Communication optical cable

Background

CommunicationOpticalFiberCable.Thecommunicationopticalcableiscomposedofacablecoreandanoutersheathcomposedofseveral(core)opticalfibers(generallyfromafewcorestoseveralthousandcores).Comparedwiththetraditionalsymmetricalcoppercircuitandcoaxialcoppercircuit,opticalfiberhasmuchlargertransmissioncapacity;lessattenuation;longtransmissiondistance;smallsize;lightweight;noelectromagneticinterference;lowcost,whichisthemostpromisingcommunicationatpresentTransmissionmedia.Itisbeingwidelyusedforsignaltransmissioninvarioussectorssuchastelecommunications,electricpower,andbroadcasting,andwillgraduallybecomethemainbodyofthefuturecommunicationnetwork.Themaindifferencebetweentheopticalcableandthecableinstructureisthattheopticalcablemusthaveastrengtheningmembertowithstandtheexternalmechanicalload,soastoprotecttheopticalfiberfromvariousexternalmechanicalforces.

Definition

Communicationopticalcable:literallytranslatedintoChineseiscommunicationopticalfibercable.Formaldefinition:Acertainnumberofopticalfibersformacablecoreinacertainway,theouterlayeriscoveredwithasheath,andsomearealsocoveredwithanoutersheath,whichisacommunicationlineusedtorealizethetransmissionofopticalsignals.

Chinesename:CommunicationOpticalFiberCable

Foreignname:CommunicationOpticalFiberCable

Alternativename:CommunicationOpticalFiberCable

ApplicationSubject:InformationCommunication

Features:opticalfiber,cablecore,sheath,opticalsignal

BriefHistory

Thetheoryofopticalfiberwasputforwardin1966byDr.KaoKun,aChineseBritishcitizen.ItcanbeseenthattheChinesearealsoveryintelligentandinnovative.GaoKunpointedout:Afterimprovingthemanufacturingprocess,itispossibletomakelow-lossopticalfiberssuitableforcommunication.Thispredictionwasconfirmedin1970byalow-losssilicaopticalfibermanufacturedbyCorningGlass.Thecompany'sopticalfiberlossindexis20dB/km.

In1976,theBellInstituteoftheUnitedStatesbuiltthefirstopticalfibercommunicationexperimentalsysteminAtlanta,usinganopticalcablecontaining144opticalfibersmanufacturedbyWesternElectric.

In1980,commercialopticalcablesmadeofmultimodeopticalfibersbegantobeusedoninterofficetrunklinesandafewlong-distancelinesinthecity.

In1983,commercialopticalcablesmadeofsingle-modeopticalfibersbegantobeusedinlong-distancelines.

In1988,thesubmarineopticalcableacrosstheAtlanticwassuccessfullylaid,connectingtheUnitedStates,BritainandFrance.

In1978,mycountrydevelopeditsowncommunicationopticalcable.In1984,single-modeopticalfiberswereused,andcommunicationopticalcablesweregraduallyappliedtolong-distancelines.

Structure

Cablecore

Cablecore:itislocatedinthecenterofthefiberopticcable,itisthefiberopticcableThemainbody;itsfunctionistoproperlyarrangetheopticalfibersothattheopticalfibercanstillmaintainexcellenttransmissionperformanceunderacertainexternalforce.Commonlyusedcablecorestructuresareroughlydividedintothefollowingfourtypes:

1)Strandedlayertype,whichisdividedintotwotypes:loosesleeveandtightsleeve.Figure1showsthestructureofthestrandedopticalcable.

Figure1Strandedopticalcablestructurediagram

2)Skeletontype,alsocalledtroughtype;

3)Ribbontype

4)Centralbeamtubetype,usuallyreferredtoasbeamtubetypeforshort.

So,whatisthestructuraldifferencebetweenopticalcablesandcables?Unlikecables,theconductivemetalitselfhasacertainstrength,andtheopticalcablemustbeequippedwithstrengtheningmemberstowithstandthemechanicaltensileload.Therearetwowaystoplacestrengtheningmembersforopticalcables:

1)Thecentralstrengtheningcoreisplacedinthemiddleofthecablecore,whichiscommonlyusedinstrandedandskeletonized.AsshowninFIG.ThisstrengtheningmethodismostlyadoptedbyEuropeandJapan.

2)Thewaythereinforcingmemberisplacedontheoutercircumferenceoftheprotectivelayer.ThismethodismostlyusedintheUnitedStates.

Sheath

Refertothefigureabove.Thesheathislocatedontheperipheryofthecablecoreandconsistsofaninnersheathandanoutersheath.

1)Sheath

Thesheathcommonlyusedforopticalcablesisasemi-sealedadhesivesheath.Itiscomposedofaluminumtape(PAP)orsteeltape(PSP)coatedwithplasticonbothsidesandbondedlongitudinallyontheoutsideofthecablecore.Inadditiontoprovidingmechanicalprotectionforthecablecore,thesheathmainlypreventsmoistureorwaterfromenteringthecablecore.ThePAPsheathedfiberopticcablecanbedirectlylaidinthepipelineorinstalledoverhead.ThePSPsheathedopticalcablecanbeusedfordirectburiedlaying.Ofcourse,therearebetterfullysealedmetalsheaths,buttheproductioncostishigher.

