BeijingBeijingCredit OPNETModelerTraining(Day4)CourseCourseDAYModelingFeaturesoftheProjectEditor{Lab}NodeModelingProcessModelingOtherEditorsRunningTheUnderstandingConfigure/RunSimulationDAYGeneralSimulationEventsandEventListProcessModelingMethodologyParametricDAYTrafficModelingApplicationswiththeStandardApplicationModelsDebuggingTechniquesDAYWirelessModelingEffects{Labs}TerrainModelingCosimwithViewingSimulationPublishingandBuildingaFirstNetwork2BeijingCreditTopCo.,.AllBeijingBeijingCredit WirelessWirelessModelingWirelessWirelesslinksarelessreliablethanwiredNeedtocharacterizewirelesschannels Modelreal-worldchannelFrequencies,power,pathloss,line-of-sight,interference,Channelcharacteristicsaffecthigher-layerprotocolRetransmissionAdaptiveAdaptiveScheduling/allocationofradioSpecialrequirementsforthesimulationTerrain4BeijingCreditTopCo.,.AllWirelessWirelessWirelessisabroadcasttechnologyanddependsondynamicallychangingparameters.Thesimulationmustevaluatethepossibleconnectivitybetweenatransmitterchannelandeveryreceiverchannelforeachtransmission.Thenetworklevelcharacteristicsfactoredintothesecalculationsarethelocationsofthesourceanddestinationnodes,thedistancebetweenthenodes,andthedirectionthewirelesssignaltravelsfromthesourcenodetothedestinationnode.Awirelesslinkcanexistbetweenanyradiotransmitter-receiverchannelpairandisdynamicallyestablishedduringsimulation.5BeijingCreditTopCo.,.AllWirelessWirelessAwirelesslinkisnotstaticallyrepresentedbyanobject,asarepoint-to-pointandbuslinks.Awirelesslinkcanexistbetweenanyradiotransmitter-receiverchannelpairandisdynamicallyestablishedduringsimulation.Thepossibilityofawirelesslinkbetweenatransmitterchannelandareceiverchanneldependsonmanyphysicalcharacteristicsofthecomponentsinvolved,aswellastime-varyingparameters,whicharemodeledintheTransceiverPipelineStages.6BeijingCreditTopCo.,.AllWirelessWirelessTransmissionTransmitter–ExecutestransmissionactionsaccordingtoitsofbitstransmittedtimeallocationReceiverExecutesreceptionitsdefinedReal OPNETradio7BeijingCreditTopCo.,.AllRadioRadioRadioModulesinaNodeRadioRadio8BeijingCreditTopCo.,.Allisspecifiedintheantenna–Data–Packet–Min–Spreading–Bitcapacity(Tx–Packetcapacity(Tx–AssociatesthemodulationtablePipeline–DifferentsetsforTxand9BeijingCreditTopCo.,.AllTransceiverTransceiverModelsthetransmissionofpacketsacrossImplementsthe“physicallayer”Dividedintomultiplestages,eachmodelingaparticularaspectofthechannelDetermineswhetherornotapacketcanbereceivedatthelink’sdestinationthelink’sbehaviorBeijingCreditTopCo.,.AllRadioTransceiverAttributesforRadioTransceiverAttributesforSpecifyingPipelineStagesRadioRadiowithRadiowithRadioReceiverBeijingCreditTopCo.,.AllRxAntennaReceivedBitErrorErrorErrorReceiverLinkClosureChannelTxAntennaRadioRadioTransmitterandReceiverModulation-nameofmodulationtableusedtolookupthebiterrorrate(BER)asafunctionofeffectivesignaltonoiseratioChannel-specifiesthenumberandattributesofthechannelsinthetransceiverNoisefigure-representstheeffectofthermalnoiseonwirelesstransmission(receiveronly)Eccthreshold(err/