BOOK8-Unit3Inventorsandinventions“百校聯(lián)賽”一等獎(jiǎng)

Mobilephone

Severalexamplesofnon-foldingmobilephones.

Themobilephoneorcellphoneisalong-range,portableelectronicdeviceusedformobilecommunication.Inadditiontothestandardvoicefunctionofatelephone,currentmobilephonescansupportmanyadditionalservicessuchasSMSfortextmessaging,email,packetswitchingforaccesstotheInternet,andMMSforsendingandreceivingphotosandvideo.Mostcurrentmobilephonesconnecttoacellularnetworkofbasestations(cellsites),whichisinturninterconnectedtothepublicswitchedtelephonenetwork(PSTN)(theexceptionissatellitephones).

History

Variouscellphonesfromthepast10–15years.

Legend:

1.NECCellstar500series(1992)

2.Nokia2110series(1994)

3.Nokia5120(1998)

4.Kyocera2135(2002)

5.AudiovoxCDM8300(2002)

6.SamsungSCH-A650(2004)

ThereisoneU.S.patent,PatentNumber887357forawirelesstelephone,issued1908toNathanB.StubblefieldofMurray,Kentucky.Heappliedthisto"caveradio"telephonesandnotdirectlytocellulartelephonyasweknowittoday.However,theintroductionofcellsformobilephonebasestations,inventedin1947byBellLabsengineersatAT&T,wasfurtherdevelopedbyBellLabsduringthe1960s.RadiophoneshavealongandvariedhistorygoingbacktoReginaldFessenden'sinventionandshore-to-shipdemonstrationofradiotelephony,throughtheSecondWorldWarwithmilitaryuseofradiotelephonylinksandcivilservicesinthe1950s,whilehand-heldcellularradiodeviceshavebeenavailablesince1983.Duetotheirlowestablishmentcostsandrapiddeployment,mobilephonenetworkshavesincespreadrapidlythroughouttheworld,outstrippingthegrowthoffixedtelephony.

In1945,thezerogeneration(0G)ofmobiletelephoneswasintroduced.0Gmobiletelephones,suchasMobileTelephoneService,werenotofficiallycategorizedasmobilephones,sincetheydidnotsupporttheautomaticchangeofchannelfrequencyduringcalls,whichallowstheusertomovefromonecell(thebasestationcoveragearea)toanothercell,afeaturecalled"handover".

In1984,BellLabsinventedsucha"callhandoff"feature,whichallowedmobile-phoneuserstotravelthroughseveralcellsduringthesameconversation.Motorolaiswidelyconsideredtobetheinventorofthefirstpracticalmobilephoneforhandhelduseinanon-vehiclesetting.Usingamodern,ifsomewhatheavyportablehandset,MotorolamanagerMartinCoopermadethefirstcallonahandheldmobilephoneonApril3,1973.

ThefirstcommercialcellularnetworkwaslaunchedinJapanbyNTTin1979.Fullyautomaticcellularnetworkswerefirstintroducedintheearlytomid1980s(the1Ggeneration)withtheNordicMobileTelephone(NMT)systemin1981.Thiswasfollowedbyaboominmobiletelephoneusage,particularlyinNorthernEurope.

Thefirst"modern"networktechnologyondigital2G(secondgeneration)cellulartechnologywaslaunchedbyRadiolinja(nowpartofElisaGroup)in1991inFinlandontheGSMstandardwhichalsomarkedtheintroductionofcompetitioninmobiletelecomswhenRadiolinjachallengedincumbentTelecomFinland(nowpartofTeliaSonera)whorana1GNMTnetwork.Adecadelater,thefirstcommerciallaunchof3G(ThirdGeneration)wasagaininJapanbyNTTDoCoMoontheWCDMAstandard.Untiltheearly1990s,mostmobilephonesweretoolargetobecarriedinajacketpocket,sotheyweretypicallyinstalledinvehiclesascarphones.Withtheminiaturizationofdigitalcomponents,mobilephoneshavebecomeincreasinglyhandyovertheyears.

Manufacturers

Themobilephonemanufacturerscanbegroupedintotwo.Thetopfiveareavailableinpracticallyallcountriesandcompriseabout75%ofallphonessold.Asecondtierofsmallmanufacturersexistswithphonesmostlysoldonlyinspecificregionsorfornichemarkets.ThetopfiveinorderofmarketshareareNokia,Motorola,Samsung,SonyEricssonandLG.

