理论研究通用分组无线业务-外文翻译

《理论研究通用分组无线业务-外文翻译》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。

1、TheoreticalStudyoftheGeneralPacketRadioServiceAbstract:Ascommunicationstechnologycontinuestomaturea-ndusers'qualityhavebecomeincreasinglydemanding,newda-taapplicationsareemergingandarereachingthegeneralpublic.ThroughtheuseofGPRS(GeneralPacketRadioService)techn-ology,theexistingGSMnetworkscanbeeasil

2、yachievedwithsimplehigh-speeddatapacketaccess,enablingmobileoperatorstorespondrapidlytomarketdemandsandgaincompetitiveadva-ntage.ThispaperaimstoprovideacomprehensiveyetsimpleoverviewoftheGPRSsystemfromtheuser'sandfromthearch-itecturalperspectives.Keywords:GPRSnetworks;Voice/dataintegration;Multiple

3、-channels;Packetradio;Telecommunications1IntroductionInthelate1800s,Marconididthepioneerworkestablishingthefirstsuccessfulradiolinkbetweenaland-basedstationandatugboat.Sincethen,wirelesscommunicationsystemshavebeendevelopingandevolvingwithafuriouspace・Thenumberofmobilesubscribershasbeengrowingtreme

4、ndouslyinthepastdecades.Intheearlystages,wirelesscommunicationsystemsweredominatedbymilitaryusageandsupportedaccordingtomilitaryneedsandrequirements・Duringthelasthalfacentury,withincreasingcivilapplicationsofmobileservices,commercialwirelesscommunicationsystemshavebeentakingthelead・Theearlywireless

5、systemsconsistedofabasestationwithahigh-powertransmitterandservedalargegeographicarea.Eachbasestationcouldserveonlyasmallnumberofusersandwascostlyaswell.ThesystemswereisolatedfromeachotherandonlyafewofthecommunicatedwiththePSTNs(PublicSwitchedTelephoneNetworks).Today,thecellularsystemsconsistofaclu

6、sterofba-sestationwithlowpowerradiotransmitters.Eachbasestations-ervesasmallcellwithinalargegeographicarea.Thetotalnum・herofusersservedisincreasedbecauseofchannelreuseandal-solargerfrequencybandwidth.GlobalsystemformobilecommunicationsistheEuropeanstandardforcellularcommunicationsdevelopedbytheETSI

7、(EuropeanTelecommunicationsStandardsInstitute).ThroughoutEuropeandtherestoftheworld,GSMhasbeenwidelyadopted.lthasalreadybeenimplementedinover100countries.ThemostimportantserviceinGSMisvoicetelephony.Voiceis