Definition
Communicationline:Inwiredcommunication,thetransmissionmediumthattransmitselectromagneticwavesignalsfromoneplacetoanother.
Chinesename:Communicationline
Foreignname:
Alternativename:None
>Theearliestcommunicationlinewasanoverheadopenline.In1844,theUnitedStatesestablishedanoverheadlinebetweenWashingtonandBaltimore.Atthattime,thesignaltransmittedbytheoverheadopenwirewasnotatelephonesignal,butatelegraph.Theso-calledoverheadopenwire(seetheterm"overheadopenwire")isthebarewirethathangsonthepole.AsshowninFigure1.
Figure1Overheadopenlinethroughthewilderness
By1850,asubmarinecableacrosstheEnglishChannelwassuccessfullylaidbetweenBritainandFrance,whichwasofcoursealsousedtosendtelegrams.
Thetelephonewasnotinventeduntil1876.Everyonefindsthatopenwiresorcablesaresusceptibletoexternalinterference;crosstalkiseasytobefoundbetweenlines,andthequalityofcallsispoor.Scientistsbegantoexploretirelessly,tryingtofindagoodsolution.Forexample,usedoublewiresinsteadofsinglewires,andexploretechniquessuchasopenwirecrossoverandcablebalancetoimprovetransmissionquality.In1941,theUnitedStatesinnovativelyadoptedacoaxialcableline,and480voicechannelscouldbeopenedononeline.Later,itdevelopedto3,600,10,800,and13,200;thetechnologyofcommunicationlineshasmadeaqualitativeleap.
In1976,100yearsaftertheinventionofthetelephone,thefirstpracticalcommunicationopticalcablewassuccessfullyappliedtotheAtlantaExperimentalSystemoftheBellInstituteintheUnitedStates.In1988,thefirstsubmarineopticalcableacrosstheAtlanticwassuccessfullylaid.Didyouguysfindout?TheUnitedStateshasalwaysbeenattheforefrontoftechnologicalprogress!so.Thestatusof"BigBrother"intheAmericanworldtodayisnotobtainedoutofthinair,buthasalsoexperiencedhardwork,explorationandinnovation.
Let’stakealookatChinaagain.Theearliestcommunicationlinestartednottoolate.In1871,ChinalaidthesubmarinecablefromShanghaitoJapan,butthetechnologywasnotinthehandsoftheChinese.ThissubmarinecablewasfromDenmark.ItwasbuiltbytheGreatNorthernTelegraphCompany.Itwasnotuntil1881thatChinaestablishedthefirstlong-distanceoverheadlinebetweenShanghaiandTianjin.Itwasnotuntil1962afterthefoundingofNewChinathatthe60-channelcarrierlong-distancesymmetricalcabledesignedandmanufacturedinmycountrywasputintousebetweenBeijingandShijiazhuang.In1976,1,8004-pipecoaxialcablesdesignedandmanufacturedinmycountrysuccessfullyconnectedBeijing,ShanghaiandHangzhou.In1978,mycountrysuccessfullydevelopedamulti-modeopticalfibercommunicationcable.After1984,single-modefiberwasusedonlong-distancelines.
Classification
Accordingtotransmissionmedia
Therearedifferentclassificationsofcommunicationlines.Ifdividedaccordingtothetransmissionmedium,itcanbedividedintothefollowingfourcategories:
1)Overheadopenwire
2)Communicationcable
3)Communicationopticalcable
4)Communicationsubmarinecable
Distinguishbyimportance
Ifaccordingtotheimportanceofcommunicationlines,communicationlinescanbedividedintofirst-levellines,second-levellines,andthird-levellines.Levellines,etc.
1)First-levelroutes:refertolong-distanceroutesandinternationalroutesdesignatedbytheMinistryofIndustryandInformationTechnologybetweenthecapitalandthecapitalsofprovinces,municipalities,andautonomousregions,betweenprovincialcapitals,municipalities,andautonomousregions.
2)Secondarylines:refertolong-distancelinesdesignatedbytheprovincial,municipal,andautonomousregioncapitalstocitiesandcounties,betweencitiesandcounties,betweenneighboringprovincesandcounties,anddesignatedbytheTelecommunicationsAdministration.
