程控交换复习题SPC exchange review.docx

程控交换复习题SPC exchange review.docx

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程控交换复习题SPCexchangereview

程控交换复习题1（SPCexchangereview1）

SPCexchangereview

I.simplequestions

Chapter1

1.Whatisacommunicationnetwork?

Whatarethethreepartsofit?

Itconsistsofuserterminalequipment,transmissionequipmentandswitchingequipment.Itiscompletedbytheexchangedevice,sothatanyuserinthenetworkcancommunicatewithotherusers.

2,realizethethreeelementsofcommunication

Terminal,transmissionandswitching.

3.Whatisatelephoneexchange?

Telephoneswitchingisthemostbasicswitchingserviceintelecommunication.Itreferstotheinformationofanycallinguser,whichcanbesenttoanydesiredormorecalledusersthroughtheswitchingnodesinthecommunicationnetwork.

4.Whatarethe2typesofsignalstransmittedinacommunicationnetwork?

Analogsignalsanddigitalsignals

5,analogswitchesbasicworkingprinciple?

Theswitchingfunctionofthenetworkisaccomplishedbythecrosscontactmatrix,andthecontrolpartoftheswitchcontrolsthedisconnectionandclosingofthenodesinthecontrolmatrixsoastocompletetheconnectionoftheinputlineandtheoutputline.

6,thebasicworkingprincipleofdigitalswitches?

Indigitalswitches,thetransmissionofthemessagechannelisthepulsecodemodulation（PCM）signal,andtheswitchingnetworkadoptsthedigitalswitchingnetworkDSN.Digitalswitchesgenerallyreferstodigitalprogram-controlledswitches,theswitchingnetworkusedmainlybytheelectronicswitcharraycomposedofspacedivisionandtimedivisionswitchingnetwork,composedofmemorycircuitswitchingnetwork,areexchangedforspaceandtimedivision.

7.Classificationofswitchingtechnologies

（1）analogtransmissionanddigitalswitchingintheformoftransmissionsignals.

（2）accordingtotheaccesscontrolmethod:

controlexchangeandexchangeprogram.

（3）dividedintocircuitswitchingandpacketswitchingintheformoftransmissionchanneloccupancy.

（4）accordingtothetransmissionbandwidth:

narrowbandswitchingandbroadbandswitching.

8,whatisthedifferencebetweencircuitswitchingandpacketswitching?

Circuitswitchingisakindofreal-timeexchange.Theuserestablishestheconnectionbycalling,andtheswitchingsystemallocatessomebandwidthtobothsidesofthecommunication.Whenthecommunicationisfinished,theresourceisreleasedandtheconnectionisremoved.

Thestoreandforwardpacketswitchingprinciple",theuserinformationwillbedividedintoseveralgroups（packet）exchangeandtransmission,eachpacketcontainsapacketheaderinformationanddomain2parts,packetswitchingnoderoutingaccordingtotheroutinginformationofthepacketheader,tocompletetheexchangeandtransfer.

9,whatarethe2formsofpacketswitching?

Whatistheirprinciple?

Packetswitchingconsistsof2formsofvirtualcircuitanddatagram.

Eachvirtualcircuitservicethroughthecallpacketestablishingalogicalconnection（virtualcircuit）,packetdeliveryservicetoallinthevirtualcircuitestablishment,eachpacketisnotexclusivetothephysicalline,butstillistheexchangeofvirtualcircuitconnectionoriented.Thedatagramisorientedexchangeconnection,whereineachpacketheadertocarrywiththeroutinginformation,exchangenodesexchangeandtransferthroughtheanalysisofeachroutinginformationpacketheader,allpacketsofthesameservicemaybealongdifferentpathstoreachtheendpoint.

10,whatarethe3typesofsubscriberlinesignaling?

Userstatussignaling（monitoringsignal）,selectivesignaling（addresssignaling）,signalingtothesubscriber.

11,whentheuser'sphoneisoffthehook,theDCloopresistanceusersabout1.8K.Whentheuserisonthehangstate,theresistancebetweentheuser'slinesisgreaterthan20k.

12,whatarethe4userstatussignaling?

（1）（calleroffhook）takebreath;

（2）response（calleduserhook）;

（3）forwarddisconnect（callingsubscriberhangup）;

（4）backwardstitches（calledsubscriber）.

13.Listthesignaltonesissuedbythe3switchestotheuser:

Busytone,dialtone,ringbacktone.

14,thereare2sourcesofsignaltonefrequency:

450Hzand950Hz.

15.China'sNo.1signalingisdividedintolinesignalingandregistersignaling.

16,Chinaline1signalingcanbedividedintoDClinesignaling,inbandsinglefrequencylinesignalinganddigitallinesignaling.

17,inlinesignaling,whataretheprovisionsofthecompulsoryrelease?

GBhooklongdial:

10s,waitingforalongtime,longwaitingforalongtimewithoutdialing20s,responsemonitoringlong-distancecall90s.

18,inthe30/32roadPCMsystem,eachcomplexframehas16frames.Eachframehas32timeslots,30timeslotstransmitvoicesignals,theTS0slottransmitsframesynchronizationsignals,andtheTS16slottransmitsthelinesignalingofthespeechchannel.

