Unit203GTextKeywordsTechnicaltermsExpressionsNotestothetextText

Witheachgenerationoftechnology,theserviceswhichcandeployedonthembecomesmoreandmorewiderangingandtrulylimitedonlybyimagination.Thenextgenerationofbroadbandwirelesscommunication,basedonThirdGenerationor“3G”technology,willchangeourlivesforever.Whatis3G?

Themobilecommunicationsindustryhasevolvedinthreestages:analogue,digitalandmultimedia.Threegenerationsofmobilephoneshaveemergedsofar,eachsuccessivegenerationmorereliableandflexiblethanthelast:Youcouldonlyeasilyuseanaloguecellulartomakevoicecalls,andtypicallyonlyinanyonecountry.Digitalmobilephonesystemsaddedfax,dataandmessagingcapabilitiesaswellasvoicetelephoneserviceinmanycountries.Multimediaservicesaddhighspeeddatatransfertomobiledevices,allowingnewvideo,audioandotherapplicationsthroughmobilephones—allowingmusicandtelevisionandtheInternettobeaccessedthroughamobileterminal.TheThirdGeneration(3G)isthemobilemultimediabasedonCDMAtechnology.

Anewradiocommunicationstechnologythatwillprovidehigh-speedmobileaccesstoInternet-basedservices.Itwillenhanceandextendmobilityinmanyareasofourlives.We’llexpecthigh-speedaccesstotheInternet,entertainment,informationandelectroniccommerce(e-commerce)serviceswhereverweare—notjustatourdesktopcomputers,homePCsortelevisionsets.

Ina3Gworld,userswon’talwaysneedto“dialup”toretrieveemail,multimediaattachmentsandotherdata.Itwillsimplybedownloadedtotheirmobiledevicesassoonasitissentorrequested.

Theshiftto3GservicesisalsocausingarevolutionintheunderlyingtelecommunicationssystemasphonecompaniesembracetheInternetandfurtherintegratewirelessandtraditionalfixed-wirenetworks.Thiswillchangethewaywethinkabouttelecommunication.

3GFeatures

3Ghasthefollowingfeatures:

Packeteverywhere

WithThirdGeneration(3G),theinformationissplitintoseparatebutrelatedpacketsbeforebeingtransmittedandreassembledatthereceivingend.Packetswitchingissimilartoajigsawpuzzle—theimagethatthepuzzlerepresentsisdividedintopiecesatthemanufacturingfactoryandputintoaplasticbag.Duringtransportationofthenowboxedjigsawfromthefactorytotheenduser,thepiecesgetjumbledup.Whentherecipientemptiesthebagwithallthepieces,theyarereassembledtoformtheoriginalimage.Allthepiecesareallrelatedandfittogether,butthewaytheyaretransportedandassembledvaries.

Packetswitcheddataformatsaremuchmorecommonthantheircircuitswitchedcounterparts.Otherexamplesofpacket-baseddatastandardsincludeTCP/IP,X.25,FrameRelayandAsynchronousTransferMode(ATM).Inthemobileworld,CDPD(cellularDigitalPacketData),PDCP(PersonalDigitalCellularPacket),GeneralPacketRadioService(GPRS)andwirelessX.25technologieshavebeeninoperationforseveralyears.X.25istheinternationalpublicaccesspacketradiodatanetworkstandard.

InternetEverywhere

TheWorldWideWebisbecomingtheprimarycommunicationsinterface—peopleaccessInternetforentertainmentandinformationcollection,theintranetforaccessingcompanyinformationandconnectingwithcolleaguesandtheextranetforaccessingcustomersandsuppliers.TheseareallderivativesoftheWorldWideWebaimedatconnectingdifferentcommunitiesofinterest.ThereisatrendawayfromstoringinformationlocallyinspecificsoftwarepackagesonPCstoremotelyontheinternet.Webbrowsingisaveryimportantapplicationforpacketdata.

HighSpeed

Speedsofupto2Megabitspersecond(Mbps)areachievablewithThirdGeneration(3G).Thedatatransmissionrateswilldependupontheenvironmentthecallisbeingmadein—itisonlyindoorsandinstationaryenvironmentsthatthesetypesofdatarateswillbeavailable.Forhighmobility,dataratesof144kbpsareexpectedtobeavailable—thisisonlyaboutthreetimesthespeedoftodayfixedtelecomsmodems.

NewApplications,BetterApplications

ThirdGeneration(3G)facilitatesseveralnewapplicationsthathavenotpreviouslybeenreadilyavailableovermobilenetworksduetothelimitationsindatatransmissionspeeds.TheseapplicationsrangefromWebBrowsingtofiletransfertoHomeAutomation—theabilitytoremotelyaccessandcontrolinhouseappliancesandmachines.Becauseofthebandwidthincrease,theseapplicationswillbeevenmoreeasilyavailablewith3GthantheywerepreviouslywithinterimtechnologiessuchasGPRS.

3Gwillmeanmanythingstomanypeople.Butmostofallitwillbeaboutspeed,intelligence,convenienceandhavingtheInternetatyourfingertips—allthetime.Sogetreadyforanewworldofspeed,knowledgeandconvenience.Getreadyfor3G.Keywords

generation n.產(chǎn)生，一代

deploy v.展開，配置

fax n.vt.傳真

mobility n.活動(dòng)性，靈活性，遷移率，機(jī)動(dòng)性

desktop n.?[計(jì)]桌面；臺(tái)式電腦

retrieve v.重新得到

attachment n.附件，附加裝置，配屬

download v.下載

telecommunication n.電信，電信學(xué)

reassemble vt.重新召集；vi.重新集合

jumble v.混雜，搞亂；n.混亂

protocol n.草案，協(xié)議

intranet n.內(nèi)聯(lián)網(wǎng)，企業(yè)內(nèi)部互聯(lián)網(wǎng)

interim adj.過渡的，臨時(shí)的Technicalterms

ThirdGenerationor“3G”technology 第三代(或“3G”)技術(shù)

CDMA(CodeDivisionMultipleAddress) 碼分多址

packetswitching 分組交換

TCP(TransferControlProtocol) 傳輸控制協(xié)議

IP(InternetProtocol) 網(wǎng)際協(xié)議

FrameRelay [計(jì)]幀中繼

ATM(AsynchronousTransferMode) 異步傳輸模式

CDPD(cellularDigitalPacketData) 蜂窩數(shù)字分組數(shù)據(jù)

PDCP(PersonalDigitalCellularPacket) 個(gè)人數(shù)字蜂窩分組

GPRS(GeneralPacketRadioService) 通用分組無線業(yè)務(wù)

WorldWi