurementMeasurement repetitionrepetition time interval time interval ErrorError tresholdtreshold levellevel

MeasurementMeasurement resultsresults

PowerPower splittersplitter 90/10 90/10 simulatessimulates thethe casecase wherewhere thethe powerpowerisis equallyequally divideddivided to 10 to 10 fibersfibers

AsAs ““errorerror casecase”” wewe disconnecteddisconnected one one fiberfiber

1000/3000 1000/3000 3000/3000 3000/3000

(5m (5m differencedifference ))

1310131015501550

1010100100

50/50 50/50 75/2575/2590/1090/10

Test Test fibersfibers (m)(m)WavelengthWavelength (nm)(nm)Pulse Pulse widthwidth((nsns))PowerPower splittersplitter

WavelenghtWavelenght, pulse , pulse widthwidth andand powerpower ratioratio dominantlydominantlyinfluence influence thethe measurementmeasurement resultsresults

MeasurementMeasurement parametersparameters valuesvalues ::

NoNoYesYesNoNoYesYesNoNoYesYesNoNoYesYesNoNoYesYesNoNoYesYesErrorErrordetectiondetection

100100 100100 100100 100100 100100 100100101010101010101010101010Pulse Pulse widthwidth((nsns))

1550155015501550

3000/30003000/3000Test Test fiberfiber (m)(m)

15501550131013101310131013101310WavelengthWavelength(nm)(nm)

90/1090/1072/2572/2550/5050/50PowerPower splittersplitter

ErrorError detectiondetection forfor fibersfibers withwith similarsimilar lenghtlenght

YesYesYesYesYesYesYesYesYesYesYesYesYesYesYesYesYesYesYesYesYesYesYesYesErrorErrordetectiondetection

100100 100100 100100 100100 100100 100100101010101010101010101010Pulse Pulse widthwidth((nsns))

1550155015501550

1000/30001000/3000Test Test fiberfiber(m)(m)

15501550131013101310131013101310WavelengthWavelength(nm)(nm)

90/1090/1072/2572/2550/5050/50PowerPowersplittersplitter

ErrorError detectiondetection forfor fibersfibers withwith differentdifferent lenghtlenght

TheThe newnew RFTS RFTS ►► a a modificationmodification ofof thethe currentcurrentRFTSRFTS

ParralelParralel fiberfiber testingtesting usingusing thethe powerpower splittersplitter TestsTests confirmedconfirmed thethe systemsystem efficiencyefficiency

Future :Future : ActiveActive opticaloptical networknetwork ErrorError locationlocation methodmethod

SummarySummary