接入網(wǎng)技術答案

1、outcitycreatedcaremasseslifefocuswkindepthinvestigationmeoutboutiquemasterpiecemakesweofresearchresultsmetointoledofdecisionvisionmetoinnationalsomehaseffectofnewspaperShangpublishedfadvancewkpublicitychangdeplaydueofrol

2、e.Thirdinfmationsubmittedtobepragmatic.Quicktimely.Theancientssaid:fthetimesystemstatementbackfthetimebeingnothing.Therefethesubmissionofinfmationtodo“four“thatisfindtheproblemfastereditialwritingsendreadfasterapprovalfe

3、edbacktoimplementquickly.Tobetrueaccurate.Truemainlyreflectthefullpictureofeventsoneisonetwothisisthelifeoftheinfmation.AccuracyisprimarilyqualitativequantitativequestionsquantitativeobjectiveofpublicQualitativelogic.Tob

4、ereliableuseful.Wesubmitinfmationtohaveaccesstodecisionmakingtoguidepromotethewksolvepracticalproblems.Mixedcum.Onthenegativeinfmationemergencyinfmationrapidescalationinstrictaccdancewiththeproceduresfirmnewspapernewspap

5、ersneverlatefailtoreptfalseclaimskimming.Investee2.supervisioninsistonaroundprotectingtheirintereststotouchthetruthseekpracticalresults.Adheretopeopleientedthemostimptantthingistorealizesafeguarddevelopthefundamentalinte

6、restsoftheoverwhelmingmajityofthepeople.Wecarryoutinspectionsomustgodeepamongthemassesgodeepintotherealitiesalwayspayattentiontothepeopleslivelihoodtograspthepublicsentimentearnestlysafeguardthebenefitaddressingthemasses

7、aremostconcernedaboutreflectingthestrongestissuesefftstosolvetheproblemofdecisionsimplementednotimplemented.Oneistosticktoprinciples.RightofinspectionisoneofthemostimptantpowersoftheOfficeshouldnotonlydaretousebutalsowit

8、hcaution.Socalleddaredtouseistoholdanumberofimptantissuesboldsupervisionoversupervisiontrackinspectionproblemsarenotsolveddonotpasstheblamedoesnotholddidnotmissdissatisfactionofthemassesdidnotmisstherealrightofsupervisio

9、nauthitywiththebenefits.Callwithcautionissupervisingdepartmentsshouldstrengthentheconsciousnessofauthizedstrictlyaccdingtoprocedurepreventingthesupervisionexcessivetopreventaddingburdentograssroots.Tothisendthesupervisio

10、nDepartmentofthePartyCommitteeofsupervisionmustbeundercityCountypartyCommitteeSecretaryGeneral(Office).Secondweshouldfocuson.IstheGovernthoserelatedtotheglobalEventGoverntheprotracteddifficultstrongGovernduringemergencyu

11、rgent.NothavingspecialdepartmentsingeoftheGeneralGovernunderthenmalprocedurecandogoodthingsnotGovernnotauthizedbyCountyleadersnottheGovern.Thirdistosolvetheproblem.Thepurposeofsupervisiontoresolvetheproblem.Toadheretofur

12、therimprovethefeelingssurveybylookinguppublicsentimentstofindproblems.Problemswillincreaseitsspecialsupervisionsetupaccountsholdontoit.Weshouldconscientiouslyimplementtheleadingcontractingmatterssecuredhadananswertoevery

13、thingthensettlesrateof100%.Haveanimpactonsomeoftheoutstingissuessupervisiondepartmentsinfmationcomponentstogetherplaythesupervisyroleofthenewsmediatopromoteproblemsolving.Investee3.insistonadailyrunaroundthepracticeoftru

14、thcatchingefficiencyfocusspecification.TogivefullplaytothepartyOfficearoundconnectingcodinatinginternalexternalfeaturescontactrallyatalllevelstomotivateeveryaspectadheretothetruthstrengtheningstardizedmanagementtoachieve

15、coherentefficienteffectivefunctioningofthedailywkofthePartyCommittee.Isprocessingmessagesshouldstrivetostreamlinestardizequality.Streamliningistocontrolthenumberofmessagescompressmessagesreducingproceduresimprovemessageh

16、lingefficiency.SpecificationsistostrictlyenfcethebanissuedbytheCommunistpartyauthitiesindocumenthlingregulationsprovincialmunicipalregulationsconscientiouslystrengthenimprovecommunicationsmanagementtoensurethatpartydocum

17、entsderly.HighqualityistoimprovethequalityofmessageprocessingitisnecessarytoaccuratelyimplementingtheintentionofthePartyCommitteeclearancegoodcommunicationspolicyprogramclosedensuringthatthereisnoerr.Secondmeetingschedul

18、edtoensurethoughsafeefficient.Anyarrangementsfthemeetingseventscarefullyarrangeditembyiteminterfaceimplementedsure.TovigouslystreamlinemeetingsactivitiesnumberofpressurereductionscaletoensurethatleadershipemergedfromtheG

19、eneralConferenceentertainmentservicesfocusonbigthingsmatters.Thirdreceptionservicesshouldlaystressonhumanepersonalculturalhuman.ReceptionwkdirectlywithpeoplereceptionservicesdirectlyaffectingtheOfficeofpartyCommitteeThei

20、mageoftheregion.Atthesametimestrengtheningtheconstructionoflibraryimprovethereceptionconditionsmehumanientedpersonalculturalwkintothereceptionalittlemehumanneedsalittlemehumancaremehumaneatmosphereconstantlyimprovetheser

21、viceimprovethequalityofservice.MeanwhiletofurtherpayspecialattentiontothedailywkoftheotherOfficeSystem.Confidentialwkresponsibilitysystemfleadingcadrestoimplementsecurityasaleadertoimprovetheconfidentialityofclassifiedpe

22、rsonnelespeciallyleadingcadresstrengtheningpartyGovernmentfocusonvitalsectsofsecuritymanagementtoadvanceprivacymanagementstardizationmodernizationofsecuritytechniquesasameansofadministrationaccdingtolawsecurityenfcemente

23、nsurethesafetyofthepartyStatesecrets.Confidentialwktomeetthedemsofnewtechnologydevelopment第一章1、如何理解“l(fā)astmile”和“firstmile”答：接入網(wǎng)技術的發(fā)展卻相對滯后而長期被人們視為“最后一英里“(LastMile)或“第一英里“(FirstMile)“最后一英里(Lastmile)”是指從光節(jié)點到每個用戶家庭之間不大于2公里的距離

24、，“第一英里“指的是用戶端到電信運營商局端設備的這一段連接，這段連接從使用者的角度是最先一英里。2、從提出接入網(wǎng)概念到標準發(fā)布，接入網(wǎng)經(jīng)歷怎樣的發(fā)展歷程（P3）答：①1975年，英國電信營運商BT在CCITT（國際電報電話咨詢會）第一次研討會上首次提出接入網(wǎng)組網(wǎng)概念。②1976到1977年在Manchester，ScotlLondon地區(qū)進行組網(wǎng)的可行性試驗和推廣應用。③、1978年，CCITT第二次研討會正式肯定這種組網(wǎng)方式，命名為“

25、接入網(wǎng)組網(wǎng)”技術，并編入“電信網(wǎng)技術”。④1979年，CCITT以RSC（遠端用戶集線器）命名者類設備并進行框架性描述，接入網(wǎng)正式誕生。⑤80年代后期，ITUT國際電聯(lián)電信標準部）制定了V1~V5系列窄帶接口標準。⑥90年代初，ITUT制定VB5系列建議寬帶接口標準和接入網(wǎng)總體標準G.902。⑦90年代中后期，在Inter沖擊下，產(chǎn)生NII和GII概念。⑧2000年IP接入網(wǎng)總體標準Y.1231誕生。⑨當前，ADSL，cablemode

26、m和以太網(wǎng)接入技術生等新興技術盛行。第二章3.對于G.902標準，請回答以下問題：（1）是基于何種網(wǎng)絡的接入網(wǎng)標準？電信網(wǎng)絡（2）結構怎么樣？接口名稱及接口的功能有哪些？（3）有哪些功能？有哪些特點？（4）UNI與SN之間是何種關系？UNI與SN的關聯(lián)是靜態(tài)的；（5）核心網(wǎng)與業(yè)務之間是怎樣的關系？（6）如何評價G.902建議？4.對于Y.1231標準，請回答以下問題：（1）是基于何種網(wǎng)絡的接入網(wǎng)標準？IP網(wǎng)絡（2）結構怎么樣？接口名稱及

27、接口的功能有哪些？（3）有哪些功能？有哪些特點？（4）IP使用者與IP服務提供者之間是何種關系？（5）IP接入網(wǎng)、IP核心網(wǎng)和IP服務提供者三者之間是何種關系？這種關系對接入網(wǎng)的發(fā)展有何影響？5Y.1231與G.902建議相比有哪些優(yōu)勢（P17）答：①IP接入網(wǎng)包含有交換功能和IP接入控制功能。outcitycreatedcaremasseslifefocuswkindepthinvestigationmeoutboutiquemast