bits)-specifiesthehighestproportionofbiterrorsallowedinapacketinorderforthepackettobeacceptedbyareceiver(receiveronly)...model-theseattributesspecifythevariousTransceiverPipelineStagemodelsusedBeijingCreditTopCo.,.AllWirelessWirelessChannelDatarate(bps)-rateatwhichdatamaybetransmittedorPacketformats-determinesthetypesofpacketsachannelcantransmitorreceiveBandwidth(KHz)-specifiesbandwidthofMinfrequency(MHz)-specifiesthebasefrequencyoftheSpreadingcode-usedtospecifyauser-assignedcodeforthePower(W)-transmissionpowerofpacketstransmittedthroughthischannel(transmitteronly)BeijingCreditTopCo.,.All nodesmodelterrestrialnetworkelementswhosepositionsvarywithtime,suchasauto s,aircraft,and nodescannotbeconnectedtopoint-to-pointandbuslinks,becausetheymoverelativetotheearth.nodesmaychangepositionduringa–AnAssigned–Random–DirectlyChangingNode’sPositionBeijingCreditTopCo.,.AllNodeNodeAtrajectoryisthepathanodemovesalongTrajectoriescanbecreatedusingthe“DefineTrajectory”selectioninthe“Topology”pulldown Duringsimulation,the nodefollowsthetrajectorybytravelinginastraightlinefromonedefinedpositiontotheOncethesimulationtimeexceedsthelastspecifiedtimeinthetrajectoryfile,the noderemainsatitsfinalposition.BeijingCreditTopCo.,.AllDefiningDefiningaattributestothedesiredvalues.5.Left-clickintheworkspaceto4.Left-clickatsomeEditortobeginthe nodessupportanattributecalledtrajectorywhichspecifiesthenameofanASCIItextfiledefiningthepathofthenodeduringtheBeijingCreditTopCo.,.All3.ClickonDefine1.ChooseDefineTrajectoryfromTrajectoriesTrajectoriesforNodeTrajectoriesdefinethepathofnodeduringsimulationinatextfileofaspecificformatNew:preferencecontrolsthe yoftrajectoriesintheTwo–Withabsolute–Withpositionsrelativetonode’sstartingAttributesofapositionentryinatrajectoryXYWaitTimeBeijingCreditTopCo.,.AllModelingModelingNodeThreemethodstoenablenode–Modifyingnodeposition tically,e.g.“Random–Specifyinga“motionvector”viaBeijingCreditTopCo.,.AllRandomRandomWaypointNodemovesrandomlyfromonewaypointto–Modulerandomlychooseslocationofeachwaypointwithinspecifiedrectangle–SpeedbetweenwaypointsandpausetimeatawaypointfollowspecifiedrandomdistributionsConfigureusingRandomWaypoint“utility”–Specifyrectangularregionviacoordinatesorgraphicallyusingthe“wireless s”object–Definerandomwaypointprofilesbyspecifyingspeed,starttime,stoptime,andpausetime–GUIsupportforassigningprofilestoaset TrajectoryBeijingCreditTopCo.,.AllMobilityMobilityop_ima_obj_pos_query_proc_setkernelcallsauser-definedprocedurewhenitneedstoaccessanode’slocationCannotusewithnodesassignedtoop_ima_obj_pos_notification_registerAbilitytoperformanyprocessing/protocol-relatedfunctionsuponnotificationfromthekernelthatthenodepositionisbeingevaluatedbythekernel–op_ima_obj_pos_get–op_ima_obj_pos_set_geocentricSetsthepositionofa siteinthegeocentriccoordinate–op_ima_obj_pos_set_geodeticSetsthepositionof siteinthegeodeticcoordinateBeijingCreditTopCo.,.Alllite litenodesmodelnetworkelementsinorbitaroundtheearth,suchassa