3)Level3lines:refertocommunicationlinesbelowthecountylevel.Alsocalledlocalline.Forexample,intra-citycommunicationlinesaredividedintotwotypes:inter-officetrunklinesandsubscriberlines.Theinter-officetrunklinesincludeinter-officetrunklinesandlong-distanceandcity-officetrunklines.Subscriberlinescanbedividedintotwotypes:feederandwiring.
Ifdividedaccordingtotheapplicationareaofcommunicationlines,communicationlinescanalsobedividedintolong-distancelines,urbanlinesandrurallines.
Technology
Let'stalkabouttheseeminglysimplecommunicationline,butitisalongsection.Infact,thetechnologyofcommunicationlinesisnotassimpleasyouthink.Technically,communicationlinesincludematerialsscience,linetransmissiontechnology,manufacturingtechnology,designandconstructiontechnology,maintenancetechnology,andprotectiontechnology.Eachlinkisstillverytechnical,andthecommunicationlinetechnologycoversmultipledisciplines,includingmechanics,chemistry,meteorology,geology,biology,materials,mechanics,etc.Herewebrieflyintroduce:
1)Linetransmissiontechnology:Mainlyresearchandimprovetheperformanceoflinetransmissionsignals,whichcanensurethatthesignalcanbeeffectivelytransmittedalongtheline.Itinvolvesthepropagationofelectromagneticfields,electromagneticwaves,andmultipleconductors.Looptransmissionandothertechnologies.Thistechnologystudieshowtopreventtheelectromagneticcrosstalkbetweenthelinesortheoutsideintrusion,andcanensurethatthesignaltransmittedbyitselfisnotseverelyinterfered,soastoachievethereliabilityoftransmission.Itinvolveskeytechnologiessuchasopenwirecrossing,symmetricalcablebalance,andenvironmentalelectromagnetics.
2)Manufacturingtechnology:includingthefinalizeddesignofvariousequipmentofcommunicationlines(suchaswires,cables,opticalcables,poleequipment,pipes,connectingdevices,etc.),manufacturingprocesses,andrawmaterialsusedResearchanddevelopmentofperformance,etc.Atpresent,theproductionoflineequipment,especiallycommunicationopticalcablesandall-plasticcitycables,hasadoptedprocesstechnologysuchasprocesslinkageandcomputerautomaticcontrol,andtheproductionefficiencyhasbeengreatlyimproved.
3)Designandconstructiontechnology:Communicationlinesareoutdoorequipment,andtheirinstallationandlayingarerestrictedbynaturalconditionssuchasterrain,soilquality,andweather;atthesametime,thedistributionofresidentialareasandthegrowthrateofcommunicationtrafficarealsoaffectedbyhumanfactors.Willaffecttheconstructionanddevelopmentofcommunicationlines.Thedesignandconstructiontechnologyofcommunicationlineengineeringhasitsownuniquefeatures,anddifferentregionswilladoptdifferenttechnologiesaccordingly.Long-distancelinesurvey,openlinecrossmeasurement,businesspredictionandbureauplanningofintra-citytelecommunicationsnetwork,wiringsystem,cableducttechnology,symmetricalcablebalance,connectiontechnology,submarinecablelayout,etc.areallimportanttechnologiestoensurecommunicationlineengineering.
4)Linemaintenancetechnology:includesaseriesoftechnologiesandmethodssuchasinflationmaintenance,dailymaintenanceandobstaclehandling,andelectricaltesting.
5)Lineprotectiontechnology:includingstrongcurrentprotectiontechnology,lightningprotectiontechnology,linecorrosionprotectiontechnologyandpestprotectiontechnology.
Trends
Thedevelopmentofcommunicationlinesisalsoaprocessofcontinuousevolution,fromtheinitialoverheadopenwires,tosymmetricalcables,tocoaxialcables,andthentosubmarineopticalcables.Theelectricalandopticalsignalstransmittedinthelinearealsoconstantlychanging:theDCtelegraphsignalwasinitiallytransmitted;thenthevoiceband;andthentheanalogsignalinthecarrierfrequencybandwithafrequencyofseveraltensofmegahertzwastransmitted,andithasnowdevelopedtoabitrateofseveralDigitalsignalsofhundredsofmegabitsorevenseveralgigabitspersecond.Moreover,fiberopticcablesaregraduallyreplacingtraditionalopenwireorcoaxialcables.Withtherapiddevelopmentofnewmaterialsandnewtechnologies,thedevelopmentofcommunicationlineswilldefinitelybecomemoreexciting.