NokiaCorporationiscurrentlytheworld'slargestmanufacturerofmobiletelephones,withaglobaldevicemarketshareofapproximately36%inQ1of2007.OthermobilephonemanufacturersincludeAppleInc.,Audiovox(nowUTStarcom),Benefon,BenQ-Siemens,HighTechComputerCorporation(HTC),Fujitsu,Kyocera,LGMobile,Mitsubishi,Motorola,NEC,Neonode,Panasonic(MatsushitaElectric),PantechCuritel,Philips,ResearchInMotion,Sagem,Samsung,Sanyo,Sharp,Siemens,SierraWireless,SKTeletech,SonimTechnologies,SonyEricsson,T&AAlcatel,Toshiba,andVerizon.Therearealsospecialistcommunicationsystemsrelatedto(butdistinctfrom)mobilephones.

Subscriptions

ThisRailfonefoundonsomeAmtraktrainsusescellulartechnology.

Severalcountries,includingtheUK,nowhavemoremobilephonesthanpeople.ThereareoverfivehundredmillionactivemobilephoneaccountsinChina,asof2007.Luxembourghasthehighestmobilephonepenetrationrateintheworld,at164%inDecember2001.InHongKongthepenetrationratereached117%ofthepopulationinSeptember2004.Thetotalnumberofmobilephonesubscribersintheworldwasestimatedatbillionin2005.Thesubscribercountreachedbillionbyendof2006accordingtoInforma.Around80%oftheworld'spopulationenjoysmobilephonecoverageasof2006.Thisfigureisexpectedtoincreaseto90%bytheyear2010.

Atpresent,Africahasthelargestgrowthrateofcellularsubscribersintheworld,itsmarketsexpandingnearlytwiceasfastasAsianmarkets.Theavailabilityofprepaidor'payasyougo'services,wherethesubscriberisnotcommittedtoalongtermcontract,hashelpedfuelthisgrowthtoamonumentalscaleinAfricaaswellasinothercontinents.

Onanumericalbasis,Indiaisthelargestgrowthmarket,addingabout6millioncellphoneseverymonth.Withmillioncellphones,marketpenetrationinthecountryisstilllowat%Indiaexpectstoreach500millionsubscribersbyendof2010.

Therearethreemajortechnicalstandardsforthecurrentgenerationofmobilephonesandnetworks,andtwomajorstandardsforthenextgeneration3Gphonesandnetworks.AllEuropeancountriesandAfricancountriesandmanyAsiancountrieshaveadoptedasinglesystem,GSM,whichistheonlytechnologyavailableonallcontinentsandinmostcountriesandcoversover74%ofallsubscribersonmobilenetworks.Inmanycountries,suchastheUnitedStates,Australia,Brazil,India,Japan,andSouthKoreaGSMco-existswithotherinternationallyadoptedstandardssuchasCDMAandTDMA,aswellasnationalstandardssuchasiDENintheUSAandPDCinJapan.Overthepastfiveyearsseveraldozenmobileoperators(carriers)haveabandonednetworksonTDMAandCDMAtechnologies,switchingovertoGSM.

Withthirdgeneration(3G)networks,whicharealsoknownasIMT-2000networks,aboutthreeoutoffournetworksareontheWCDMA(alsoknownasUMTS)standard,usuallyseenasthenaturalevolutionpathforGSMandTDMAnetworks.Oneinfour3GnetworksisontheCDMA20001xEV-DOtechnology.SomeanalystscountapreviousstageinCDMAevolution,CDMA20001xRTT,asa3GtechnologywhereasmoststandardizationexpertscountonlyCDMA20001xEV-DOasatrue3Gtechnology.Becauseofthisdifferenceininterpretingwhatis3G,thereisawidevarietyinsubscribercounts.AsofJune2007,onthenarrowdefinitionthereare200millionsubscriberson3Gnetworks.Byusingthemorebroaddefinition,thetotalsubscribercountof3Gphoneusersis475million.