litesandspacecraft.nodes, litenodescannotbeconnectedpoint-to-pointandbuslinksbecausetheychangepositionsduringasimulation. litenodeschangepositionbasedonanassignedorbitorbydirectchangestothenode’spositionattributes.BeijingCreditTopCo.,.AllOrbitscanbeimportedfromSTKandviewedusingop_vuorb(shownbelow)BeijingCreditTopCo.,.AllWirelessWireless–DynamicReceiver–Parallel Add-on–TMM:(TerrainModelingTheTerrainModelingModuleallowsyoutotakeintoaccountterrainwhenmodelingwirelessnetworks.WithTMM,youcanimportelevationmapsthatcontainterrainSupportedmapformatsareDTEDandTMMalsoallowsyoutoselectandcomparesignallossfromvariouspropagationmodels.RequiresWireless–TIREM(TIREMpropagationAddstheabilitytousetheTIREMpropagationcalculationsinadditionthebuilt- SpaceandLongley-Ricepropagation RequiresWirelessandTMM BeijingCreditTopCo.,.AllLab:Lab:WirelessThislabwillmodelpagingBeijingCreditTopCo.,.AllLab:Lab: ephonesinitiatepagesaddressedtoa–Thepagesarerelayedthroughacentralbase–Aradiotowerbroadcaststhe–Iftheappropriate pagerreceivesthepage,anackistransmittedbacktotheradiotower.–TheradiotowerrelaystheackbacktothebasestationandsuccessfulpagestatisticisBeijingCreditTopCo.,.AllWirelessmodelsdependondynamicallychangingparameters,which thesimulationevaluatestodeterminethepossibleconnectivitybetweenallradiotransmittersandreceivers.Modelersimulatethemovementoftrajectoriesandsa litenodesinorbit.nodesTheantenna,PDF,linkandpacketeditorsfurtherexpandsyourcapabilitytodefineandcustomizeparametersthataffectthebehaviorofthemodel.BeijingCreditTopCo.,.AllBeijingCreditTopCo.,.AllBeijingBeijingCredit WirelessEffectsEachEachstagemodelsanaspectofthechannel’s .. OPNETTransceiver“Pipeline”usedtodenotesequenceofModeling–Whateffectwillthetransmissionhaveonnodesinthe–Whichsetofnodeswillattempttoreceivethe–Willanodeattemptingtoreceiveapacketsuccessfullydo–HowlongwillittakeforapackettobetransferredtotheBeijingCreditTopCo.,.All112Point-to-PointPipelineExecutionforone4BeijingCreditTopCo.,.AllAllocationBusBusPipelineExecutionsequenceforonestages2andupareexecutedseparayforeach1stage1executedonceper23 multiple4collisionstagemaybeexecutedzeroormoretimesBeijingCreditTopCo.,.AllRadioRadioPipelineModelTheycannotbepromotedtotheprojecteditor;youmustconfigureandsavetheminthenodemodelRadioRadio6stages(0–5) withRadio withRadioBeijingCreditTopCo.,.AllRxAntennaReceivedInterferenceBackgroundSignal-to-NoiseBitErrorErrorErrorReceiverTransmissionLinkChannelTxAntennaPropagation GRadioRadioPipelineStages(Transmitter0channelsordynamicallybyKernelProcedurecalls1CopyCopyTx2345…CopyClosurefails:droppacketMatchIGNORE:dropX23separayforeachreceiverchannelinreceivergroup45Closurefails:droppacketMatchIGNORE:droppacket(onthenextBeijingCreditTopCo.,.AllStartofRadioRadioPipelineStages(ReceiverForeveryreceiverchannelwhich“passed”thetransmission678912130+:Executedzeroormore1+:Executedoneormore