Collegeprofessionalsettings
Basicinformation
Professionalname:Communicationline
Professionalcode:590308
TrainingGoals
Studentsofthismajorwhohavepassedthesystemstudyandpracticeexamswillbetrainedtobecomemoderncommunicationenterprisesandrelatedenterprisesintheinstallationandmaintenanceofopticalfibertransmissionequipment,opticalcablelineconstructionandmaintenance,communicationengineeringdesign,andengineeringSupervisionandotherspecializedtalents;trainingtobecomeapplication-orientedspecializedtalentssuchasproduction,sales,technicalsupportandmaintenance,andtechnicalmanagementrequiredbycommunicationoperationenterprisesandcommunicationequipmentmanufacturingindustries.
Trainingrequirements
Masterthebasictheoreticalknowledgeofanaloganddigitalcircuitsandelectronics,haveasolidknowledgeofmoderncommunicationtechnology,andhavetheabilitytodesignandconstructcablesandopticalcables,andlineengineeringdesign.Andcomprehensiveprofessionalskillsintheinstallation,debuggingandmaintenanceofopticalfibercommunicationequipment,powersupplyequipmentandrelatedfields.
Maincourses
English,advancedmathematics,computerfoundation;circuitandsignal,communicationelectroniccircuit,digitallogiccircuit,databaseapplication;digitaldatacommunicationprinciple,opticalcablelineengineering,opticalfibercommunicationPrinciplesandequipment,communicationlineengineering,accessnetworktechnology,communicationpowersupply,communicationengineeringbudget;exchangetechnology,AutoCAD,mobilecommunicationprinciples,marketing,etc.
Professionaloverview
Theinter-officeconnectionofintra-citycommunicationsgenerallyusesopticalcablestotransmitinformation,butalsousesmicrowavecircuits;betweenthecommunicationsofficeandusers,mainlywireandcablelines.Thebroadbandofthecommunityisalsoconnectedbyopticalcablesandcables.
Itisanimportantpartofthenationalcommunicationnetwork,includingvariouscommunicationlineequipmentofthepostandtelecommunications,railway,militaryandotherdepartments.
Communicationlineequipment
Overheadline
——Pole,wire,cable,linearm,electronicisolation,pullwireandotherancillaryequipment.
Buriedlines
——Underground,underwater,seabed,pipelinesandcables,entryholes,markers,waterlinesigns,unmannedcarriersignalantennas,cablefillingstationsandOtherancillaryequipment.
Wirelessline
——Unmannedmicrowavestation,microwavepassivereflector,radioreceivingandtransmittingantenna,microwaveandsatellitecommunicationgroundstationwireless,antennafeedertower,Wires,waveguidesandotherancillaryequipment.
Regulationsoncommunicationlines
ProvisionsoftheStateCouncilandtheCentralMilitaryCommissionontheprotectionofcommunicationlines
[1982]No.28
Thefirstarticle
Thecommunicationlineisanimportantpartofthenationalcommunicationnetwork.Itisresponsibleforthedomesticandinternationalcommunicationtasksoftheparty,government,militaryandcivilians,andplaysanimportantroleinthesocialistmodernizationconstructionandtheconsolidationofnationaldefense.Inordertomakecommunicationunimpeded,thesafetyofcommunicationlinesmustbeensured.
Article2
Thisregulationisapplicabletovariouscommunicationlineequipmentofpostandtelecommunications,railway,militaryandotherdepartments.Thecommunicationlineequipmentincludes:
(1)Overheadlines-poles,wires,cables,linepoles,electronicisolation,pullwiresandotherancillaryequipment.
(2)Buriedlines-underground,underwater,submarine,pipelinesandcables,manholes,markers,waterlinesigns,unattendedcarrierboosterstations,cablechargingstationsandotherancillaryequipment.