19,accordingtoITUrecommendations,PCMcodesamplingfrequencyis8000HZ,PCMbasegroupmultiplexingrateis2.048Mb/s.

20,NO.7signalingsystemusesthefunctionofmodularstructure,whichmainlyinclude3parts?

Themessagepassingsection（MTP）,thesignalingconnectioncontrolsection（SCCP）,andtheuserpart（up）.

21,whatarethethreefunctionallevelsofthemessagingpart?

Signalingdatalinkfunction（MTP1）,signalinglinkfunction（MTP2）,signalingnetworkfunction（MTP3）.

22,NO.

Whatarethethreesignalingcellformatsforthe7signaling?

Themessagesignalingunit（MSU）,thelinkstatesignalingunit（LSSU）andthefillsignalingunit（FISU）.

Whatarethethreepartsofthe23andNO.7signalingnetworks?

SignalingpointSP,signalingtransferpointSTP,signalinglink.

24,whatarethethreelevelsoftheNO.7signalingnetworkinChina?

Adopt3levelsofstructure:

HSTP（Advanced）,LSTP（lowerlevel）andSP（signalingpoint）.

25.Thetransmissionrateofdigitalsignalingdatalinkis64Kb/s,andthetransmissionrateofanalogsignalingdatalinkis4.8Kb/s.

26.Thestartingandendingflagsusedbythesignalingunitdelimitationareasfollows:

01111110.

27.Designthebasicsignalingprocessbetween2localtelephonestationsusingChinaNo.1signalingforcallconnection.

28.DesignthesignalingprocessoftheAswitchingboardusercallingtheBswitchingofficeuser'slocalcallconnectionwithCCITT7signaling.

Secondchapters

Whatarethe2partsofthe1andTwiringdevices?

Whatareitsmainfunctions?

TheTconnectioniscomposedofavoicememoryandcontrolmemoryiscomposedoftwoparts,itsfunctionistocompletetheexchangeofinformationwiththetimeslotinterchange,abusindifferenttimeslots,thatisalineinatimedivisionmultiplexingtimeslotinformationexchangetoanothertimeslot.

2,Stypewiringdeviceworkingprinciple?

TheStypeconnectorconsistsofM*ncrosspointmatrixandcontrolmemory.ThereisanintersectionpointJbetweeneachincominglineIandtheoutgoingKij.Whenanintersectionisconnectedunderthecontrolmemorycontrol,thecorrespondinginputlinecanbeconnectedwiththecorrespondingline.

3,homeworkP54,16,17,18,19questions.

Thirdchapters

1,whatarethe4partsofthehardwarepartoftheprogramcontrolledswitch?

Messagesection,controlsection,operationsystemandmaintenancesection.

2、themainfunctionofanalogusercircuit

Feeding,overvoltageprotection,ringingcontrol,monitoring,codinganddecoding,filtering,mixingcircuits,testing.

3、feedingtotheuserphoneispoweredbytheDCpowersupplyof-48V.

4,theuserhubusuallywith120usersfor1groups,outgoinglinefor4setsofPCMline.

5,whengeneratingasignaltone,howmanyunitsof500MHztonedoesthe450MHZneed,andhowmanyunitsofROMmemoryareneededfortheROM?

;

6,theprogram-controlledswitchcontrolsystemcangenerallybedividedintowhichthreelevels?

Thefirstlevelisthetelephoneperipheralcontrollevel.

Levelsecondisthecallprocessingcontrollevel.

Levelthirdisthemaintenancetestlevel.

7.Whatarethethreemodesofworkinadualprocessorarchitecture?

Synchronousduplexoperation,trafficsharing,workmodeandmain/standbymode.

8.Brieflydescribetheworkingprincipleofthemain/standbymode

Twoprocessorsinthisway,oneforthemainandtheotherforthestandby.Whenthemainmachinefails,thestandbymachinewillreplacethemainmachine.Therearetwostandbymodes,namelycoldstandbyandhotstandby.

Fourthchapters

1,whatarethe3typesofSPCswitchingsystems?

Systemdata,officedata,anduserdata.

2,callhandling8processes?

1）callinghook,2）dialtone,3）receivingthenumber4,number5）throughanalysis）,called6）,ringing,7）calledresponseandcall,8）endup

3,useranswersidentificationscanningcycle200ms,dialpulserecognitionscancycleis8ms,intervalidentificationscanningcyclewas96ms.

4,assumingthattheuserbasefor32users,using8086assemblyorClanguagedesigngroupprocessing,pick,hangprogram.

5.Designthebitintervalidentificationprogramin8086assemblerorClanguage.

Fifthchapters

1.Themobilecommunicationsystemisusuallycomposedofmobilestation（MS）,basestation（BS）andmobileswitchingcenter（MSC）

2,themainfunctionsofthebasestation:

Itisresponsibleforradiofrequencysignaltransmission,receptionandwirelesssignalaccesstotheMSC,andalsohaschanneldistribution,signalingconversion,wirelesscellmanagementandothercontrolfunctions,usuallyaBScontrolofawirelesscell.

3、themainfunctionofmobileswitchingcenter

ThecompletionofthisMSCcontrolofmobileusersintheregionofcommunicationcontrolandmanagement,includingalltypesofmobilecallcontrol;throughastandardinterfaceconnectedwiththebasestation（BS）andotherMSC,switching,roamingandbilling