Wireless-Communications無(wú)線通信-畢業(yè)設(shè)計(jì)論文-外文文獻(xiàn)翻譯

WirelessCommunications*byJoshuaS.Gans,StephenP.KingandJulianWright1.IntroductionIn1895,GuglielmoMarconiopenedthewayformodernwirelesscommunicationsbytransmittingthethree-dotMorsecodefortheletter‘S’overadistanceofthreekilometersusingelectromagneticwaves.Fromthisbeginning,wirelesscommunicationshasdevelopedintoakeyelementofmodernsociety.Fromsatellitetransmission,radioandtelevisionbroadcastingtothenowubiquitousmobiletelephone,wirelesscommunicationshasrevolutionizedthewaysocietiesfunction.Thischaptersurveystheeconomicsliteratureonwirelesscommunications.Wirelesscommunicationsandtheeconomicgoodsandservicesthatutiliseithavesomespecialcharacteristicsthathavemotivatedspecialisedstudies.First,wirelesscommunicationsreliesonascarceresource–namely,radiospectrum–thepropertyrightsforwhichweretraditionallyvestedwiththestate.Inordertofosterthedevelopmentofwirelesscommunications(includingtelephonyandbroadcasting)thoseassetswereprivatised.Second,useofspectrumforwirelesscommunicationsrequiredthedevelopmentofkeycomplementarytechnologies;especiallythosethatallowedhigherfrequenciestobeutilisedmoreefficiently.Finally,becauseofitsspecialnature,theefficientuseofspectrumrequiredthecoordinateddevelopmentofstandards.Thosestandardsinturnplayedacriticalroleinthediffusionoftechnologiesthatreliedonspectrumuse.Inlargepartourchapterfocusesonwirelesstelephonyratherthanbroadcastingandotherusesofspectrum(e.g.,telemetryandbiomedicalservices).Specifically,theeconomicsliteratureonthatindustryhasfocusedonfactorsdrivingthediffusionofwirelesstelecommunicationtechnologiesandonthenatureofnetworkpricingregulationandcompetitionintheindustry.Byfocusingontheeconomicliterature,thischaptercomplementsothersurveysinthisHandbook.Hausman(2002)focusesontechnologicalandpolicydevelopmentsinmobiletelephonyratherthaneconomicresearchperse.Cramton(2002)providesasurveyofthetheoryandpracticeofspectrumauctionsusedforprivatisation.Armstrong(2002a)andNoam(2002)considergeneralissuesregardingnetworkinterconnectionandaccesspricingwhileWoroch(2002)investigatesthepotentialforwirelesstechnologiesasasubstituteforlocalfixedlinetelephony.Finally,LiebowitzandMargolis(2002)provideageneralsurveyoftheeconomicsliteratureonnetworkeffects.Incontrast,wefocusheresolelyontheeconomicliteratureonthemobiletelephonyindustry.Theoutlineforthischapterisasfollows.Thenextsectionprovidesbackgroundinformationregardingtheadoptionofwirelesscommunicationtechnologies.Section3thenconsiderstheeconomicissuesassociatedwithmobiletelephonyincludingspectrumallocationandstandards.Section4surveysrecenteconomicstudiesofthediffusionofmobiletelephony.Finally,section5reviewsissuesofregulationandcompetition;inparticular,theneedforandprinciplesbehindaccesspricingformobilephonenetworks.2.BackgroundMarconi’spioneeringworkquicklyledtovarietyofcommercialandgovernment(particularlymilitary)developmentsandinnovations.Intheearly1900s,voiceandthenmusicwastransmittedandmodernradiowasborn.By1920,commercialradiohadbeenestablishedwithDetroitstationWWJandKDKAinPittsburgh.WirelesstelegraphywasfirstusedbytheBritishmilitaryinSouthAfricain1900duringtheAnglo-Boerwar.TheBritishnavyusedequipmentsuppliedbyMarconitocommunicatebetweenshipsinDelagoaBay.ShippingwasamajorearlyclientforwirelesstelegraphyandwirelesswasstandardforshippingbythetimetheTitanicissueditsradiodistresscallsin1912.1Earlyon,itwasquicklyrecognizedthatinternationalcoordinationwasrequiredforwirelesscommunicationtobeeffective.Thiscoordinationinvolvedtwofeatures.First,thepotentialforinterferenceinradiotransmissionsmeantthatatleastlocalcoordinationwasneededtoavoidthetransmissionofconflictingsignals.