(3)Wirelesscircuits-unattendedmicrowavestations,microwavepassivereflectors,radioreceivingandsignallingantennas,microwaveandsatellitecommunicationgroundstationantennas,antennafeedertowers,wires,waveguidesandOtherancillaryequipment.
Article3
People'sgovernmentsatalllevelsshouldstrengthentheleadershipoftheprotectionofcommunicationlines,andfrequentlycarryoutpublicityandeducationontheprotectionofcommunicationlines.Whennecessary,thesecurityorganizationsandmilitiaorganizationsofallunitsalongthelineshouldbeorganizedtoguardthelineforjointdefense.
Whencommunicationlinesaredamagedbynaturaldisastersorwars,people'sgovernmentsatalllevelsshouldimmediatelyorganizeforcestoassistcommunicationdepartmentsinrushrepairs.
Theagencies,factoriesandmines,troops,schools,communes,productionteamsandthepeoplealongthelineallhavetheresponsibilitytoprotectthesafetyofcommunicationlines.Allunitsandthepeoplehavetherighttostopactsthatdamagecommunicationlinesorendangercommunicationsafetyandshouldpromptlyreporttothelocalpublicsecurityorcommunicationdepartment.
Article4
Communicationdepartmentsandstaffatalllevelsshouldstrengthenthemaintenanceandmanagementofcommunicationlines,strictlyimplementthepostresponsibilitysystemandvariousrulesandregulations,strengthenpatrolinspections,andconductfrequentinspections.Protectlinepropaganda,keepclosecontactwithallunitsalongtheline,doagoodjobinlineprotectionjointdefense,andassistthepublicsecurityorgansindetectingcasesofsabotagingcommunicationlines.
Whenthecommunicationdepartmentneedstochangetheoriginalequipmentandfacilitiesofotherunits,exceptforemergencysituationssuchasrushingtorepairthecommunicationlineobstacles,itshouldobtaintheconsentoftherelevantunitinadvance,andberesponsiblefortherestorationaccordingtotheoriginalstandardafterwards,andbeartherequiredexpenses.Whenthecommunicationdepartmentsetsupacommunicationlinetopassthroughtheforestarea,itshouldnegotiatewiththerelevantdepartmentinadvance.
Article5
Stealingelectricalpoles,wires,cablesandothercommunicationlineequipmentorusingtechnicalmeanstoendangercommunicationsecurityisacrime.Casesinwhichthepublicsecurityandjudicialorgansdisruptedcommunicationlinesagainstcounter-revolutionariesandothercriminals.
Article6
ThewasterecyclingdepartmentshallstrictlyimplementthespiritofDocumentNo.275of1980oftheStateCouncil,andshallnotpurchasecommunicationlineequipmentsoldbythieves.Anyillegalactorsuspiciouscluesfoundinthepiratedorsoldcommunicationlineequipmentshallbereportedtothepublicsecurityorganorthecommunicationdepartmentintime.
Article7
Allunitsandthepeopleshallnotdamagecommunicationlineequipmentorconductactsthatendangercommunicationsafety.
(1)Blasting,stackingexplosiveandflammablematerialsorsettingupexplosiveandflammablematerialswarehouseswithintherangethatendangersthesafetyofcommunicationlinesisnotallowed.
(2)Itisnotallowedtodrillonthegroundwhereundergroundcablesareburied,pileupheavyobjects,garbage,slag,ordumpliquidscontainingacids,alkalis,andsalts.Diggingordiggingtrenchesonthegroundwhereundergroundcablesareburiedshouldberesolvedthroughconsultationwiththecommunicationsdepartment.
(3)Itisnotallowedtodropanchors,draganchors,digsand,fryfishandperformotheroperationsthatendangerthesafetyofcablesinthewaterswheretherearesignsofcross-rivercables.(4)Itisnotallowedtodropanchors,towanchors,trawlfishing,orperformotheroperationsthatendangerthesafetyofthesubmarinecablesinthewatersoftwonauticalmilesoneachsideofthesubmarinecablepositionindicatedonthechart(100metersoneachsideintheport).