Whilesomesystemsofpaymentare'payasyougo'whereconversationtimeispurchasedandaddedtoaphoneunitviaanInternetaccountorinshopsorATMs,othersystemsaremoretraditionaloneswherebillsarepaidbyregularintervals.Payasyougo(alsoknownas"pre-pay")accountswereinventedsimultaneouslyinPortugalandItalyandtodayformmorethanhalfofallmobilephonesubscriptions.USA,Canada,JapanandFinlandareamongtherarecountriesleftwheremostphonesarestillcontract-based.

Cultureandcustoms

Inlessthantwentyyears,themobiletelephonehasgonefrombeingrare,expensiveequipmentofthebusinesselitetoapervasive,low-costpersonalitem.Inmanycountries,mobiletelephonesoutnumberland-linetelephones;intheU.S.,50percentofchildrenhavemobiletelephones.Inmanyyoungadults'householdsithassupplantedtheland-linetelephone.Themobilephoneisbannedinsomecountries,suchasNorthKorea.

Giventhehighlevelsofsocietalmobiletelephoneservicepenetration,itisakeymeansforpeopletocommunicatewitheachother.TheSMSfeaturespawnedthe"texting"sub-culture.InDecember1993,thefirstperson-to-personSMStextmessagewastransmittedinFinland.Currently,textingisthemostwidely-useddataservice;billionusersgenerated$80billionofrevenuein2006(sourceITU).

ManytelephonesofferInstantMessengerservicesforsimple,easytexting.MobilephoneshaveInternetservice.NTTDoCoMo'si-mode),offeringtextmessagingviae-mailinJapan,SouthKorea,China,andIndia.InEurope,30–40percentofinternetaccessisviamobiletelephone.Mostmobileinternetaccessismuchdifferentfromcomputeraccess,featuringalerts,weatherdata,e-mail,searchengines,instantmessages,andgameandmusicdownloading;mostmobileinternetaccessishurriedandshort.

Currently,themobiletelephoneisafashiontotemcustom-decoratedtoreflecttheowner'spersonality.Thisaspectofthemobiletelephonybusinessis,initself,anindustry,.ringtonesalesexceeded$5billionin2006,perInforma.

Etiquette

Theuseofamobilephoneisprohibitedinsometraincompanycarriages

Mobiletelephoneuseetiquetteisanimportantmatterofsocialdiscourtesy,phonesringingduringfunerals,weddings,intoilets,cinemas,andplays.Usersoftenspeakloudly,leadingtobookshops,libraries,bathrooms,cinemas,doctors'offices,andhousesofworshipprohibitingtheiruses,and,insomeplaces,theinstallationofsignal-jammingequipmenttopreventtheiruse(thoughinmanycountries,includingthe.,suchequipmentiscurrentlyillegal).Somenewbuildings,suchasauditoriums,haveinstalledwiremeshinthewalls(makingitaFaradaycage)whichpreventssignalpenetrationthatdoesnotviolatesignaljamminglaws.

Trains,particularlythoseinvolvinglong-distanceservices,oftenoffera"quietcar"wherephoneuseisprohibited,muchlikethedesignatednon-smokingcarinthepast.Howevermanyuserstendtoignorethisasitisrarelyenforced,especiallyiftheothercarsarecrowdedandtheyhavenochoicebuttogointhe"quietcar".Mobilephoneuseonaircraftisalsoprohibitedandmanyairlinesclaimintheirin-planeannouncementsthatthisprohibitionisduetopossibleinterferencewithaircraftradiocommunications.Shut-offmobilephonesdonotinterferewithaircraftavionics.Thenuisanceoftelephonesonwhileaeroplanestakeoffandland,isthattheydisruptthegroundmobiletelephonenetworks.

Ascustomerswanttobeconnectedonplanes,nowseveralairlinesareexperimentingwithbasestationandantennasystemsinstalledtotheaeroplane,allowinglowpower,short-rangeconnectionofanyphonesaboardtoremainconnectedtotheaircraft'sbasestation.Thus,theywouldnotattemptconnectiontothegroundbasestationsasduringtakeoffandlanding.Simultaneously,airlinescouldofferphoneservicestotheirtravelingpassengerseitherasfullvoiceanddataservices,orinitiallyonlyasSMStextmessagingandsimilarservices.Qantas,theAustralianairline,isthefirstairlinetorunatestairplaneinthisconfigurationintheAutumnof2007.Emirateshaveannouncedplanstoallowlimitedmobilephoneusageonsomeflights.

