数据库外文翻译

DesignandImplementationofSMSSecuritySystem

forWirelessEnvironmentYan-Ha1,Hea-SookPark1,Soon-MiLee1,Young-WhanPark1,andYoung-ShinHan2Abstract.Thispaperaimsatdevelopingcommunicationmoduleandapplicationprogramforclientmanagementmoduleanddevelopingdatabasemanagementmoduleandmanagingwirelesscommunicationfacilitiesforserversystems.Toconstructtheseaims,wehaveadaptedDESalgorithmandresearchedonencryptinganddecryptingmoduledevelopmentapplicabletoSMSSecuritySystemandoptimizemodulesizeandprocessingspeed.Inaddition,theXMLtechnologyisappliedtoencryptonlythecontentsofthemessageinawaytoreducethevolumeofdatatoprocessandshortenthetimetoencrypting.Introduction1.1BackgroundoftheStudySMS(ShortMessageService)isatwo-waymobiledatacommunicationserviceformobile(cell-phones,PDA)mayexchangeshortmessageswithoutadditionalequipment.SMSiswidelyuseddomesticallyduetotheaccuracyandpromptnessandotheradvantagesofSMS,andGSM(GlobalSystemAssociation)reportedthat19billionmessagesweretransmittedpermonthworldwidelastyear.Inaddition,theon-goingresearchesarefocusingonthesystemresearchanddevelopmentforM-CommercebyusingtheadvantageofSMSunderthemobileInternetenvironment.However,therearestillinsufficienteffortsinresolvingtheshortageofSMS,theissuesofsecurity(exposingoralteringthemessage).Theseshortagesmaybecomethefactorsininterferingwiththesafee-commerceenvironment.Therefore,ifthesecurityofSMSisstrengthenedtoremovetherisksoninformationexposureandalteration,itwouldbeappliedeffectiveontheareasofservicesonorderofgoodsforM-CommerceandE-Commerce,proceedpayment,confirmationofpayment,forwardingofelectronicreceiptandothers,servicesonbalanceinquiry,transfer,introductionofnewfinancialproductonmobileinternetbankingservice,andservicesonvariousauctionservice,reservationservicearea.Inthisthesis,inordertopresentthemessageexposurebyathirdpartyandensuringalterationofmessagesfromtheSMtransmission,thesecuritysystemforSMSwiththebasisofapplyingtheencryptiontechnologyistobedeveloped.Forthispurpose,theDESalgorithmistobeappliedwiththeappropriatealgorithmtousethesmallresourceofmobiledeviceeffectively.Furthermore,thisthesisappliedtheXMLwhenencrypting/decryptingofthemessages.TheadvantagesofapplyingXMLare,first,whichthevolumeofdatatoencrypt/decryptdecreases.Therefore,itreducesthetimerequiredanduseofthesystemresourceless.Second,intheeventthattheinformationofthepartnotencryptedisrequired,thenecessaryinformationmaybeusedwithoutthedecryptionprocess.ExamplesarethesenderID,receiverID,sendingdate,andtitleofmessageandothers.Third,theencryptedpartisnottobeparsingpriortodecryptthattheefficiency.RelatedStudiesSMSrelatedresearchesaremainlythestudiesonsystemstructuring.That,onthesystemtodeliverthestockinformationwithvoiceisdevelopedanditdesignedtheVoiceXMLservermoduleforstockinformation,SMSservermoduletoperformtheauthenticationprocedure,thePSTNnetwork,CTImoduleforinterfaceandothers.Atthistime,theSMScertificationbasedonrandomdisposablepasswordisattemptedasforthemethodofcertification.From,theexistingSMSisdesignedtooperateonthemainmemorydatastructurethattheDBMSconceptisappliedtopointoutandsupplementtheshortcomingsofrecoveryfunctionsimultaneouscontrolfunctiondeficiency.OnthePGPisappliedontheweb-basede-mailservicesystemtoimprovethesecurity,andusetheappletandsubletcommunicationmethodusingthejavalanguagetoresolvethesecurityissuebetweentheclientandserver.Atthistime,inordertoencryptthemessage,itappliestheIDEAalgorithmofsecretkeymethod,andatthistime,theRSAalgorithmofopenkeymethodisappliestoencryptthesecretkey.proposedthesafeinstantmessengersystemthatanindividualuserencryptstheindividualinformationthatissenttothemessengerserver,andselectivelyencryptstheinformationdeliveredbetweentheuserstoresolvethepotentialsecurityissues.And,thesystemdesignismadeonthebasisofdiffusedprocessingenvironmentbytheJAVARMIthatsavesthecommunicationoverheadcomparingtotheclient-serverstructure,andtheDESencryptionalgorithmisusedfortheencryptionoftransmitteddetails,andtheexchangeoftheDESencryptionkeyusestheDiffie-HellmankeyexchangemethodandtheRSAencryptionalgorithm.TheDesignandImplementationofSMSSystem3.1SecurityRequirementsofSystemInthisthesis,thesecurityrequirementneededtothesystemunderthemobileenvironmentispresentedasfollows.First,inordertomaintaintheconfidentiality,thesecretkeyusestherandomnumbergeneratortogenerate1024bitsofrandomnumbers,andinordertokeepthesecretkey,itusestheDiffie-Hellmankeydistributionalgorithm.Second,intheeventthereceivergetsthemessagewhendesigningthedatabaseforthenon-repudiationfunction,itshallbeabletoconfirm.Third,forthemobileauthenticationanduserauthentication,thedatabaseisdesignedaccordingly.3.2StructureofSystemTheentirestructureoftheSMSsystemisliketheFig.1.Theclientperformsthefunctionsofmessagemanagementandtransmission,userandgroupmanagement.Iftheclientwishestotransmitthemessage,itlogsinontheserver,preparesandencryptsthemessageandtheencryptedmessageistransmittedtotheserver.Themessagepreparedatthistimebecomestheencryptionwiththesecretkeyoftheclient.Ifanotherclientreceivesthemessagesfromtheserver,receivetheencryptedmessageafterloggingin.Themessageencryptioninitsownsecretkeyisdecrypted.Themessagemanagementfunctionofserverislargelydividedintotwostages.Serverdecryptstheencryptionmessagetransmittedfromtheclient,thenencryptsagainwiththesecretkeyofthereceivertostoreinthedatabase.Servermakesthecontentsoftransmittingmessagesunabletoread.Ifthereceivingclientwantsthemessagereception,theencryptedmessageisforwardedaftertheclientcertification.Atthistime,thesecretkeyoftheXMLManagerencryptsthemessage.Ifthereceivingclientwishestoreceivethemessagefromtheserver,loginfirstandthenusetheindividualsecretkeytodecrypttheencryptedmessage.ImplementationTheserverofthedevelopedSMSsecuritysystemisimplementedonthecomputerwithIntelPentiumIV2GHz256DDRRAM,andthedevelopmenttoolisusedofVisualStudio6.0.And,inordertodeveloptheclientprogram,theEmbeddedVisualStudio3.0andPocketPCSDKareusedontheabovePC.And,inordertotesttheprogram,theserverprogramdevelopedfromtheabovePCisimplementedandtheWinCEimplementstheclientprogramontheCompaqIPAQusedastheOS.4.1ClientImplementation4.1.1ClientMessageReceptionFunctionFig.2istheinterfaceofClienttoreceivethemessages.Throughtheseinterface,thereceivedmessagemaybereadorprocessed.