2)Outersheath

Theoutersheath(outersheath)providesfurtherprotectionforthecablesheath.It'slikeputting"armor"ontheopticalcable,wecallitarmor.Usually,itisnecessarytoarmortheopticalcableintheoccasionsofdirectburial,climbing,underwater,anti-ratbite,etc.Thetypesofarmorincludeplastic-coatedsteeltape,stainlesssteeltape,single-layersteelwire,double-layersteelwire,etc.,andnylonarmorissometimesused.Itisalsonecessarytoaddanouterlayeroutsidethearmorlayertoavoidcorrosionofthemetalarmor.

Asshowninthefigureabove,inordertopreventmoisturefromspreadingaroundonceitentersthefiberopticcable,mostofthefiberopticcablesarefilledwithcompound(grease)inthecablecore.Thiskindoffiberopticcableiscalledanoil-filledfiberopticcable.Ithastheadvantagesoflowinvestmentandlowmaintenanceworkload.

Ofcourse,therearealsogas-filledopticalcables,usingthegas-filledmaintenancemethodweintroducedearlier,sothatreal-timemonitoringcanbeachieved,andithastheadvantageoftimelytroubleshooting.Thedisadvantageisthehighercost.

Classification

Dividedbystructure

Dividedinto:1)Strandedlayertype;2)Skeletontype;3)Belttype;4)Bundletype.

Accordingtotheinstallationmethod

Dividedinto:1)overheadopticalcable;2)directlyburiedopticalcable;3)pipelineopticalcable;4)underwateropticalcable;5)localopticalcable.

Dividedbyfibertype

Dividedinto:1)Tight-bufferedfiberopticcable;2)Loose-bufferedfiberopticcable;3)Single-modefiberopticcable;4)Multi-modefiberopticcable;5)SaladshiftOpticalcable

Dividedbyfiller

Dividedinto:1)Oil-filledopticalcable;2)Inflatableopticalcable.

Trend

Comparedwithcommunicationcables,communicationopticalcableshaveaseriesofadvantages,suchaslongerrelaydistance,smallsize,lightweight,andnoelectromagneticinterference.Thereisatendencytograduallyreplacecommunicationcables.

Modelestablishmentmethod

ClassI

GYcommunicationroom(field)opticalcable,GMcommunicationmobileopticalcable,GJcommunicationroom(office)Internalopticalcable,GScommunicationequipmentinternalopticalcable,GHcommunicationsubmarineopticalcable,GTcommunicationspecialopticalcable.

ⅡReinforcement

Metalwithoutmetalreinforcement

FNon-metalreinforcement

GMetalheavyreinforcement

ⅢOpticalfibercablestructurecharacteristics

SOpticalfiberloosetubecoatingstructure

JOpticalfibertightsleevecoatingstructure

DOpticalfiberribbonstructure

Strandedstructurewithoutlayer

Gskeletongroovestructure

Xcablecentraltube(coated)structure

Tfilledstructure

BFlatstructure

Zflameretardant

Cself-supportingstructure

Ⅳsheath

Ypolyethylene

VPolyvinylchloride

FFluoroplastic

UPolyurethane

EPolyesterelastomer

AAluminumtape-polyethyleneadhesiveBondinglayer

Ssteelstrip-polyethylenebondingsheath

Wsteelstripwithsteelwire-polyethylenebondingsheath

LAluminum

Gsteel

Qlead

ⅤOutersheath

(1)Armorlayer

0NoneArmored

2doublesteelbelt

3thinroundsteelwire

4thickroundsteelwire

5corrugatedsteelbelt

6Doubleroundsteelwire

(2)Outerlayerorjacket

1Fiberoutersheath

2Polyvinylchloridesheath

3Polyethylenesheath

4Polyethylenesheathplusnylonsheath

5Polyethylenetube

ⅥFibercorenumberdirectlyWrittenbyArabicnumerals

ⅦFibercategoryAMulti-modefiberBSingle-modefiber

Causeoffailure

I.Impactoflightning

Thearmoringcomponentsoftheopticalcableareallmetalconductors.Ifthepowerlineproducesashortcircuitorlightningstrikesthemetalparts,astrongcurrentwillbegeneratedtodamagetheopticalcablelineequipment,anditmayevenoccurinseverecases.Casualtiesofpersonnel.

Second,theinsulationoftheopticalcablelineisnotgood

Ifthecommunicationopticalcablelineisnotwellinsulated,thentheconnectorboxwillbeexposedtowaterordampInthiscase,theoperatingstrengthoftheopticalcablewillbegreatlyreducedduetostresscorrosionandstaticfatigue.Inseverecases,theopticalcablemaybreak.

3.Theinfluenceofexternalforces

Inmanycases,linefaultsarecausedbyexternalforces.Sincemanycommunicationopticalcablelinesarelaidinthefield,andthegeneralburyingstandardsaredeepbelowtheground,itisimpossibletoeffectivelyavoidthedamageofmanyexternalfactorstotheopticalcablelines.

Four.Faultsatthelinejoints

Thefaultsaremostlikelytooccuratthelinejoints,becausetheopticalfibersatthejointsaffecttheoriginalopticalcablestructureTheprotectivepowerisnolongeravailableortheprotectivepowerhasbeensignificantlyweakened,sothedailyoperationandprotectionworkcanonlyrelyontheconnectorbox,whichleadstoagreatlyincreasedprobabilityoffailure.