Inanycase,thereareinconsistenciesbetweenpracticesallowedbydifferentairlinesandevenonthesameairlineindifferentcountries.Forexample,NorthwestAirlinesmayallowtheuseofmobilephonesimmediatelyafterlandingonadomesticflightwithintheUS,whereastheymaystate"notuntilthedoorsareopen"onaninternationalflightarrivingintheNetherlands.InApril2007theUSFederalCommunicationsCommissionofficiallygroundedtheideaofallowingpassengerstousephonesduringaflight.

Inasimilarvein,signsareputupinUKpetrolstationsprohibitingtheuseofmobilephones,duetopossiblesafetyissues.MostschoolsintheUnitedStateshaveprohibitedmobilephonesintheclassroom,duetothelargenumberofclassdisruptionsthatresultfromtheiruse,thepotentialforcheatingviatextmessaging,andthepossibilityofphotographingsomeonewithoutconsent.IntheUK,possessionofamobilephoneinanexaminationcanresultinimmediatedisqualificationfromthatsubjectorfromallthatstudent'ssubjects.

Useindisasterresponse

TheFinnishgovernmentdecidedin2005thatthefastestwaytowarncitizensofdisasterswasthemobilephonenetwork.InJapan,mobilephonecompaniesprovideimmediatenotificationofearthquakesandothernaturaldisasterstotheircustomersfreeofcharge.Intheeventofanemergency,disasterresponsecrewscanlocatetrappedorinjuredpeopleusingthesignalsfromtheirmobilephones.Aninteractivemenuaccessiblethroughthephone'sInternetbrowsernotifiesthecompanyiftheuserissafeorindistress.InFinlandrescueservicessuggesthikerscarrymobilephonesincaseofemergencyevenwhendeepintheforestsbeyondcellularcoverage,astheradiosignalofacellphoneattemptingtoconnecttoabasestationcanbedetectedbyoverflyingrescueaircraftwithspecialdetectiongear.Also,usersintheUnitedStatescansignupthroughtheirproviderforfreetextmessageswhenanAmberAlertgoesoutforamissingpersonintheirarea.

Usebydrivers

Onephoneineachhand

Mobile-phoneusewhiledrivingiscommonbutcontroversial.Whilefewjurisdictionshavebannedmotoristsfromusingmobilephoneswhiledrivingoutright,somehavebannedorrestricteddriversfromusinghand-heldmobilephoneswhileexemptingphonesoperatedinahands-freefashion.Usingahand-heldmobilephonewhiledrivingisanimpedimenttovehicleoperationthatcanincreasetheriskofroadtrafficaccidents.However,somestudieshavefoundsimilarlyelevatedaccidentratesamongdriversusinghands-freephones,suggestingthatthedistractionofatelephoneconversationitselfisasignificantsafetyproblem.Thisproblemdoesnotapplytoconversationswithapassenger,aspassengerscanregulatetheflowofconversationaccordingtotheperceivedlevelofdanger,andalsoprovidesasecondpairofeyestospothazards.

Applications

Mobilenewsservicesareexpandingwithmanyorganizationsproviding"on-demand"newsservicesbySMS.Somealsoprovide"instant"newspushedoutbySMS.MobiletelephonyalsofacilitatesactivismandpublicjournalismbeingexploredbyReutersandYahooandsmallindependentnewscompaniessuchasJasmineNewsinSriLanka.CompanieslikeMonsterarestartingtooffermobileservicessuchasjobsearchandcareeradvice.Consumerapplicationsareontheriseandincludeeverythingfrominformationguidesonlocalactivitiesandeventstomobilecouponsanddiscountoffersonecanusetosavemoneyonpurchases.Eventoolsforcreatingwebsitesformobilephonesareincreasinglybecomingavailable,.Mobilemo.

Thetotalvalueofmobiledataservicesexceedsthevalueofpaidservicesontheinternet,andwasworth31billiondollarsin2006(sourceInforma).Thelargestcategoriesofmobileservicesaremusic,picturedownloads,videogaming,adultentertainment,gambling,video/TV.