ReadMewMcooaack1-!-i；nnrifbtli)whnfalitlA1IrtWHITiAAlit1m祐pfim-1t-t1{.ihFfcr.k-^■1i|j^irkTud L?lli11>|200B-1I：-17T\IujsmleewhiIatoda^meeting!trAr.isi^Arl1pi..2Oty11i/T-t7NoNr.胃1I•Fig.3.TransmissionofMessage4.1.2MessageTransmissionFunctionFig.2.DecryptedandReceivedMessagesFig.3showstheuserinterfacetoforwardnewmessages.Throughthisscreen,themessageistransmittedtotheentiregroupdesignatedortooneparticularuser.Atthistime,pressthetransmissionbuttontoforwardthemessagethatisinputtedonthe“content”windowisencryptedontheDESalgorithmbyusingthe“userpassword”oftheuser.TheexampleofamessageinputtedthroughtheuserinterfacetoaXMLdocumentformisshowninTable1.Fig.2.DecryptedandReceivedMessagesTable1.XMLDocument5ioii=111.0"E,iicocliiig="eiic-ki11?><msginfo><Nuir>Se_0001N</Nnin><Senci_ID>edpsphs<JSend_ID><Rec\_ID>wrliite</RecvID><Recv_GiTnip>sni5</Rec\_Girmp><:M3g_Title>FiClpaperandregisuatioui</Mss_Title><Msg>Fullpape-randirgisU'ationaiT-duebyJanuary31.2004.<7Msg><Send_Date>2003-l1-17</Send_Datr>TheXMLdocumentthatencryptedtheXMLdocumentofTable1isthesameasTable2.Table2.TheEncryptedXMLDocument<Qxinlvcrsian="1.0'encodiiig=''euc-kr"?><DocEncn|)teclElenientaLgoritlmi="DES/CBC<PKC：S?Padcthig"contentTxpe="trxt/xinl”encodings"base64"iv=TPjfzihsNvA=1,>AtIvI4n+GOoo6pA\^7)dNJyZY4AD4Tt6Q/fitiBJS7FaKjouxDjyBH^v==</D□cElicrptedElentent>5sginfo><：Num>Se_0001N</Nuitl><Send_ID>€dpsplis</Seiid_ED><Rrcv_ID>whLte</Recv_ID><Rccv_GLOUp>sms</Recv_Group><EnciptedElenientalgod血站DES/CBC/PKCS5Padding"conteutType=,Jtext/xturencodingsHUase64''ivlucTPbRXyMY='>NfPTROLpBJR4aE5?biMiiJiYaOjaluMAIcdGPOpiFKysO\v=</Encrx'pteEleiTL€iit><Send_Date>2OO3-l1-17</Sencl_Date>C/insginfoA

Table3.ComparisonWithOtherMessengerSystemComparedItemMessengerSystemSMSSystemSystemwitli-□m 5ecuric\:tunctionSystempro-vidiii吕號cnrityfkmctionSystem^'ithoutsecinit\TfimctioiiSysteuipnn^idingsecmitvTfnncHonIniplenientedSystemICQ[11].MSN[12].UIN[13]MaXIM[14]ManySysteuipurposedinthissnidyApph^iii^Al^oritliinNoneRSA.DESNoneDESXMLSecurityNotsupportedNotsuppoi'tedNotsuppoiledSupportedMessageConfidfntialiry7NotsupparirdSuppoiiecLNorsupportedSupportedSenderAutluenticationNotsupportedSupportedNotsupportedSuppliedDBStoi-a9；eFunctionNot£1耳）卩ortedSuppoiled.NotsupportedSupportedMobilityNotsiipportedNotsupportedSuppm:te-dSupportedEquipnentDesktopDesktopPDA.MobilePhanfPDA.MobilePhoi疋4.2ServerImplementationWhentheserverprogramisimplemented,itgeneratesthescreenasshownonFig.4.Theservermanagermayconfirmthesender,receiver,groupID,message,sentdate,receiveddateandothersrelatedtothewaitmessagethroughthisscreen.Inaddition,theservermanagermaydeletetheunnecessarymessagesfromthedatabase.Atthistime,themessagedisplayedonthescreenisencryptedthattheservermanageralsoisnotabletoconfirmthemessage.FilsFrlltRfinnrrlVIrwIInfnfMnnssgnr：FilsFrlltRfinnrrlVIrwIInfnfMnnssgnr：Delatethes@Is：匚t<sdmB^s曰geDeistsallmessagesViewthesel@cti&dmessageFig.4.ApplicationofServerSide4.3ComparisonwithOtherMessengerSystemThisstudyisastudyproposedtoovercometheshortcomingsinthesecurityaspectcomparingtothepossibilityofutilizationfortheSMSsystemthattheintentistoevaluatethefunctionalaspectsrelatedtothesecurity.ConclusionandFurtherStudiesInthisstudy,safemessageuseenvironmentisimplementedbyapplyingthesecuritytechnologyontheSMthatisbroadlyusedunderthemobileenvironmenttoday.Forthispurpose,itappliesthesecurityalgorithm,DES,ofsymmetrickeymethod,andimplementstheSMS.SMSisconsistedofDBservermodule,encryption/decryptionmoduleandserverinterfacemodule.AnditisdesignedandimplementedbyencryptingthemessagepreparedbythesendertostoreinthedatabaseoftheSMSserver,andperformthereceptionanddecryptionofthemessagebythereceivingparty.SMSthatisdevelopedbythisstudyisevaluatedassatisfyingallsectors,suchasmessageconfidentiality,senderauthentication,mobilityandotherswhencomparedtotheothermessengersystems.ThesystemimplementedbythisthesisisevaluatedasapplicabletomanyfieldsservicedunderthemobileInternetenvironment.Inparticular,theXMLtechnologyisappliedwhenencryptingmessage,itencrypts/decryptsonlythecontentsofthemessagetocutdownthevolumeofdata.Itincreasestheconveniencetoconfirmthecontentsnotencryptedwithoutdecryptentirevolume.设计和实现短信安全系统的无线环境Yan-Ha1,Hea-SookPark1,Soon-MiLee1,Young-WhanPark1,andYoung-ShinHan2摘要本文旨在发展通讯模块和应用程序如客户管理模块，开发数据库管理模块和管理无线通信设施服务器系统。为了达到这一目标我们已经改编了DES算法使它适用于短信安全系统的加密和解密模块、优化模块尺寸和处理速度。此夕外XML技术只应用到信息内容的加密减少了大量的数据处理,缩短时间加密。1.介绍1.1研究背景SMS（短消息服务）是移动（手机、PDA）的一种双向移动数据通信业务，不需要其它的设备就可以交流短信。由于SMS的准确性、快捷等优点国内广泛使用手机短信，GSM（全球系统协会）报道,去年全球每月转发短信190亿。此夕,主要研究的系统和开发的移动电子商务所利用的SMS是在移动互联网的环境内的。然而,在解决短信的问题上的努力仍有不足,安全问题（的暴露或改变）。这些问题因素可能会破坏电子商务环境的安全。因此,如果短信服务更强健了信息暴露和改造的被移除了,它就会被服务领域有效的采用,如移动商务、电子商务中的货物订购，支付,确认付款、电子发票的签收等。总而言之关于银行服务的新的移动金融产业如咨询，转账，收入还有各种各样的拍卖服务、预订服务。在这篇论文中，为了呈现信息被第三方曝光以及信息在传输过程中确实被改变，SMS安全系统是以加密技术为基础开发出来的。为了达到这个目的，DES算法在适用的算法中占用的资源较少用于移动设备比较有效。此外，论文在短信的加密/解密中采用XML技术。运用XML的优点：第一，它大量的减少了加密解密的运算量。因此，可以减少运算所需的时间和占用的资源。第二，信息中有些部分是不用加密的，当然这些部分也不用解密。如发送者，收件者，发送日期，短信标题等等。第三，信息是不能被前面的译码有效的解码的。2.相关研究与SMS相关的研究主要是系统的构建。系统采用声音的方式传送货物信息已经十分发达并且开发了XML货物信息服务模块，SMS服务模块执行程序的认证，网络的连接，CTI接口模块等等。同时，SMS认知是基于一次性密码认证的方法认证的。现有的短信是被设计用于主存数据结构数据的，用数据库概念可以于指出并恢复SMS功能的不足改善同时控制功能存在的缺陷。应用PGP互联网电子邮件服务体系增加安全性,同时使用小程序底层通讯和java语言来解决客户端和服务器之间的安全性问题。同时，为了给信息加密，使用算法密钥的思想方这里使用RSA算法为公开的密码加密。提出的即时通信系统是每位用户加密后发送给服务器,选择性的加密信息在用户之间传递可以解决潜在的安全问题。系统基于JAVA，RMI所编的散处理环境比客户端-服务器更节约空间，DES加密算法加密了传输的细节，交换密钥时使用、使用diffie-hellman关键方法和RSA加密算法。3.SMS系统的设计与实现系统3.1系统的安全要求在这篇论文中,在移动环境下提出了对系统的安全需求如下。第一,为了安全，密钥是1024位随机发生器产生的随机数字。并且为了秘钥的安全，密钥使用diffie-hellman密钥分配算法。第二，如果得接收消息者的数据库中,有设计的确认功能,它才能确认。第三，第三,手机认证和用户认证、为数据库的设计提供依据。3.2系统的结构整个SMS系统的结构如Fig.1Fig.1.SMS系统的结构客户端的功能是信息管理和传播,用户和组的管理。当用户想传输信息时，登入服务，准备并加密信息并把加密信息传送给服务器。此时用户所准备的信息变成了加密信息和密钥。当另一用户收到了从服务器发来的信息，在他登入后就会收到加密信息。这信息在输入