BeijingCreditTopCo.,.AllEndofforVALIDEndofStartofTransmissionDataAttributesSpecialpacketstoragePartofeveryCarrynumericalInteger,ObjectID,floatingpoint,orInitializedbykernelatstartofReadableduringapacket’sWritableonlyinConveylinkFromkerneltopipelineFrompipelinestagetoBetweenpipelineBeijingCreditTopCo.,.AllUserDefinedPre-DefinedRadioRadioPipelineSequenceof“C”or“C++”EachstageperformsadifferentBiterrorsps.c/ps.cppfileEachprocedurehasadefinedinterface(prototype)ArgumentistypicallyayoucanassignapipelinestageviatheradiotransmitterorreceivermoduleattributesBeijingCreditTopCo.,.AllDefaultDefaultPipeline-StageDefault(e.g.,“C:\ProgramFiles\OPNET\<OPNETDefaultstage–dpt_*-defaultpoint-to-–dbu_*-default–dra_*-defaultToopen:“File|Open|PipelineStage[pull ]”&NOTE:OPNETcanaccesspipelinestagesfromanypathinBeijingCreditTopCo.,.AllPipelinePipelineStageFile–<name>.ps.c-C–<name>.ps.cpp-C++Procedure–Either<file_name>or–Byconvention,use_mtifmulti-threading–Filemayhaveother“helper”functionsorcallfunctionsdefinedinexternal–Compile –op_mko-typeps-m NOTE:Whenconfiguringtransceiverattributesthechoicesforpipelinestagesaretakenfromthesetof.ps.ofileslocatedinmod_dirs.BeijingCreditTopCo.,.AllAssigningAssigningPipelineStagetoOncecreateandcompiled,youcanassignapipelinestagetoamoduleviatheradiotransmitterorreceiverobjectTheradiotransmitterandreceivermoduleshaveanattributeforeachstageofthewirelesstransceiverBeijingCreditTopCo.,.AllStageStage0:ReceiverThisprovidesamodelaccelerationReducecomputationtotheminimumrequiredFilteroutineligiblereceiverSimulationruntimePossibleDisjointfrequencyExcessivephysicalAntennaOnceatstartofsimulation,RxRxRxRxRxRx– Rx–Definesdestinationchannelsetforeachtransmitting BeijingCreditTopCo.,.AllStage0:ReceiverGroup–Nocomputationforreceiver–ItisMT-safe(appliestoallstatesendingwith–InitializesobjectstatetostoresignalTheKPop_ima_obj_attr_get()ismoreexpensiveFor“fixed”wirelessnodesperformEarth-Line-of-SightAddonlyreceiversusingthesameradioIgnorereceiversaftercertain–AllreceiversarepotentialReturnsVersionwithoutobjectBeijingCreditTopCo.,.AllReceiverReceiverGroupAprocesscanmodifyachannel’sreceivergroupatanytimeduringasimulation(“dynamicreceivergroups”)—anefficiencytechniqueputefrom–Recalculatethereceivergroupusingapipeline-stagestyle–UsetheKernel pute(txch_objid,pipelinestageDirectlyaccessorassignentire–op_radio_txch_rxgroup_get(txch_objid,count_ptr,Getthereceivergroupofatransmitter–op_radio_txch_rxgroup_set(txch_objid,count,SetthereceivergroupofatransmitterchanneltoaspecifiedarrayofobjectBeijingCreditTopCo.,.AllReceiverReceiverGroupModification–Startwithanemptysetandaddchannelsoneafter–Startwithallpossiblechannelsinthesetanddelete–op_radio_txch_rxch_add(txch_objid,AddthespecifiedreceiverchanneltothereceivergroupofthespecifiedtransmitterchannelAllowaddingachanneltoallreceivergroupswithtxch_objidsetto–op_radio_txch_rxch_remove(txch_objid,RemovethespecifiedreceiverchannelfromthereceivergroupofthetransmitterchannelAllowremovingachannelfromallreceivergroupswithtxch_objidsettoBeijingCreditTopCo.,.AllBroadcastBroadcastPropertyofSpecialpropertyofeachpacket-“BroadcastMustsetusingKPop_pk_bcast_unique(packetpointer,node[RequiresprocessoOnlynodewithIDnodeidreceivestheNOTE:AlleligiblereceiverchannelsinnodewithIDnodeidreceiveNOTE:PacketmuststillbesenttothetransmittermoduleorDefaultAlleligiblereceiversreceivethe“Unique”canberesetto“general”byBeijingCreditTopCo.,.AllReceiverReceiverGroupConfigProvideswaytoconfigurerxgroupsinaconfigobjectratherthanprogrtically(i.e.insourcecode)Can–Towhichtransmittersit–Durationandexecution–Howitevaluatesreceiverchannelsto