Power

Mobilephonesgenerallyobtainpowerfrombatterieswhichcanberechargedfrommainspower,aUSBportoracigarettelightersocketinacar.Formerly,themostcommonformofcellphonebatterieswerenickelmetal-hydride,astheyhavealowsizeandweight.Lithium-Ionbatteriesaresometimesused,astheyarelighteranddonothavethevoltagedepressionthatnickelmetal-hydridebatteriesdo.Manymobilephonemanufacturershavenowswitchedtousinglithium-PolymerbatteriesasopposedtotheolderLithium-Ion,themainadvantagesofthisbeingevenlowerweightandthepossibilitytomakethebatteryashapeotherthanstrictcuboid.Cellphonemanufacturershavebeenexperimentingwithalternatepowersources.

Features

Therearesignificantquestionsastowhofirstinventedthecameraphone,asnumerousotherpeoplereceivedpatentsfiledintheearly1990sforthedevice,includingDavidM.BritzofAT&TResearchinMarchof1994andPhillipeKahn,whoclaimstohavefirstinventeditin1997.Thecameraphonenowholds85%ofthemobilephonemarket.Mobilephonesoftenhavefeaturesbeyondsendingtextmessagesandmakingvoicecalls,includingInternetbrowsing,music(MP3)playback,memorecording,personalorganizerfunctions,e-mail,instantmessaging,built-incamerasandcamcorders,ringtones,games,radio,Push-to-Talk(PTT),infraredandBluetoothconnectivity,callregisters,abilitytowatchstreamingvideoordownloadvideoforlaterviewing,videocallingandserveasawirelessmodemforaPC,andsoonwillalsoserveasaconsoleofsortstoonlinegamesandotherhighqualitygames.FinalFantasyAgito).

Whencellulartelecomsserviceswerelaunched,phonesandcallswereveryexpensiveandearlymobileoperators(carriers)decidedtochargeforallairtimeconsumedbythemobilephoneuser.Thisresultedintheconceptofchargingcallersforoutboundcallsandalsoforreceivingcalls.Asmobilephonecallchargesdiminishedandphoneadoptionratesskyrocketed,moremodernoperatorsdecidednottochargeforincomingcalls.Thussomemarketshave"ReceivingPartyPays"models,inwhichbothoutboundandreceivedcallsarecharged,andothermarketshave"CallingPartyPays"models,bywhichonlymakingcallsproducescosts,andreceivingcallsisfree.Anexceptiontothisisinternationalroaming,bywhichalsoreceivingcallsisnormallyalsocharged.

TheEuropeanmarketadopteda"CallingPartyPays"modelthroughouttheGSMenvironmentandsoonvariousotherGSMmarketsalsostartedtoemulatethismodel.AsReceivingPartyPayssystemshavetheundesiredeffectofphoneownerskeepingtheirphonesturnedofftoavoidreceivingunwantedcalls,thetotalvoiceusagerates(andprofits)inCallingPartyPayscountriesoutperformthoseinReceivingPartyPayscountries.Consequently,mostcountriespreviouslywithReceivingPartyPaysmodelshaveeitherabandonedthemoremployedalternativemarketingmethods,suchasmassivevoicecallbuckets,toavoidtheproblemofphoneuserskeepingphonesturnedoff.

Inmostcountriestoday,includingEuropeanUnionnations,UnitedArabEmirates,Kazakhstan,Turkey,NewZealand,Korea,Japan,Pakistan,Australia,Brazil,Chile,Colombia,India,Maldives,Peru,SouthAfrica,Israel,LebanonandJordanthepersonreceivingamobilephonecallpaysnothing.However,inHongKong,Canada,andtheUnitedStates,onecanbechargedperminute.IntheUnitedStates,afewcarriersarebeginningtoofferunlimitedreceivedphonecalls.FortheChinesemainland,itwasreportedthatbothofitstwooperatorswilladoptthecaller-paysapproachasearlyasJanuary2007.

Developingcountries

Insomedevelopingcountrieswithlittletelephoneinfrastructure,themobiletelephoneisthetelephonygivingpoorpeopleaccesstomedicalandlegalservices.Cellphoneuseindevelopingcountrieshasquadrupledinthelastdecade.Theriseofcellphonetechnologyindevelopingcountriesisoftencitedasanexampleoftheleapfrogeffect.Inmanyremoteregionsinthethirdworldwentliterallyfromhavingnotelecommunicationsinfrastructuretohavingsatellitebasedcommunicationssystems.