了密钥后就可以解密。服务器的信息管理功能主要分为两个阶段。服务器解密客户传递的加密信息，服务器使用接收者的密钥加密信息并存入数据库中。服务器使在传输过程中的信息时不可阅读的。如果接收者想接收信息，在用户同意后密文是可以转发的。这时，XML管理者使用密钥加密信息。如果接受者想从服务器接收信息，先登入在使用各自的密钥解开密文。4.实现SMS安全系统的服务器需英特尔奔腾IV2GHzDDR256MB内存的电脑，开发工具是VisualStudio6.0。为了开发客户端程序，在电脑中装入VisualStudio3.0和PCSDK。为了测试程序，服务器由上诉pc开发，用户端在用wince操作系统惠普笔记本电脑上。4.1客户端4.1.1客户信息接收功能Fig.2是客户端接收信息的界面，通过这些界面,收到的信息可能被读或处理FlcadMowMcocaqcH&frcshkNiimhnri-innrirBrII)whIitlA1IrtW^TiA A1it1Jnfnpfim-i1-t11.IhPtr.k-V*^1ip^irkTud Lrtli11>i2003-11-17fxlusmEeewhitatodaj^meeting!t1■曰dzarl1pi..2£JU3111/jnm-1T-17NoNr.’1I►D&leteMessageDeleteAHMessagesExitFig.2.信息的接收和解码GSkmdi—iIO= 0FSec&iw&rID: iteIT'h^inkyouI1hiaverec-eived5^ourmness--aq&ri口wlIInvt=tn司wwmu-ltillIs=l吞”mm■rp壬打口n*Fig.3.信息的传递4.1.2信息传输功能的实现Fig.3显示了用户传输新消息的界面。更具屏幕显示,信息可以传送给整个小组或某一指定用户。在这段时间,就是按下传输信息按钮，在输入窗口内的内容就会被加密，使用的是基于用户密码的DES算法的方法。例子是一条信息通过用户界面转换成XML文档表格如Table1。Table1.XML文档l e-ncoiliiig^Neiic-ki-''Q><msginfD><Num>S£_00d1N</Nuin><3encl_ID>eipsphs<JSeacE_ID><Rec\_ID>^liite</RecvID><Rec\_Giion.ip>siiis</Re-c^_Gimtp><:Msg_Title>Fiillpaperandregisuarinn^</Msg_Ticle><Alsg>Fullpape-randltgisuationaircluebyJanuary31.2OO4.</Msg><Send_Datc>2003-11-17<7Send_Dare>相对与Tablel的文档加密过后的XML文档如Table2。Table2.加密后的XML文档vcrsian=L.OencodiiiS="euc-ki'"?><DocEncn^)teclElenientalgantlun="DES/CBCfPK.CS5PadctmgcantentTxpe="trxt/xinl"encodiug="tiaset>4"i—"TPjfzihsNvA=1'>Athl4n+GOoo6pAXT\7)dNJyZY4.\D4Tt6Q/fibBJS7FaKjouxajyBHw==</DdcElictptedEleuient>*^tnsgiiifo>*：：Nuni>Sr0001N</Nuiil><Sencl_ID>edpspdis</Seiid_LD><Rjecv_ED>w]ute<7Recv_ID><Rtrcv_Group>siTLS</Rec\_Gioup>cEnciptedElenientalgoiitliiR=DES/CBC/PKCS5Paddmg'conteiitTy text/xinl''encodnig=HLase64'ivIircVPURXyMY='F>NfPTROLpBJR4aE55hMiiJiYaOjalaMMcdGPOpiFKysOAv=</EncrxpteELement><Sencl_Date>2003-11-17</Sencl_Date>

Table3.与其他短信系统的比较ComparedItemMesseneerSystemSMSSystemSystem吐ith-□ut securityftinctionSystempin-\MingsecurityfunctionSystemwithoutsecinityTUnctionSystemprovidingsecurityfunctionIiiiplenienteciSystemICQ[11],MSN[12].UIN[13]MaXIM[14]ManySystempioposedintliisstudvAppkpiiigAkoritlunNoneREA*DESNoneDESXMLS比urityNotsupportedNotsuppdtedNotsupportedSupportedMessageC□nfidentialitx7NotsiippottedSupposedNotsupportedSupportedSenderAutlirnticationNotsupportedSupportedNotsupportedSupportedDEEtoan罕FunctinnNotsi甲卩ortedSupposedNotsupportedSupportedMobilityNotsupportedNotsuppoiteclSuppai'tedSupportedEqiiipmentDesktopDesktopPDA.MobilePhonePDA.MobilePlione4.2ServerImplementation当服务器程序执行时，它会产生屏幕显示如Fig4。对于等待的信息服务器管理者可以通过该屏幕确认发送,接收、查看组身份、报文发送日期、收到的日期及其他相关信息。此外,服务器管理者可以从数据库中删除不必要的信息。当然，服务器管理者屏幕上的信息时加密的，管理者也不能读取信息。FilsFrllTRfii?nrrlVIrwLl£tofMessages口咎FilsFrllTRfii?nrrlVIrwLl£tofMessages口咎I弓耳曾th畔，早I•匚t启dmessageDelm©百IImessage©th®导常1耳g■（牛dmessageFig.4.应用服务器端4.3与其他短信系统的比较本文提出了关于利用SMS系统如何克服在安全方面的可行性比较。其目的就是评估相关层面功能的安全。5.结论与未来在这项研究中，如今，为了实现了信息安全技术广泛用于SM移动环境下的信息使用的安全。为了这个目的，运用DES安全算法、关键密钥方法，并使用了SMS系统。SMS系统是由数据库服务器模块、加密/解密模块和服务器接口模块组成。并且它由发送人准备的信息经过设计加密传入SMS服务器的数据库中，而接收和解密信息是由接收者完成的。