membersofitsrxgroupBeijingCreditTopCo.,.AllVisualizationVisualizationTxPacketsUsingDrawslinesconnectingtransmitterstoallreceiversintherxgroupwhenthetransmissionstarts&removesthemuponreceptionontheparticularreceiver’sendDrawspulsatingcirclesaroundthetransmittingnodewhentransmissionstarts&removesthemwhenthetransmissionendsDrawspacketflowsalongastraightlinebetweenthetransmitter&receiver–Firsthalftraversedwhentransmission–SecondhalftraversedwhenreceptionUsesvaryingcolorsuniquetoasingleChangespacketicontovariationwithredXforfailedreception&packettitletonameoffailedstage BeijingCreditTopCo.,.AllLabLab:IntroductiontoRadioPipeline–Modifythereceivergroups–Visualizetheradiopackettransmissionsusinginthemanual partIIIforBeijingCreditTopCo.,.AllStageStage1:Transmission–Computestimerequiredtotransmit–Firstdynamic–Startofpacket–Singleinvocationforalldestination–Packet–SetsTX_DELAY–Kernelschedulesend-of-transmission–SignalsstartoftransmissionofnextpacketintransmitterBeijingCreditTopCo.,.AllTxTxTxStage1:TransmissionDelay –Basedonchanneldatarateandpacket–Datarate(bits/sec)fromTX_DRATE–Packetlength(bits)from cescomputeddelayvalueinTX_DELAYBeijingCreditTopCo.,.AllDelayPacketDataStageStage2:DetermineswhethersignalcanreachAllowsdynamicenabling/disablingofOnceforeachdestinationCalled yafterstage1–nointerveningPacketSetsPROP_CLOSUREIfocclusion(obstruction)occurs,nofurtherstagesarecalledforthepacketBeijingCreditTopCo.,.AllStageStage2:ClosureFirst,checkifterrain(TMM)modelingmoduleisIfnoBasedonray-tracingline-of-sightAssumesearthissphericalbyThreeocclusionCase1:Case2:90o,<Case3:90o,dearthEllipsoidearthmodelCase<TDD<RTR>Case–Applyphysicalobject(e.g.,buildings)occlusionwithacustomrepresentationoftheobjectsandtheirpositionsIfanycasefails,occlusionPROP_CLOSUREsettoCase<Dd>TR Case BeijingCreditTopCo.,.AllStageStage3:ChannelClassifiestheTypicallybasedonfrequency,bandwidth,datarate,spreadingcode,modulation,etc.OnceforeachdestinationchannelsatisfyingstageCalled yafterstage2–nointerveningPacketSetsMATCH_STATUSValid,noise,orIfignore,nofurtherstagesarecalledforthe BeijingCreditTopCo.,.AllStageStage3:ChannelMatch–Accountsforfrequencyoverlap,datarate,modulation,andspreadingcode–ThreeCase1:Nofrequencyoverlap–Case2:Partialcharacteristicsmatch–Case3:Fullcharacteristicsmatch–PacketssendinmulticarriersystemsmayrequirespecificationofdiscontinuoussubcarrierPacketsmayuseapartialfrequencyofthereceiverchannelandstillneedtobevalidpackets–SetsMATCH_STATUSTDAbasedonCaseCaseCaseBeijingCreditTopCo.,.AllFTxFRxDRTxDRRxFTxFRxDRTxDRRxFTxStageStage4:TransmitterAntenna–Computestransmitterantennagaininthedirectionofthe–Onceforeachdestinationchannelsatisfyingstages2and–Called