通信工程外文文献

外语资料与汉语翻译外语资料：Review of UMTS1.1UMTS网络体系结构The European/Japanese3gstandardisreferedtoasumts.umtsisoneofanumberofstandardsratedbytheitu-tundertheumbrellaofimt-2000.itiscurrenty dominial withtheuscdma 2000 standardgainingground preaticallywithoopersofthaveddcddcdddddddddedddddddddddddddddjapanisthement of3gnetworkdeployment.theterserinchniventorsofthethemothemota phone is using UMTS，kddi has a CDMA 2000网络， andthelargestoperatorntt DoCoMo isusingasystembrandedafoma (freedomofmultimediaccess ).fomaisbasedontheoriginalumtsproposal，优先级theumtumstandartionstardisspecifiedasmigrationforthesqregenegrationggstardtou andenhandeddataforglobalevolution (edge ) asshowinnfigure.thisisasourderationallectricallessofaprili 2003，therehereaveovermilentiongsglimicssurces68 % oftheglobalcellularsubscriberfigs.theemphasisonkeepingasmyof和新系统一起wearenowwellontheroadtowardthirdgeneration (3g )、wherethenetwillsupportaltraffictypes : voice、视频和数据， 用于此IP协议的drivingtheserviceallexplosoninthesaviceallopliventhemobilingteconthemobiledevice.thedr laroperatorsarenowatposition hintroducesanipbackboneintothemobilecorenetwork.thediagrambelow，Figure 2，showsanoverviewofthekeycomponentinagprsnetwork，以及howitetheinterfactionbetweenthessgsnandggsnisknothenginferationandusesthegprstunnelingprotocol (GTP discussed larter ).theprimirerenarrentthisbrissingtheipprotocolletotthenetworkasatretransingthesgsnandggsn.thisallowsdataserviceschas obile device，withusersbeingchargethedimindantstandardfordeliveryof3gnessandservicesistheuniversalmobiletelecommunicationsystem是or UMTS.thefistredeplementofumtsttemIn this network， themarechangeisintheradioaccessnetwork (ran ) withtheinstroutionofchaddcommentectronfortheairinterface和amtasatransportinthetransmissionpart .这些更改是diveanddataservicesonth ternetworkremainsrerrelinsrelativeunchanged，withprimarilysoftwareupgrades.however theipprotecontproteploctionsupshethenetworkits基于nextevolutionsteptherelease4architecture，Figure 4. Here，thegsigmscoreisreportedwithanip网络基础架构的语音通信技术themcsmsevervolultsintotwoseparatecomponents :媒体网关(mgw ) andanmscserver (MSS ) . thisessentilybreaksapparttherolsofconneconnectionandconnectioncontrol.anmsscanhandlemultiplemgws，making the network more scaleable a1pos (126，268 ) 可以将此包容性合并到3 g网络中thiseextendsiprightacrossthewholesnetwork，allthewaytothebts.thisisreferredtoasther or the release5architecture asshowinnfigure5. the HLR/vlr/eiraregeneralisedandrefrredtoasthehlrsubsystem (HSS )现在， 最后一个remanstoftrationalltecomminstinganetoprotecomplementationtheip协议andgeneralisedforthetransportofmanyservicetypes.real-time ngtheinforanewnetworkdomain，the IP多媒体子系统(IMS )currently the3gppareworkingonrelease6hichpropurposstocovealsassnotaddressedifrozenreleases.somecallumts版本6 ganditinconscuressis ngofhots potradioaccesstechnologiessuchcaswirelesslan。1.2 UMTS软驱和TDDlike any CDMA system ustmentaityawidefrechichtooperforefectivelyspreadsignals.thedefiningcharacteristicofthesystemischipsetrate wh ichichiisthewidthofonesymbolofthecdcode.umtsuseschichips3. 84 mm chips/sandthiscontrisconvestoarrequirequiredspectrumcarrierof5MHz wide.sinceiswiderthanthe1. 25 mhzneededfortheexistingcdmaonesystem，THz那里实际上有两个无线电技术。 UMTS umbrella : UMTS软驱和TDD.fddstandsforfrequencydivisionduplex， and like GSM separateforeartiffricintheuplinkanddownlinkbyplacingthematdifferentfrequencychannels.thereforeartiffremonanacturemum locatedtoallowmettoallowmettorunanetwork， hencethetermpaired spectrum. tddortimedivisionduplexrequiresonlinefrequencychannel anduplickinkanddddownlinktrafficareseparatede nttimes.theitu-tspectrumusage，as shown in figure6for discs 1920-980 mhzforuplinktraffic， and 2110-2170 mhzfordownlink.theminitoryallocationanoperatorneedsintwopaired5MHz信道one for uplin