Secondly,withspectrumtobeusedforinternationalcommunicationsandareassuchasmaritimesafetyandnavigation,coordinationwasnecessarybetweencountriestoguaranteeconsistencyinapproachtotheseservices.Thisdrovegovernmentinterventiontoensurethecoordinatedallocationofradiospectrum.2.1SpectrumAllocationRadiotransmissioninvolvestheuseofpartoftheelectromagneticspectrum.Electromagneticenergyistransmittedindifferentfrequenciesandthepropertiesoftheenergydependonthefrequency.Forexample,visiblelighthasafrequencybetween4×1014and7.5×1014Hz.2Ultravioletradiation,X-raysandgammarayshavehigherfrequencies(orequivalentlyashorterwavelength)whileinfraredradiation,microwavesandradiowaveshavelowerfrequencies(longerwavelengths).Theradiofrequencyspectruminvolveselectromagneticradiationwithfrequenciesbetween3000Hzand300GHz.3Evenwithintheradiospectrum,differentfrequencieshavedifferentproperties.AsCave(2001)notes,thehigherthefrequency,theshorterthedistancethesignalwilltravel,butthegreaterthecapacityofthesignaltocarrydata.Thetasksofinternationallycoordinatingtheuseofradiospectrum,managinginterferenceandsettingglobalstandardsareundertakenbytheInternationalTelecommunicationUnion(ITU).TheITUwascreatedbytheInternationalTelecommunicationsConventionin1947buthaspredecessorsdatingbacktoapproximately1865.4ItisaspecialistagencyoftheUnitedNationswithover180members.TheRadiocommunicationSectoroftheITUcoordinatesglobalspectrumusethroughtheRadioRegulations.Theseregulationswerefirstputinplaceatthe1906BerlinInternationalRadiotelegraphConference.Allocationoftheradiospectrumoccursalongthreedimensions–thefrequency,thegeographiclocationandthepriorityoftheuserwithregardstointerference.Theradiospectrumisbrokenintoeightfrequencybands,rangingfromVeryLowFrequency(3to30kHz)uptoExtremelyHighFrequency(30to300GHz).Geographically,theworldisalsodividedintothreeregions.TheITUthenallocatescertainfrequenciesforspecificusesoneitheraworldwideoraregionalbasis.IndividualcountriesmaythenfurtherallocatefrequencieswithintheITUinternationalallocation.Forexample,intheUnitedStates,theFederalCommunicationsCommission’s(FCC’s)tableoffrequencyallocationsisderivedfromboththeinternationaltableofallocationsandU.S.allocations.Usersarebrokenintoprimaryandsecondaryservices,withprimaryusersprotectedfrominterferencefromsecondaryusersbutnotviceversa.Asanexample,in2003,thebandbelow9kHzwasnotallocatedintheinternationalortheU.S.table.9to14kHzwasallocatedtoradionavigationinbothtablesandallinternationalregionswhile14to70kHzisallocatedwithbothmaritimecommunicationsandfixedwirelesscommunicationsasprimaryusers.Thereisalsoaninternationaltimesignalat20kHz.ButtheU.S.tablealsoaddsanadditionaltimefrequencyat60kHz.Internationalregionaldistinctionsbegintoappearinthe70to90kHzrangewithdifferencesinuseandprioritybetweenradionavigation,fixed,radiolocationandmaritimemobileuses.Theseallocationscontinuerightupto300GHz,withfrequenciesabove300GHznotallocatedintheUnitedStatesandthoseabove275GHznotallocatedintheinternationaltable.5TheITUdealswithinterferencebyrequiringmembercountriestofollownotificationandregistrationprocedureswhenevertheyplantoassignfrequencytoaparticularuse,suchasaradiostationoranewsatellite.2.2TherangeofwirelessservicesRadiospectrumisusedforawiderangeofservices.Thesecanbebrokenintothefollowingbroadclasses:?Broadcastingservices:includingshortwave,AMandFMradioaswellasterrestrialtelevision;?Mobilecommunicationsofvoiceanddata:includingmaritimeandaeronauticalmobileforcommunicationsbetweenships,airplanesandland;landmobileforcommunicationsbetweenafixedbasestationandmovingsitessuchasataxifleetandpagingservices,andmobilecommunicationseitherbetweenmobileusersandafixednetworkorbetweenmobileusers,suchasmobiletelephoneservices;?FixedServices:eitherpointtopointorpointtomultipointservices;?Satellite:usedforbroadcasting,telecommunicationsandinternet,particularlyoverlongdistances;?Amateurradio;?OtherUses:includingmilitary,radioastronomy,meteorologicalandscientificuses.6Theamountofspectrumallocatedtothesedifferentusesdiffersbycountryandfrequencyband.Forexample,intheU.K.,40%ofthe88MHzto1GHzbandoffrequenciesareusedforTVbroadcasting,22%fordefense,10%forGSMmobileand1%formaritimecommunications.Incontrast,noneofthe1GHzto3GHzfrequencyrangeisusedfortelevision,19%isallocatedtoGSMandthird-generationmobilephones,17%todefenseand23%foraeronauticalradar.7Thenumberofdifferentdevicesusingwirelesscommunicationsisrisingrapidly.Sensorsandembeddedwirelesscontrollersareincreasinglyusedinavarietyofappliancesandapplications.Personaldigitalassistants(PDAs)andmobilecomputersareregularlyconnectedtoe-mailandinternetservicesthroughwirelesscommunications,andwirelesslocalareanetworksforcomputersarebecomingcommoninpublicareaslikeairportlounges.However,byfarthemostimportantanddramaticchangeintheuseofwirelesscommunicationsinthepasttwentyyearshasbeentheriseofthemobiletelephone.2.3TheriseandriseofmobiletelephonyThehistoryofmobiletelephonescanbebrokenintofourperiods.Thefirst(pre-cellular)periodinvolvedmobiletelephonesthatexclusivelyusedafrequencybandinaparticulararea.Thesetelephoneshadsevereproblemswithcongestionandcallcompletion.Ifonecustomerwasusingaparticularfrequencyinageographicarea,noothercustomercouldmakeacallonthatsamefrequency.Further,thenumberoffrequenciesallocatedbytheFCCintheU.S.tomobiletelephoneserviceswassmall,limitingthenumberofsimultaneouscalls.Similarsystems,knownasA-NetzandB-NetzweredevelopedinGermany.Theintroductionofcellulartechnologygreatlyexpandedtheefficiencyoffrequencyuseofmobilephones.Ratherthanexclusivelyallocatingabandoffrequencytoonetelephonecallinalargegeographicarea,acelltelephonebreaksdownageographicareaintosmallareasorcells.Differentusersindifferent(non-adjacent)cellsareabletousethesamefrequencyforacallwithoutinterference.Firstgenerationcellularmobiletelephonesdevelopedaroundtheworldusingdifferent,incompatibleanaloguetechnologies.Forexample,inthe1980sintheU.S.therewastheAdvancedMobilePhoneSystem(AMPS),theU.K.hadtheTotalAccessCommunicationsSystem(TACS),GermanydevelopedC-Netz,whileScandinaviadevelopedtheNordicMobileTelephone(NMT)system.Theresultwasawiderangeoflargelyincompatiblesystems,particularlyinEurope,althoughthesingleAMPSsystemwasusedthroughouttheU.S.Secondgeneration(2G)mobiletelephonesuseddigitaltechnology.TheadoptionofsecondgenerationtechnologydifferedsubstantiallybetweentheUnitedStatesandEuropeandreversestheearlieranaloguemobileexperience.InEurope,acommonstandardwasadopted,partlyduetogovernmentintervention.GroupeSpecialeMobile(GSM)wasfirstdevelopedinthe1980sandwasthefirst2Gsystem.Butitwasonlyin1990thatGSMwasstandardized(withthenewnameofGlobalSystemforMobilecommunication)undertheauspicesoftheEuropeanTechnicalStandardsInstitute.ThestandardizedGSMcouldallowfullinternationalroaming,automaticlocationservices,commonencryptionandrelativelyhighqualityaudio.GSMisnowthemostwidelyused2Gsystemworldwide,inmorethan130countries,usingthe900MHzfrequencyrange.Incontrast,avarietyofincompatible2GstandardsdevelopedintheUnitedStates.TheseincludeTDMA,acloserelativeofGSM,andCDMA,referringtoTimeandCodeDivisionMultipleAccessrespectively.Thesetechnologiesdifferinhowtheybreakdowncallstoallowformoreefficientuseofspectrumwithinasinglecell.Whilethereissomeargumentastothe‘better’system,thefailureoftheU.S.toadoptacommon2Gstandard,withtheassociatedbenefitsintermsofroamingandswitchingofhandsets,meantthefirstgenerationAMPSsystemremainedthemostpopularmobiletechnologyintheU.S.throughoutthe1990s.Thefinalstageinthedevelopmentofmobiletelephonesisthemovetothirdgeneration(3G)technology.Thesesystemswillallowforsignificantlyincreasedspeedsoftransmissionandareparticularlyusefulfordataservices.Forexample,3Gphonescanmoreefficientlybeusedfore-mailservices,anddownloadingcontent(suchasmusicandvideos)fromtheinternet.Theycanalsoallowmorerapidtransmissionofimages,forexamplefromcameraphones.Anattempttoestablishaninternationalstandardfor3GmobileisbeingmoderatedthroughtheITU,undertheauspicesofitsIMT-2000program.IMT-2000determinedthat3GtechnologyshouldbebasedonCDMAsystemsbutthereare(atleasttwo)alternativecompetingsystemsandIMT-2000didnotchooseasinglesystembutratherasuiteofapproaches.AttheITU’sWorldRadiocommunicationConferencein2000,frequenciesforIMT-2000systemswereallocatedonaworldwidebasis.By2002,theonly3GsysteminoperationwasinJapan,althoughnumerouscompanieshaveplanstorollout3Gsystemsinthenextfewyears.Thegrowthinuseofmobiletelephoneshasbeenspectacular.Fromalmostazerobaseintheearly1980s,mobilepenetrationworldwidein2002isestimatedat15.57mobilephonesper100peopleworldwide.Ofcourse,thelevelofpenetrationdiffersgreatlybetweencountries.IntheUnitedStates,therewere44.2mobiletelephonesper100inhabitants,withpenetrationratesof60.53inFrance,68.29inGermany,77.84inFinlandand78.28intheUnitedKingdom.Thus,ingeneralmobilepenetrationislowerintheU.S.thaninthewealthierEuropeancountries.OutsideEuropeandtheU.S.,thepenetrationrateinAustraliais57.75,62.13inNewZealand,and58.76inJapan.Unsurprisingly,penetrationratesdependonthelevelofeconomicdevelopment,sothatIndiahadonly0.63mobiletelephonesper100inhabitantsin2002,with1.60forKenya,11.17forChina,and29.95forMalaysia.Thenumberofmobilephonesnowexceedsthenumberoffixed-wiretelephonelinesinavarietyofcountriesincludingGermany,France,theUnitedKingdom,Greece,ItalyandBelgium.However,thereverseholds,withfixed-linesoutnumberingmobilesintheUnitedStates,Canada,andArgentina.PenetrationrateswereclosetoequalinJapanin2001,butinallcountries,mobilepenetrationisrisingmuchfasterthanfixedlines.8Thepriceformobilephoneservicesaredifficulttocomparebetweencountries.Inpartthisreflectsexchangeratevariations,butmoreimportantlypricingpackagesandtheformofpricingdifferssignificantlybetweencountries.Mostobviously,differentcountrieshavedifferentchargingmechanisms,with‘callingpartypays’dominatingoutsidetheUnitedStates.ButintheUnitedStatesandCanada‘receivingpartypays’pricingoftenappliesforcallstomobiletelephones.Differentpackagesandbundlingofequipmentandcallchargesalsomakecomparisonsdifficult.Amajorinnovationinmobiletelephonepricinginthelate1990swastheuseofpre-paidcards.Thissystem,wherecustomerspayinadvanceformobilecallsratherthanbeingbilledatalaterdate,hasprovedpopularinmanycountries.Forexample,inSweden,pre-paidcardsgained25%ofthemobilemarketwithintwoyearsoftheirintroduction(OECD,2000,p.11).Despitethechangingpatternsofpricing,theOECDestimatesthattherewasa25%fallinthecostofarepresentative‘bundle’ofmobileservicesoveritsmembercountriesbetween1992and1998(OECD,2000,p.22).3.EconomicIssuesinWirelessCommunications3.1SpectrumasascarceresourceRadiospectrumisanaturalresource,butonewithratherunusualproperties.Asnotedabove,itisnon-homogeneous,withdifferentpartsofthespectrumbeingbestusedfordifferentpurposes.Itisfiniteinthesensethatonlypartoftheelectromagneticspectrumissuitableforwirelesscommunications,althoughboththeavailablefrequenciesandthecarryingcapacityofanytransmissionsystemdependontechnology.Theradiospectrumisnon-depletable;usingspectrumtodaydoesnotreducetheamountavailableforuseinthefuture.Butitisnon-storable.UnderITUguidance,spectrumhasbeenallocatedtospecificusesandthenassignedtoparticularusersgiventherelevantuse.Traditionally,userassignmentwasbygovernmentfiat.Notinfrequently,theuserwasgovernmentowned.Privatizationsinthe1980sand1990s,andthesuccessof(atleastlimited)mobiletelephonecompetitioninsomecountries,resultedinamorearms-lengthprocessofspectrumallocationdevelopinginthe1990s.Usersofradiospectrum,andparticularlyusersof2Gand3Gmobiletelephonespectrum,havegenerallybeenchosenbyoneoftwobroadapproachessincetheearly1990s–a‘beautycontest’oranauction.A‘beautycontest’involvespotentialuserssubmittingbusinessplanstothegovernment(oritsappointedcommittee).Thewinnersarethenchosenfromthosefirmssubmittingplans.Theremaybesomepaymenttothegovernmentbythewinners,althoughthepotentialusermostwillingtopayforthespectrumneednotbeamongthewinners.Forexample,theU.K.usedabeautycontestapproachtoassign2Gmobiletelephonelicensesinthe1990s.SwedenandSpainhaveusedbeautyconteststoassign3Glicenses.Franceusedabeautycontesttoassignfour3Glicenses.ThenationaltelecommunicationsregulatorrequiredfirmstosubmitapplicationsbytheendofJanuary2001.Theseapplicationswerethenevaluatedaccordingtopresetcriteriaandgivenamarkoutof500.Criteriaincludedemployment(worthupto25points),serviceofferings(upto50points)andspeedofdeployment(upto100points).Winningapplicantsfacedarelativelyhighlicensefeesetbythegovernment.Asaresult,therewereonlytwoapplicants.ThesefirmsreceivedtheirlicensesinJune2001,withtheremainingtwolicensesunallocated(Penard,2002).Theconceptofusingamarketmechanismtoassignpropertyrightsoverspectrumandtodealwithissuessuchasinterferencegoesbacktoatleastthe1950swhenitwascanvassedbyHerzel(1951)andthenbyCoase(1959).Butitwasmorethanthirtyyearsbeforespectrumauctionsbecamecommon.NewZealandaltereditslawstoallowspectrumauctionsin1989andintheearly1990sauctionswereusedtoassignblocksofspectrumrelatingtomobiletelephones,television,radiobroadcastingandothersmallerservicestoprivatemanagement(Crandall,1998).InAugust1993,U.S.lawwasmodifiedtoallowtheFCCtouseauctionstoassignradiospectrumlicensesandbyJuly1996theFCChadconductedsevenauctionsandassignedover2,100licenses(MoretonandSpiller,1998).Thisincludedtheassignmentoftwonew2GmobiletelephonelicensesineachregionoftheU.S.throughtwoauctions.9In2000,theU.K.auctionedofffive3GAuctionshaveinvolvedavarietyofformatsincluding‘secondpricesealedbid’inNewZealand,modifiedascendingbidintheU.S.andamixedascendingbidandDutchauctionformatintheU.K.11Biddersmayhavetosatisfycertaincriteria,suchasserviceguaranteesandparticipationdeposits,beforetheycanparticipateintheauctions.Limitsmayalsobeplacedonthenumberoflicensesasinglefirmcanwininaparticulargeographicarea,sothattheauctiondoesnotcreateamonopolysupplier.Fromaneconomicperspective,usinganauctiontoassignspectrumhelpsensurethatthespectrumgoestothehighestvalueuser.Whileauctionshavebeenusedtoassignspectrumtodifferentusers,theystillinvolveapriorcentralizedallocationofbandsofspectrumtoparticularuses.Economically,thiscanleadtoaninefficientuseofspectrum.Auserofaparticularfrequencyband(e.g.for3Gservices)mighthaveamuchhigherwillingness-to-payforneighboringspectrumthanthecurrentuserofthatneighboringspectrum(e.g.abroadcasterorthemilitary).Butthepriorallocationoffrequencybandsmeansthatthesepartiesareunabletobenefitfrommutuallyadvantageoustrade.Itwouldviolatetheexistinglicenseconditionstomovespectrumallocatedtooneuseintoanotheruseevenifthisismutuallyadvantageous.BuildingontheworkofCoase(1959),Valletti(2001)proposesasystemoftradablespectrumrights,usingthemarkettobothallocatespectrumtousesandsimultaneouslyassignittousers.Interferencecanbedealtwiththroughtheassignmentofpropertyrightsandnegotiationbetweenownersofneighboringspectrum.Vallettinotesthatbothcompetitionissuesandissuesofmandatedstandardswouldneedtobeaddressedinamarketforspectrumrights.Wedealwiththeissueofstandardslaterinthissectionwhilecompetitionissuesareconsideredinsection5below.Noam(1997)takestheconceptoftradablespectrumassignmentonestagefurther.Technologicaladvancements,suchastheabilityforasignaltobebrokenintonumerousseparatedigitalpacketsforthepurposesoftransmissionandthenreassembledonreception,meansthattheconceptofpermanentspectrumassignmentmaybecomeredundantinthenearfuture.Astechnologyadvances,Noamargues,spotandforwardmarketscanbeusedtoassignusewithindesignatedbandsofspectrum.Thepriceofspectrumusewouldthenaltertoreflectcongestionofuse.DeVany(1998)alsodiscussesmarket-basedspectrumpolicies,includingthepotentialforafuture“open,commoditized,unbundledspectrummarketsystem.”(p.641)ConflictsintheallocationofspectrumallocationaroseintheFCCauctionsintheU.S.The1850-1910MHzand1930-1990MHzbandstobeallocatedbytheseauctionsalreadyhadprivatefixedpoint-to-pointusers.TheFCCruledthatexistingusershadaperiodofuptothreeyearstonegotiatealternativespectrumlocationandcompensationwithnewusers.Ifnegotiationsfailed,theexistingusercouldbeinvoluntarilyrelocated.Cramton,KwerelandWilliams(1998)examineavarietyofalternative‘propertyrights’regimesfornegotiatedreallocationofexistingspectrumandconcludethattheexperienceoftheU.S.reallocationsisroughlyconsistentwithsimplebargainingtheory.Whileeconomistshavegenerallyadvocatedtheassignmentofspectrumbyauction,auctionsarenotwithouttheircritics.BinmoreandKlemperer(2002)arguethatanumberoftheargumentsagainstauctionsaremisguided.ButbothNoam(1997)andGruber(2001b)makethecriticismthatspectrumauctionsautomaticallycreateanon-competitiveoligopolyenvironment.Gruberarguesthattechnologicalchangehasgenerallyincreasedtheefficiencyofspectrumuseandincreasedtheviabilityofcompetitioninwirelessservices.Forexample,intermsofspectralefficiency,GSMmobiletelephoneservicesareapproximatelyfourtothirtytimesmoreefficientthanearlieranaloguesystems(Gruber,2001b,Table1).Anauctionofspectrumrights,however,isprecededbyanallocationofspectrum.Thegovernmentusuallyallocatesafixedbandofspectrumtotherelevantservices.Further,thegovernmentusuallydecidesonthenumberoflicensesthatitwillauctionwithinthisband.Sothepricepaidattheauctionandthelevelofexpostcompetitionintherelevantwirelessservicesaredeterminedbytheamountofspectrumandthenumberoflicensesthegovernmentinitiallyallocatestotheservice.Whiletheauctioncreatescompetitionforthescarcespectrum,itdoesnotallowthemarkettodeterminetheoptimalformofcompetition.Noamarguesthatflexibilityofentryneedstobeprovidedbytheassignmentsysteminordertoovercometheartificialcreationofanon-competitivemarketstructure.3.2ComplementaritiesinspectrumuseUsingspectrumtoproducewirelesscommunicationsservicescanleadtosynergiesbetweenservicesandbetweengeographicregions.IntheU.K.,3Gspectrumauction,thepotentialsynergiesbetween2Gand3GmobiletelephoneinfrastructurewasnotedbyBinmoreandKlemperer:[T]heincumbentswhoarealreadyoperatinginthe2Gtelecomindustryenjoyamajoradvantageoverpotentialnewentrants….Notonlyaretheincumbents’2Gbusinessescomplementaryto3G,butthecostsofrollingouttheinfrastructure(radiomastsandthelike)necessarytooperatea3Gindustryareverysubstantiallylessthanthoseofanewentrant,becausetheycanpiggybackonthe2Ginfrastructure.(2002,p.C80)Thus,therearesynergiesintermsofbeingabletosupplynewproductstoanexistingcustomerbaseusingexistingbrands,andeconomiesofscopebetween2Gand3Gservices.GeographicsynergiesareevidentfromtheFCC2Gauctions.MoretonandSpiller(1998)examinethetwo1995-96mobilephoneauctionsintheU.S.Theyrunareduced-formregressiononthewinningbidforeachlicenseandanumberoffactorsd