电信行业--3G行动通讯与VoIP网际电话之企业应用与发展(PPT 32页).ppt

3G行動通訊與VoIP網際電話之企業應用與發展,Content,IntroductiontoTelecommunications3GLicensesAuctionUMTSWCDMAWirelessApplicationsVoIP21102125MHz)+5MHz(19151920MHz)執照B：2x10MHz(19351945MHz;21252135MHz)+5MHz(20102015MHz)執照C：2x15MHz(19451960MHz;21352150MHz)+5MHz(20152020MHz)執照D：2x15MHz(19601975MHz;21502165MHz)+5MHz(20202025MHz)執照E：2x20MHz(825845MHz;870890MHz),3G拍賣趨勢,1Q20002Q20003Q20004Q20001H20012H2001,Liechtenstein,Spain,UK,Japan,Netherlands,Germany,Italy,Austria,Norway,Switzerland,Sweden,Portugal,Finland,France,5xWCDMA,6xWCDMA,2xWCDMA1xCDMA2000,1xWCDMA,4xWCDMA,4xWCDMA,5xWCDMA,5xWCDMA,4xWCDMA,4xWCDMA,4xWCDMA,6xWCDMA,S.Korea,5xWCDMA,2xWCDMA1xCDMA2000,Denmark,Greece,Ireland,HongKong,Taiwan,Czech,Belgium,3xWCDMA,73WCDMAlicencesawardedplusmoretocome(120byend2001)Vs13CDMA2000networksplanned(outofwhich2alreadyoptedforWCDMA),Australia,NewZealand,Singapore,4xWCDMA,4xWCDMA,5xWCDMA,GPRSNetwork,115kbpsusing8timeslotsSGSN:ServingGPRSSupportNode,3GNetwork,384kbps2Mbps,Mobilemultimediastreaming,PDAhandset,FDD:frequencydivisionduplex,Uplinkanddownlinkfrequenciesaredifferenceandaenoughfrequencyspacingmustbeexist.,17101785MHz,18051880MHz,TDD:timedivisionduplex,Uplinkanddownlinkusethesamefrequency,buttransmitsignalsatdifferenttime.,18951918MHz,18951918MHz,FDMA:frequencydivisionmultipleaccess,Usersusedifferentfrequencycarriers200kHz/channelforGSM,Channel#1,Channel#2,TDMA:timedivisionmultipleaccess,Eachcarriercancontainmanyusers,buttheyusethesamecarrieratdifferenttimeslots.,channel#1timeslot#1,channel#1timeslot#2,TDMA/TDD,PHSfromJapanCarrierspacingis300kHz,Uplink,downlink,time,Cch,Cch,TDMA/FDD,GSMCarrierspacingis200kHzEachcarriercontains8users,uplinkfrequency,downlinkfrequency,CDMA:codedivisionmultipleaccess,WirelessApplications,Person-to-person(communications)servicesMobileE-commerceservices:video1and2Travel/locationbasedservicesRemotediagnosticsTelemetryservicesMobileoffice(business)servicesEntertainment/leisureservices:video1and2,Conclusions,3Gwillprovidewiderangeofvoiceandnon-voiceserviceincludingcircuit/packetswitchingandmultimediaservice.Itispossiblefor3Gtocreatenewapplicationsinacost-effectivemanner.MobileandtheInternetwillbethemajordemanddriversforthefuture,VoIP網際網路電,Skype官方網站:,VoIP,網友評論:*最近很紅的一個對談軟體Skype(繁體中文語言包)用了P2P技術,過防火牆後還是超級清楚,美東與台灣連線時對方說話就像坐在正對面一樣,讓我徹底對網路語音軟體改觀,想想以前用yahoomessenger或MSN那種模糊延遲的語音真是好笑.然後因為它免費又太清楚,介紹親友後我已經很久沒花錢打國際電話了.*清晰度一級棒，即時通和MSN根本無法比啊！並且即時通和MSN都只能單向發話，而SKYPE完全跟電話一模一樣！目前試用過：台灣台灣、大陸、加拿大、東京超清晰，完全沒有延遲的狀況！使用藍芽耳機，爽度更是百分之兩百啊*我有一