和其它的信息系统相比，开发的SMS系统在各个方面都是令人满意的，如信息保密性，发送者认证，移动性等等。本系统可以适用于许多移动互联网环境下的服务领域。特别指出，XML技术用于信息加密，它只加密/解密信息的内容可以减少大量的数据。它增加了认证内容的方便性没有加密解密整个数据。ImprovetheGSMnetworkcapacityplanningWiththerapiddevelopmentofGSMmobilebusiness,andensuringthequalityofcommunicationsunderthepremiseofmaximizeGSMnetworkcapacityisalwaysnetworkoperatorssought-aftergoal.ThetraditionalmethodsofGSMexpansionisthebandsplitandexpansion,butnowgetnewspectrumresourcesthepossibilityisnotbig,inthecallcentersforinterferencewiththelimit,districtdivisionalsocrippled,soitismorecloselyfrequencyreusetechnology,establishingmicrocells/slightlyhoneycomb,constructionSM900/1800double-frequencynetworkandnetworkoptimizationsolutionGSMnetworkcapacityhasbecometheimportantmeans.1.DistrictsplittechnologyDistrictsplittechnologyistoincreasethecapacityofthenetworkcoursepreferredplan.GSMearlyarrangement,themainproblemistosolvethecover.Inthespectrumresourcesbounteousarea/period,alongwiththeincreaseoftheuser,butwilltheoriginaldistrictsplitintomorecoverageareaislesserareaorincreasethenumberoforiginaltransmits,soastoachievethepurposeofexpansion.Throughthevillagesplitortransmitsnew,overthebasestationnumber,number,numberofchannel,whichtransmits,traffic,subscribersareincreasedsubstantially.Improvetheutilizationratioofthecommunitydividedspectrumkeyliesintheareaofreducingtheunitarea.Choosedistrictsplitexpansionmethodshallcomplywiththefollowingprinciples:ensurethathasbuiltthebasestationcancontinuetouse;shouldholdthefrequencymultiplexingmethodofregularityandrepeatability;trytoavoidorreducethetransitionzone;toensurethatfuturemaycontinuedistrictdivision.Thesplitinthevillagetovillagetothemainmethods1:3anti-secessionlaw;Thesplitinthevillagetovillagetothemethodandtohave:"anti-secessionlaw;Thevillagefordirectionaldistricttosplitthemethodsare:1x3x4anti-secessionlawand1x6x3anti-secessionlaw;Directionaldistrictsplitthemethodfordirectionalhave:hexagonalsidecenteranti-secessionlawandhexagonalvertexanti-secessionlaw.2.TheexpansionandthefrequencybandclosemultiplexingtechniqueFrequencyband,ofcourse,istheidealofcapacityexpansionmethod,butinthecurrentcase,getnewspectrumisunlikely.Atpresentinthe900MHzbandunicom6MHzresources,inadditiontotheindividualthehotspot,cansatisfytheneedforbasic.TelecomGSMfiveperiodexpansionafterGSMnetsfrequencyrangefor:898.6-908.8MHz,total10.2MHz.TheexpansionplaninprincipleofAnetworkextendstothebandwillbe885.0125MHz,GSMnetsfrequencybanddownto14.4MHzexpansion,theuseof23-94numberfrequency.Atpresent,thetelecomGnetsbasestationinmanyareasalreadyverycrowded,partofthedistancebetweenthebasestationonly-meters,theappropriateselectionofhailhasmoreandmoredifficult.Thedistancebetweenthestandingtooclose,leadingtothesamefrequencyandadjacenttheincreaseoffrequencyinterference.Inaddition,thehighertheantennagain,therestrictedinthebeamwidthofthenarrow,ifstandtooclosetothedistance,themobileinantennabeamoftheLordtheprobabilityincreasegreatly.Inaddition,Anetsfrequencyshiftroomalsoisnotverybig,therefore,thespectrumofthespaceexpandisverylimited.However,duetotheGSMsuchasGMSK,balancedmodulation,mixedcodingmethod,especiallyalsoprovidessomeotheraimstoimprovespectrumefficiencytechnology,suchasfrequencyhopping,thecontinuousfiring,powercontrol,halfratechannel,diversityandmobileauxiliaryswitch,receive,soastoreducethenetworkofthesamefrequencyandadjacentinterferencesourceindexrequest,thefrequencyoftheclosereusepossible.hopping.Frequencyhoppingisaccordingtosomefrequencytransmitsjumpingintheseries,itincludesbasebandfrequencyhoppingandrffrequencyhoppingtwokinds.Frequencyhoppingroleistoprovidethefrequencydiversity,andimprovethesystemofanti-disturbanceability,resistancetodecline.Thecontinuousfiring.UsingDTXtechnology,mayreducethesystemoveralllevelofinterference.Powercontrol.Thisisalsoreduceinterferencesoastoimprovethecapacityoftheeffectivemeans.Halfratechannel.Thiscanmakethesystemcapacitydoubled.Diversity.Diversityhavevariousforms,usediversitytechnology,canimprovetheabilityofthesystemofdecline.ThecloserfrequencymultiplexingtechniqueInthespectrumoflimitedcircumstances,adoptmorecloselyfrequencymultiplexingmethodisundoubtedlyimprovesystemcapacityofoneofthemostdirectway.CanyouuseGSMfrequencymultiplexingmethodmainlyhaveliver:7villagemultiplexingmethod,4x3multiplexingmethod,3by3multiplexingmethod,4x3and3by3mixedmultiplexingmethod,2x6multiplexingmethod,1x3multiplexingmethodandConcentriccirclestechnologyandMultiplereuseMRPstyleandetc.sevenofthebasestationmultiplexingmethod:Thesevenbasestationareaforareusethereuseofthegroupusedinlowtrafficwayoruserdensitysmallerareas,forthegeneraltobasestation,theD/R=4.58,withfrequencymultiplexingdistanceisfarther.4x3multiplexingmethod:Thisis"900MHzTDMAdigitalpubliclandcellularmobilecommunicationnetworktechnologysystem"recommendedthereuseoftheway,andisalsothemostcommonandGSMsystemthemosttypicalmultiplexingmethod.Forclover60degreesantenna,theD/R=6;For120degreesantenna,theD/R=3.46theclover60degreeswhenwirelesswithfrequencyinterferencebetterperformance.3by3multiplexingmethod:Thisis"900MHzTDMAdigitalpubliclandcellularmobilecommunicationnetworktechnologysystem"recommendedthereuseoftheway.3by3multiplexingmethodandfrequencyhopping,DTX,powercontrolareusedtogether,withfrequencyinterferencerequirements.Butinthefollowing6MHzbandwidth,can'tprovideenoughfrequencyhoppinggain,sopoorperformance.2x6multiplexingmethod:ThisisMotrolaproposedtosolvehightrafficareasoffrequencyreusemethod.Themethodinthedirectionofthedifferentantennahasadifferentfrequencyreusedegree,theD/Rlessthan3by3multiplexingmethod.1x3multiplexingmethod:Thiswayisthemostcloselymultiplexingmethod,itsmainfeatures:Applicabletoanarrowfrequencyband,capacitymoreconcentrated,donotneedmanyofthebaseareas;ButinsmallerNumbersprovidelargerbasestationcapacity;Theneedtopartoftheloadingmethods,namelytransmitscan'tusefull,sendandreceivelettermachineforabouthalfthenumbersoftware-processable;Needtoadoptrffrequencyhopping,powercontrol,discontinuouslaunch,antennadiversitytechnologyetc,inordertoreduceinterference;Donotneedtochangetheexistingnetworkstructure.But,althoughthiswayfrequencyutilizationrateisveryhigh,butthesystemdisturbanceincreaseisverybig,ifuseanti-interferencemeasuresnoteffective,mayhavegreatinfluenceonthequalityofnetwork,soshouldbeusedwithcaution.concentriccirclestechnology:Technologyistheusualconcentriccirclesareadividedintoouterandtheinner,theouterlayerofthecoverageforthetraditionalcellularvillage,andtheinnercoveragearemainlyconcentratedinthebasestationnearby.Inaddition,insideandoutsideofthecoefficientoffrequencyreusearealsodifferent,outergeneraluse4x3multiplexingmethod,andtheinnerusedtheclosermultiplexingmethod,suchas3by3,2x3or1x3ways.Accordingtotherealizationoftheconcentriccirclesindifferentways,canbedividedintoordinaryconcentriccirclesandintelligentdoublenets(IUO)twokinds,theessentialdifferencebetweenboththelaunchoftheinnerpowerandinternalandexternallayerofswitchingalgorithm.Thelaunchoftheinnerordinaryconcentriccirclesofpoweringeneraltobelowouter,soastoreducethesamefrequencyinterference,whichgenerallyisbasedontheouterlayeroftheswitchpoweranddistance.AndIUOinsideandoutsideofthelayerarequitethesametransmissionpower,andbasedonC/Iswitch.Toimprovethecapacityofordinaryconcentriccirclesabout10%-30%orso,improvequantityisnotbig,IUOwaytoimprovetherelativelylargecapacity,aregenerally20%-40%,andcanimprovethecapacityinbasedonthecallqualityguarantee.MRPway:MRPwaywillallavailableisdividedintoseveralgroupstransmits,eachgroupasaseparatelayertransmits,thefrequencyofthedifferentlayerswithdifferentmultiplexingmethod,frequencyreuseclosestepbystep.ToensurethesafetyoftheBCCH,usedintheBCCHtransmitstheMRPnumbershouldnotlessthan12.AccordingtothedifferentmethodofgroupingTCH,MRPandcanbedividedintostrictMRPandimprovedMRP.MRPmultiplexingmethodhasthefollowingfeatures:Largecapacitycanbeimproved,in7.2MHzbandwidthcases,than4x3reuseimprovetherateof47%;Channelallocationflexible;Canreleaseasomefrequenciesusedformicrocells;Usingbasebandfrequencyhopping,easiertoachieve.InusingMRP,shouldpayattentiontothefollowingquestions:Mustusefrequencyhopping,powercontrol,suchasDTXanti-jammingmethod,thisalsoisthepremiseofMRPtechnologyapplication;UsingMRPtechnology,attentionshallbepaidtotheorderoffrequencydistribution.GenerallyshouldfirstBCCHdistribution,andthenTCH5distribution,thenTCH4distribution,untilTCH1;Differentareaofthebasefrequencyrespectivelyplanning;AccordingtothespecificinterferenceofadjustmentadjacentregionsSettings.Fromshenzhenandshandong,astheuseoftheland,wecanseetheMRPtechnologycanaccordingtocapacitydemandandtrafficdistributionforflexiblefrequencyplanning,butgraduallyimprovenetworkcapacitythanusingonly3by3reusenetworkcapacity,high,and1x