yafterstage3–nointervening–Packet–SetsTX_GAIN–Typicallyusedbystage7forreceivedpowerBeijingCreditTopCo.,.AllStageStage4:TransmitterAntennaGain–Alignsallentitiesw.r.t.samecoordinate–DistancevectorbetweenTxand–Antennapatternsandnodelocations–DeterminesdirectiontotheRx(2look-up–Performstablelook-uptoobtaingainGainsvaluescouldbeobtaineddirectlyfromothersources,e.g.,attributes cedinTX_GAINforusebystageCoordinate–Right-handed(default)andleft-handed–SupportforellipsoidEarth–Right-handedsphericalbydefault,setgeocentric_modelBeijingCreditTopCo.,.AllGainStageStage5:PropagationCalculatessignalpropagationtimefromtransmittertoUsuallydependentondistanceandpropagationOnceforeachdestinationCalled yafterstage4–nointerveningPacketSetsSTART_PROPDELandEND_PROPDELKernelStartofreception Endofreception BeijingCreditTopCo.,.AllStageStage5:PropagationDelayBasedondistanceandpropagationComputedforstartandendofTakesintoaccountObtainsdistances(in–Customization:Assumezeropropagationdelaytoaccountfortimesynchronizationwithinacell(e.g.,forTDMAbased –Kernelschedulesstartandendreception BeijingCreditTopCo.,.All Rx RxDelayStageStage6:ReceiverAntennaGain–Alignsallentitiesw.r.t.samecoordinate–DistancevectorbetweenRxand–Antennapatternsandnodelocations–DeterminesdirectiontotheTx(2look-up–Performstablelook-uptoobtaingainGainsvaluescouldbeobtaineddirectlyfromothersources,e.g.,attributes cedinRX_GAINforusebystage7BeijingCreditTopCo.,.AllGainStageStage7:ReceivedComputessignalpowerlevelatTypicallybasedontransmitterpowerandfrequency,distance,andantennagainsComputedonlyforvalidandnoiseOnceforeachdestinationCalled yafterstage6–nointerveningPacketSetsRCVD_POWER–Kernelusesvaluetorecordreceiverpowerchannel BeijingCreditTopCo.,.AllStage7:ReceiverPower–DeterminesifsignallockisUsesRx–ObtainsRxandRxantenna–Computespathloss– LPathLp 4D DCSpeedof fCenterPInband PTransmittedPowerf umFrequencyPPtxfmaxfmin fMinimumFrequencyB PReceivedPowerGTransmitterAntennaGain GReceiverAntennaGainorobtainsvaluecomputedbyintheclosurePathlossmodelcomputationcanbeeasily–Valuecedin–ValidpacketsevaluatedwhenRxislockedareswitchedto BeijingCreditTopCo.,.All12Signal–Attributeofeachdestination–Providesabilityforreceivertolockontoarrivingpacket–FirstvalidpacketarrivalatdestinationSignallock–SubsequentvalidpacketMatchstatuschangedto–FirstvalidpacketcompletesSignallock–Signallock–Channelobject12BeijingCreditTopCo.,.AllLabLab:ClosureApplyclosurePleaseworkthroughLabinthelabmanualBeijingCreditTopCo.,.AllInterferenceInterferenceNoisedetermineschangesininterferencenoiselevelsSNRcomputationperformedlaterbystage10foreachUponpacketcompletion,kernelsubtractsnoisepowerofcompletingVariationsininterferencereceivedVariationsininterferencereceivedVV12321tVariationsininterferencereceivedtV12324N BeijingCreditTopCo.,.AllStageStage8:InterferenceAccountsforconcurrentComputestheeffectofinterferencenoiseonvalidOnlyifpacketcollisionSetsNOISE_ACCUMSetsNUM_COLLSPacketpointersofarrivingpacketandpacketalreadybeingAccumulatesnoiseofinterferingNoisefrompacketcompletingreceptionissubtractedbyTypicallyusedinstage10forsignal-to-noiseratioBeijingCreditTopCo.,.All12341StageStage8:InterferenceNoise–Collisiondefinedbytimeoverlap(channelmatchdeterminedearlierthefrequencyoverlap)–Incrementscollision–Addsreceivedpowerofcolliding–ObtainspowerfromRCVD_POWERcesaccumulatednoiseinNOISEValueusedinstage10insignal-to-noise