(5)Itisnotallowedtobuildhousesandscaffoldswithinonemeteronbothsidesoftheundergroundcable,anditisnotallowedtodigsandandearthandsetuptoilets,manuretanks,livestockpens,andbiogaswithinthreemeterseach.Buildingssuchaspoolsthatcancausecablecorrosion.Treesandbamboosarenotallowedtobeplantedwithintherangeof2metersoneachsideofthecableoutsidetheurbanareaand0.75metersoneachsideofthecableintheurbanarea.
(6)Itisforbiddentomoveordamageelectricpoles,pullwires,antennas,antennafeedertowers,andunattendedcarrierboosterstationsandmicrowavestations.
(7)Itisnotallowedtotakesoilandbuildshedsonbothsidesofoverheadlinesorintheantennaareawithintherangethatendangersthesafetyofpolesandcables.
(8)Itisnotallowedtoclimbelectricpoles,antennamasts,cablesandotherancillaryequipment.
(9)Itisnotallowedtotiecattletopoles,pullwires,antennas,antennafeedertowers,bracketsandotherancillaryequipment;HangtheradiospeakersandantennasfortheradioandTV.
Article8
Buildingconstruction,roadconstruction,waterconservancyconstruction,farmlandconstruction,treeplantingandafforestation,fellingoftreesandbamboo,transportationofsuper-highandsuper-largeobjects,erectionoflines,Layingpipelinesandperformingunderwateroperations,etc.,ifthereisapossibilityofendangeringthesafetyofcommunicationlines,thecommunicationdepartmentshouldbeagreedinadvance,andtechnicalprecautionscanbetakenbeforeconstructioncanbestarted.
Forbranchesthatendangerthesafetyofcommunicationlines,thecommunicationdepartmentshouldconsultwiththerelevantdepartmentstoremovethemfreeofcharge.Thecommunicationsdepartmentcantrimthetreesandbamboosthathaveaffectedthecommunicationlinesbuthavenotbeenpruned.
Article9
Intheconstructionofcommunicationlines,thesafety,reliability,andeconomyofthelinesshouldbeconsidered,andtheimpactonexistingbuildingsandfacilitiesshouldbeavoidedasmuchaspossible.Allnewlybuiltcommunicationlinesincities,towns,counties,andindustrialandminingareasshouldbeincorporatedintothecomprehensiveplanningofmunicipalpipelines,andbeconstructedinsyncwithroadsandotherpipelinenetworksasmuchaspossible.Electricpolesandcablesshouldbeusedtosavelandasmuchaspossible,occupylessornofarmland,andusetherequiredlandfreeofcharge.
Cropsandforestsshouldbetakencareofduringtheconstructionandmaintenanceofcommunicationlines;youngcropsandforestsshouldbedamagedduringconstructionandcompensationshouldbemadeaccordingtoregulations.
Article10
Generally,communicationlinescannotbechanged.Whenotherunitshavetorelocatetheircommunicationlinesunderspecialcircumstances,theyshallfirstobtaintheapprovalofthecommunicationsdepartment,andthecostandmaterialsrequiredfortherelocationprojectshallbebornebytheunitthatproposedtherelocation.
Article11
Anyunitorindividualwhoviolatestheseregulationsandcausesdamagetothelineorinterruptionofcommunicationshallbeorderedtobearthecostofrepairingthelineandcompensatethecommunicationstationthatblockedthecommunication.Theeconomiclossescausedwillcontinuetobeinvestigatedforcriminalresponsibilityinaccordancewiththelaw.Violationofthisregulation,althoughthecommunicationlinehasnotbeendamaged,butthesafetyofthecommunicationlinehasbeenendangered,thecommunicationdepartmentshalldissuadeorstopit;whennecessary,thepublicsecurityorganshallcooperatewiththecommunicationdepartmenttodissuadeorstopit.
Article12
Forunitsthathavemadeoutstandingachievementsinprotectingcommunicationlines,preventingdamageaccidents,assistingindetectingcases,capturingcriminals,recoveringstolencommunicationequipment,andassistinginrushingtorepaircommunicationlines,Collectivesandindividualsshallbecommendedorrewardedbythecommunicationsdepartment.
Article13
Theseregulationsshallcomeintoforceonthedateofpromulgation.Ifthepreviousrelevantregulationsconflictwiththisregulation,thisregulationshallprevail.