Forensicsandevidence

Lawenforcementgloballyrelyheavilyuponmobiletelephoneevidence,totheextentthatintheEUthe"communicationsofeverymobiletelephoneuserarerecorded".TheconcernsoverterrorismandterroristuseoftechnologypromptedaninquirybytheBritishHouseofCommonsHomeAffairsSelectCommitteeintotheuseofevidencefrommobiletelephonedevices,promptingleadingmobiletelephoneforensicspecialiststoidentifyforensictechniquesavailableinthisarea.NISThavepublishedguidelinesandproceduresforthepreservation,acquisition,examination,analysis,andreportingofdigitalinformationpresentoncellphonescanbefoundundertheNISTPublicationSP800-101.

Anexampleofcriminalinvestigationsusingmobilephonesistheinitiallocationandultimateidentificationoftheterroristsofthe2004Madridtrainbombings.Intheattacks,mobilephoneshadbeenusedtodetonatethebombs.However,oneofthebombsfailedtodetonate,andtheSIMcardinthecorrespondingmobilephonegavethefirstseriousleadabouttheterroriststoinvestigators.BytrackingthewhereaboutsoftheSIMcardandcorrelatingothermobilephonesthathadbeenregisteredinthoseareas,policewereabletolocatetheterrorists.

Humanhealthimpacts

Sincetheintroductionofmobilephones,concernshavebeenraisedaboutthepotentialhealthimpactsfromregularuse.Asmobilephonepenetrationsgrewpastfixedlandlinepenetrationlevelsin1998inFinlandandfrom1999inSweden,DenmarkandNorway,theScandinavianhealthauthoritieshaveruncontinuouslongtermstudiesofeffectsofmobilephoneradiationeffectstohumans,andinparticularchildren.Numerousstudieshavereportedandmoststudiesconsistentlyreportnosignificantrelationshipbetweenmobilephoneuseandhealth.StudiesfromtheInstituteofCancerResearch,NationalCancerInstituteandresearchersattheDanishInstituteofCancerEpidemiologyinCopenhagenforexampleshowednolinkbetweenmobilephoneuseandcancer.TheDanishstudyonlycoveredanalogmobilephoneusageupthrough1995,andsubjectswhostartedmobilephoneusageafter1995werecountedasnon-usersinthestudy.ThehealthconcernshavegrownasmobilephonepenetrationratesthroughoutEuropereached80%–90%levelsearlierinthisdecadeandprolongedexposurestudieshavebeencarriedoutinalmostallEuropeancountriesagainmostreportingnoeffect,andthemostalarmingstudiesonlyreportingapossibleeffect.However,astudybytheInternationalAgencyforResearchonCancerof4,500usersfoundastatisticallysignificantlinkbetweentumorfrequencyandmobilephoneuse.

ThemanylinkstocellphonesandspermqualityofcauseisastrongscientificallyevidencethattheradiationemittingfromMobilephonesalwaysshouldbeconsideredaspotentiallydangerous,evenifwedon'tknowallthemechanismbehindthealreadyknowndangerstolivingcellsandorganisms.

Environmentalimpacts

Likeallhighstructures,cellularantennamastsposeahazardtolowflyingaircraft.Towersoveracertainheightortowersthatareclosetoairportsorheliportsarenormallyrequiredtohavewarninglights.Therehavebeenreportsthatwarninglightsoncellularmasts,TV-towersandotherhighstructurescanattractandconfusebirds.USauthoritiesestimatethatmillionsofbirdsarekillednearcommunicationtowersinthecountryeachyear.

Anexampleofthewaymobilephonesandmobilenetworkshavesometimesbeenperceivedasathreatisthewidelyreportedandlaterdiscreditedclaimthatmobilephonemastsareassociatedwiththe"ColonyCollapseDisorder"(CCD)whichhasreducedbeehivenumbersbyupto75%inmanyareas,especiallynearcitiesintheUS.TheIndependentnewspapercitedascientificstudyclaimingitprovidedevidenceforthetheorythatmobilephonemastsareamajorcauseinthecollapseofbeepopulations,withcontrolledexperimentsdemonstratingarapidandcatastrophiceffectonindividualhivesnearmasts.Mobilephoneswereinfactnotcoveredinthestudy,andtheoriginalresearchershavesinceemphatica