Resultofcollisioncanberedefinedaswell:e.g.,twoCDMAcodescollidingactuallyadduptogetherandcontinueasasinglesignal(i.e.,packet)BeijingCreditTopCo.,.AllStageStage9:BackgroundRepresentseffectsofallbackgroundnoiseTypicallyThermalorgalacticEmissionsfromnearbyelectronicOtherun-modeledradioCalled yafterstage8–nointerveningPacketSetsBKGNOISE–Typicallyusedbystage10insignal-to-noise BeijingCreditTopCo.,.AllStageStage9:BackgroundNoise–Constantambient–Constantbackground–ConstantthermalRadioReceiver cedinBKGNOISEforusebystage10insignal-to-noise Trx(NF1.0)*290.0TbkkNTTBNFNoiseTReceiverTBackgroundkBoltzmann'sBReceiver B NBackgroundNNNAmbientN BeijingCreditTopCo.,.All123Stage10:Signal-to-Noise–Computesthecurrentaverage–TypicallybasedonreceivedpowerandInvocation(onlyforvalid–Operatesonvalidpackets–thoseinvalid–Doesnotrequirecollisionfor–“Startofpacket–Packet–SetsSNR–UsedbykerneltoupdatereceiverchannelInvokedInvokedmultiple–Usedbylater BeijingCreditTopCo.,.AllStage10:Signal-to-NoiseRatio–ObtainsreceivedpowerfromRCVD_POWERComputedinstage–ObtainsinterferencenoisefromNOISE_ACCUMComputedinstage–ObtainsbackgroundnoisefromComputedinstage–Computessignal-to-noiseratio(inSNR10log10Pr/(PbPiPrReceivedPower(watts)PbBackgroundNoise(watts)PiInterferenceNoiseMultipatheffectcanbeappliedtothedefaultSNRRepetitioncodingSNRgaincanbeappliedas cesinSNR–Valueusedinstage11inbit-error-rate BeijingCreditTopCo.,.All123Stage11:BitErrorDerivestheprobabilityofbitComputedforeachpacketsegment–constantValuetypicallyobtainedfrommodulationOperatesonvalidpackets–thoseinvalidDoesnotrequirecollisionfor“EndofpacketPacketSetsBERUsedbythekerneltorecordBERTypicallyusedinstage12forallocatingInvokedInvokedmultipleBeijingCreditTopCo.,.AllStageStage12:Error–Estimatesbiterrorsforeachpacket–Called yafterstage11–nointervening–Setsbit-erroraccumulationinNUM_ERRORS–SetsempiricalbiterrorrateinACTUAL_BER–Packet–Kernelmaintainsabitaccumulator–NUM_ERRORS–KernelupdatesBERstatistic–ACTUAL_BER–Typicallyusedinstage13forerrorBeijingCreditTopCo.,.AllStageStage11:BitErrorRateObtainssignal-to-noiseratiofromSNRComputedinstageObtainsprocessinggainfromPROC_GAINAttributeofreceiverComputeseffectiveDeterminesexpectedbit-error-Modulationtablelook-ApplyBLERinsteadofApplyconstantBER/BLER(e.g.,disregardSNRResult:RecordsBERTDAforuseinstage12inerrorallocationcomputationKeykernel–op_tbl_mod_ber–op_tbl_modulation_get()BeijingCreditTopCo..AllGpProcessingPPpk(1p)NkNkkPkNkPProbabilityofkErrorspProbabilityofErrorNPacketLength(bits)rop_dist_kNumberofStageStage12:ErrorAllocation–Doesnotperformbit-by-biterrorCannotretainbit-error–Obtainsprobabilityoferror–BER–Computesprobabilityofk–Generatesuniformrandomnumber:r=(0–Integratesprobabilitymassover –EfficiencyNeednotintegratetillexactnumberoferrorsisStopcomputationifnumberoferrorexceedsAssumezeroerrorsforCDMAcode–RecordsNUM_ERRORSVersionwithexactnumberoferrors BeijingCreditTopCo.,.AllStageStage13:ErrorDeterminesacceptabilityoftheentirearrivingOnceforeachvalidCalled yafterstage12–nointerveningSetsPK_ACCEPTPacketDestroyedbyForwardedonoutputBeijingCreditTopCo.,.All%%NPStage13:ErrorCorrection RadioReceiver–ObtainsthresholdfromECC_TRESHPercentageofpacketbitsinerrorthatstillyieldsacceptabilityDefault:acceptsonlyif0%–Obtainspacketlength–Obtainsnumberoferrorsfrom–Computesthepercentthresholdand–Releasessignallock–usesobjectVersionwithoutobject–PacketacceptedorrejecteddependingBeijingCreditTopCo.,.AllPipeline“Skip”apipelinestagecanspeedupsimulationsinnetworkswithlargenumbersoftransceiverchannelsSetthepipelinestageattributetoNONE—thepipelineskipsthecomputationandusesafixedpre-determinedvalueastheresultofthecomputation–Example1:NONEforrxgroupmodelcreatesemptyreceivergroupsforalltransmitterchannels–Example2:NONEfortxdelmodelassignsatransmissiondelayof0secondstoalltransmissionsYoucanchangethedefaultvalueassignedbytheNONEpipelinestageviasimulationpreferences–CannotmodifythebehavioroftheNONErxgrouppipeline–Example:Usepsnone_tda.ra.txdel.tx_delaytomodifythevalueusedbytheNONEtxdelpipelinestageBeijingCreditTopCo.,.AllODBODBCommandobjprinthasanthatcausesODBtodis ycurrentpipelinestageresultsforradiotransmitterandreceiverchanneloutputtoODBconsoleBeijingCreditTopCo.,.AllODBODBCommandProvidesawaytofollowtransmissionsandreceptionsbysettingbreakpointsspecificLikemstopcommandonTx/Rxmodules,butspecifictoasingleSyntax:comstop<link_objref>|<tx_objref>:<rx_objref>[<ps–link_objref-Objidorhierarchicalnameof–tx_objref-Objidorhierarchicalnameofachannel,module,or–rx_objref-Objidorhierarchicalnameofachannel,module,or–ps_name-nameofpipelinestage(s),space-Point-to-pointlink:txdel,propdel,error,andeccstagesBuslink:txdel,closure,propdel,coll,anderrorstagesRadiolink:txdel,closure,chanmatch,tagain,propdel,ragain,power,inoise,bkgnoise,snr,ber,error,eccsupported–Wildcardssupported,i.e.–ODB>comstop*|*:*→stopatany–ODB>comstop1242:*→stopatcommunicationfromtransmitterofObjid–ODB>comstop*txdelpropdel→stopatcommunicationonanyobjectintxdelorpropdelpipelinestagesBeijingCreditTopCo.,.AllVisualizationVisualization&AnimationofTxDrawslinesconnectingtransmitterstoallreceiversintherxgroupwhenthetransmissionstarts&removesthemuponreceptionontheparticularreceiver’sendDrawspulsatingcirclesaroundthetransmittingnodewhentransmissionstarts&removesthemwhenthetransmissionendsDrawspacketflowsalongastraightlinebetweenthetransmitter&–Firsthalftraversedwhentransmission–SecondhalftraversedwhenreceptionUsesvaryingcolorsuniquetoasingleChangespacketicontovariationwithred-Xforfailedreception&packettitletonameoffailedpipelinestageBeijingCreditTopCo.,.AllWirelessWirelessModule“Built-In”Theradiotransmitterandradioreceiverobjectshavebuilt-in–BER,Busy,CollisionStatus,PacketLossRatio,ReceivedPower,Throughput,Utilization,–DependsontheTDAspopulatedbypipeline–Ifthepipelinestagesaremodified,thestatisticsregisteredmightnothaveaccurate