手机火车汉字发展史英文版

手机火车汉字发展史英文版手机发展史英文版Thehistoryofmobilephonesbeginswithearlyeffortstodevelopradiotelephonetechnologyandfromtwo-wayradiosinvehiclesandcontinuesthroughemergenceofmodernmobilephonesandassociatedservices.RadiophoneshavealongandvariedhistorygoingbacktoReginaldFessenden'sinventionandshore-to-shipdemonstrationofradiotelephony,throughtheSecondWorldWarwithmilitaryuseofradiotelephonylinksandcivilservicesinthe1950s,whilehand-heldmobileradiodeviceshavebeenavailablesince1973.Mobilephonehistoryisoftendividedintogenerations(first,second,thirdandsoon)tomarksignificantstepchangesincapabilitiesasthetechnologyimprovedovertheyears.Contents[hide]1Pioneersofradiotelephony2Emergenceofcommercialmobilephoneservices3Firstgeneration:Cellularnetworks4Secondgeneration:Digitalnetworks5Thirdgeneration:HighspeedIPdatanetworks6Growthofmobilebroadbandandtheemergenceof4G7Patents8Seealso9Notes10References11Externallinks[edit]PioneersofradiotelephonyIn1908,U.S.Patent887,357forawirelesstelephonewasissuedtoNathanB.StubblefieldofMurray,Kentucky.Heappliedthispatenttocaveradiotelephonesandnotdirectlytocellulartelephonyasthetermiscurrentlyunderstood.[1]In1910LarsMagnusEricssoninstalledatelephoneinhiscar,althoughthiswasnotaradiotelephone.Whiletravellingacrossthecountry,hewouldstopataplacewheretelephonelineswereaccessibleandusingapairoflongelectricwireshecouldconnecttothenationaltelephonenetwork.[2]InEurope,radiotelephonywasfirstusedonthefirst-classpassengertrainsbetweenBerlinandHamburgin1926.Atthesametime,radiotelephonywasintroducedonpassengerairplanesforairtrafficsecurity.LaterradiotelephonywasintroducedonalargescaleinGermantanksduringtheSecondWorldWar.AfterthewarGermanpoliceintheBritishzoneofoccupationfirstuseddisusedtanktelephonyequipmenttorunthefirstradiopatrolcars.[citationneeded]Inallofthesecasestheservicewasconfinedtospecialiststhatweretrainedtousetheequipment.Intheearly1950sshipsontheRhinewereamongthefirsttouseradiotelephonywithanuntrainedendcustomerasauser.Two-wayradios(knownasmobilerigs)wereusedinvehiclessuchastaxicabs,policecruisers,andambulances,butwerenotmobilephonesbecausetheywerenotnormallyconnectedtothetelephonenetwork.Userscouldnotdialphonenumbersfromtheirvehicles.Alargecommunityofmobileradiousers,knownasthemobileers,popularizedthetechnologythatwouldeventuallygivewaytothemobilephone.Originally,mobiletwo-wayradioswerepermanentlyinstalledinvehicles,butlaterversionssuchastheso-calledtransportablesorbagphoneswereequippedwithacigarettelighterplugsothattheycouldalsobecarried,andthuscouldbeusedaseithermobileorasportabletwo-wayradios.Duringtheearly1940s,Motoroladevelopedabackpackedtwo-wayradio,theWalkie-Talkieandlaterdevelopedalargehand-heldtwo-wayradiofortheUSmilitary.ThisbatterypoweredHandie-Talkie(HT)wasaboutthesizeofaman'sforearm.In1946sovietengineersG.ShapiroandI.Zaharchenkosuccessfullytestedtheirversionofaradiomobilephonemountedinsideacar.Thedevicecouldconnecttolocaltelephonenetworkwitharangeofupto20kilometers.TopofcellulartelephonetowerInDecember1947,DouglasH.RingandW.RaeYoung,BellLabsengineers,proposedhexagonalcellsformobilephonesinvehicles.[3]PhilipT.Porter,alsoofBellLabs,proposedthatthecelltowersbeatthecornersofthehexagonsratherthanthecentersandhavedirectionalantennasthatwouldtransmit/receiveinthreedirections(seepictureatright)intothreeadjacenthexagoncells.[4]Thetechnologydidnotexistthenandthefrequencieshadnotyetbeenallocated.Cellulartechnologywasundevelopeduntilthe1960s,whenRichardH.FrenkielandJoelS.EngelofBellLabsdevelopedtheelectronics.Duringthe1950stheexperimentsofthepioneersstartedtoappearasusableservicesacrosssociety,bothcommerciallyandculturally.Inthe1954movieSabrina,thebusinessmanLinusLarrabee(playedbyHumphreyBogart)makesacallfromthephoneinthebackofhislimousine.In1957youngSovietradioengineerLeonidKupriyanovichfromMoscowcreatedtheportablemobilephone,namedafterhimselfasLK-1orradiophone.[5]Thistruemobilephoneconsistedofarelativelysmall-sizedhandsetequippedwithanantennaandrotarydial,andcommunicatedwithabasestation.Kupriyanovich'sradiophonehad3kilogramoftotalweight,couldoperateupto20or30kilometers,andhad20or30hoursofbatterylifespan.LK-1anditslayoutwasdepictedinpopularSovietmagazinesasNaukaizhizn,8,1957,p.49,Yuniytechnik,7,1957,p.43–44.EngineerKupriyanovichpatentedhismobilephoneinthesameyear1957(author'scertificate(USSRPatent)#115494,1.11.1957).ThebasestationofLK-1(calledATR,orAutomatedTelephoneRadiostation)couldconnecttolocaltelephonenetworkandserveseveralcustomers.In1958,Kupriyanovichresizedhisradiophonetopocketversion.Theweightofimprovedlighthandsetwasabout500grams.In1967,eachmobilephonehadtostaywithinthecellareaservicedbyonebasestationthroughoutthephonecall.Thisdidnotprovidecontinuityofautomatictelephoneservicetomobilephonesmovingthroughseveralcellareas.In1969,apatentforawirelessphoneusinganacousticcouplerforincomingcallswasissuedinUSPatentNumber3,449,750toGeorgeSweigertofEuclid,OhioonJune10,1969.Dialinganumberforoutgoingcallswasnotprovided.Theconceptsoffrequencyreuseandhandoff,aswellasanumberofotherconceptsthatformedthebasiso