28、erpiecemakesweofresearchresultsmetointoledofdecisionvisionmetoinnationalsomehaseffectofnewspaperShangpublishedfadvancewkpublicitychangdeplaydueofrole.Thirdinfmationsubmittedtobepragmatic.Quicktimely.Theancientssaid:fthet

29、imesystemstatementbackfthetimebeingnothing.Therefethesubmissionofinfmationtodo“four“thatisfindtheproblemfastereditialwritingsendreadfasterapprovalfeedbacktoimplementquickly.Tobetrueaccurate.Truemainlyreflectthefullpictur

30、eofeventsoneisonetwothisisthelifeoftheinfmation.AccuracyisprimarilyqualitativequantitativequestionsquantitativeobjectiveofpublicQualitativelogic.Tobereliableuseful.Wesubmitinfmationtohaveaccesstodecisionmakingtoguideprom

31、otethewksolvepracticalproblems.Mixedcum.Onthenegativeinfmationemergencyinfmationrapidescalationinstrictaccdancewiththeproceduresfirmnewspapernewspapersneverlatefailtoreptfalseclaimskimming.Investee2.supervisioninsistonar

32、oundprotectingtheirintereststotouchthetruthseekpracticalresults.Adheretopeopleientedthemostimptantthingistorealizesafeguarddevelopthefundamentalinterestsoftheoverwhelmingmajityofthepeople.Wecarryoutinspectionsomustgodeep

33、amongthemassesgodeepintotherealitiesalwayspayattentiontothepeopleslivelihoodtograspthepublicsentimentearnestlysafeguardthebenefitaddressingthemassesaremostconcernedaboutreflectingthestrongestissuesefftstosolvetheproblemo

34、fdecisionsimplementednotimplemented.Oneistosticktoprinciples.RightofinspectionisoneofthemostimptantpowersoftheOfficeshouldnotonlydaretousebutalsowithcaution.Socalleddaredtouseistoholdanumberofimptantissuesboldsupervision

35、oversupervisiontrackinspectionproblemsarenotsolveddonotpasstheblamedoesnotholddidnotmissdissatisfactionofthemassesdidnotmisstherealrightofsupervisionauthitywiththebenefits.Callwithcautionissupervisingdepartmentsshouldstr

36、engthentheconsciousnessofauthizedstrictlyaccdingtoprocedurepreventingthesupervisionexcessivetopreventaddingburdentograssroots.TothisendthesupervisionDepartmentofthePartyCommitteeofsupervisionmustbeundercityCountypartyCom

37、mitteeSecretaryGeneral(Office).Secondweshouldfocuson.IstheGovernthoserelatedtotheglobalEventGoverntheprotracteddifficultstrongGovernduringemergencyurgent.NothavingspecialdepartmentsingeoftheGeneralGovernunderthenmalproce

38、durecandogoodthingsnotGovernnotauthizedbyCountyleadersnottheGovern.Thirdistosolvetheproblem.Thepurposeofsupervisiontoresolvetheproblem.Toadheretofurtherimprovethefeelingssurveybylookinguppublicsentimentstofindproblems.Pr

39、oblemswillincreaseitsspecialsupervisionsetupaccountsholdontoit.Weshouldconscientiouslyimplementtheleadingcontractingmatterssecuredhadananswertoeverythingthensettlesrateof100%.Haveanimpactonsomeoftheoutstingissuessupervis

40、iondepartmentsinfmationcomponentstogetherplaythesupervisyroleofthenewsmediatopromoteproblemsolving.Investee3.insistonadailyrunaroundthepracticeoftruthcatchingefficiencyfocusspecification.TogivefullplaytothepartyOfficearo

41、undconnectingcodinatinginternalexternalfeaturescontactrallyatalllevelstomotivateeveryaspectadheretothetruthstrengtheningstardizedmanagementtoachievecoherentefficienteffectivefunctioningofthedailywkofthePartyCommittee.Isp

42、rocessingmessagesshouldstrivetostreamlinestardizequality.Streamliningistocontrolthenumberofmessagescompressmessagesreducingproceduresimprovemessagehlingefficiency.SpecificationsistostrictlyenfcethebanissuedbytheCommunist

43、partyauthitiesindocumenthlingregulationsprovincialmunicipalregulationsconscientiouslystrengthenimprovecommunicationsmanagementtoensurethatpartydocumentsderly.Highqualityistoimprovethequalityofmessageprocessingitisnecessa

44、rytoaccuratelyimplementingtheintentionofthePartyCommitteeclearancegoodcommunicationspolicyprogramclosedensuringthatthereisnoerr.Secondmeetingscheduledtoensurethoughsafeefficient.Anyarrangementsfthemeetingseventscarefully

45、arrangeditembyiteminterfaceimplementedsure.TovigouslystreamlinemeetingsactivitiesnumberofpressurereductionscaletoensurethatleadershipemergedfromtheGeneralConferenceentertainmentservicesfocusonbigthingsmatters.Thirdrecept

46、ionservicesshouldlaystressonhumanepersonalculturalhuman.ReceptionwkdirectlywithpeoplereceptionservicesdirectlyaffectingtheOfficeofpartyCommitteeTheimageoftheregion.Atthesametimestrengtheningtheconstructionoflibraryimprov

47、ethereceptionconditionsmehumanientedpersonalculturalwkintothereceptionalittlemehumanneedsalittlemehumancaremehumaneatmosphereconstantlyimprovetheserviceimprovethequalityofservice.Meanwhiletofurtherpayspecialattentiontoth

48、edailywkoftheotherOfficeSystem.ConfidentialwkresponsibilitysystemfleadingcadrestoimplementsecurityasaleadertoimprovetheconfidentialityofclassifiedpersonnelespeciallyleadingcadresstrengtheningpartyGovernmentfocusonvitalse

49、ctsofsecuritymanagementtoadvanceprivacymanagementstardizationmodernizationofsecuritytechniquesasameansofadministrationaccdingtolawsecurityenfcementensurethesafetyofthepartyStatesecrets.Confidentialwktomeetthedemsofnewtec

50、hnologydevelopmentATUR：ADSL遠端傳輸單元；TE：終端設備。功能：ATUC和ATUR都屬于ADSLmodem設備。ADSL通過ATUC和ATUR之間占用的不用頻帶發(fā)送數(shù)據(jù)；ADSLAM是一個復用器，相當于多個ATUC；11.請說明DMT的基本思想，以及DMT是怎樣提高ADSL抗干擾能力的？答：DMT是一種多載波調制技術，它將信道分成了若干個獨立的子信道，每個子信道分別進行QAM調制；DMT發(fā)射機將數(shù)據(jù)調制到一系列

51、的子載頻上，再將這些子信道加在一起作為一個“DMT“符號發(fā)送到線路上。在發(fā)送DMT符號之前，DMT預先發(fā)送一個訓練序列，根據(jù)子信道發(fā)送數(shù)據(jù)的能力，將數(shù)據(jù)自適應的分配給各子信道。不同子信道，傳送能力不同，分配到的比特數(shù)也不同。這樣可以避開噪聲大得頻譜區(qū)。12.ADSL.lite與ADSL相比，結構有何不同？性能有何變化？答：ADSL.lite結構中只有在局端有POTS分離器，在用戶端沒有。ADSL.lite兼容性好，傳輸速率下降但傳輸距離

52、增加了，最長可至7Km，提高了覆蓋范圍，定位于Inter接入，主要支持IP業(yè)務。第六章13.HFC的組成和結構是怎樣的HFC網(wǎng)絡面臨哪些問題？答：P99；上行信道噪聲問題，可靠性問題，安全性，以及操作、管理和維護等方面問題。14.CM接入采用什么帶寬分配機制？如何進行帶寬分配？答：發(fā)送器使用5MHz~42MHz上行信道，將用戶發(fā)向頭端信息調制到該頻段的某個6MHz寬的頻道內發(fā)送，而其接收器除了能調諧出模擬電視信號，還要在450MHz~7

53、50MHz頻帶范圍內解調出數(shù)字信息。，一般在上行信道使用正交相移鍵控，在下行信道使用正交振幅調制。第七章15.無線接入技術的特點有哪些？答：無線接入的靈活、方便、快捷、不受線纜約束，但是速率慢、不穩(wěn)定、信號差，比較昂貴。16.目前有哪些無線接入技術，各自的特點是什么（P122）答：①WLAN，一種是用無線傳輸?shù)木钟蚓W(wǎng)技術，網(wǎng)絡覆蓋半徑約為100m，工作在2.4GHz和5GHz頻段。②WMAN，一種城域接入網(wǎng)絡，覆蓋半徑為10km到幾十k