r&s cmu200 universal radio communication...
TRANSCRIPT
Version
03.00
July
2007
¸CMU200 Universal Radio Communication TesterTesting Applications in Mobile Radio Communications
Ethernet RF
HTTP
ser
ver
Vide
o st
ream
ing
MM
SC
FTP
serv
er
Services
TCP / UDP
IP
Data link layer
Physical layer
Applications
. . .
Ether- net
RF
Relay
Web
bro
wse
r
Vide
o st
ream
ing
MM
S cl
ient
TCP / UDP
IP / PPP / ...
PDCP / RLC / MAC
Physical layer
. . . . . .
IP
Data link layer
Physical layer
IP
PDCP / RLC / MAC
Physical layer
� ¸CMU 200 Applications
¸CMU200 goes Internet: testing data applications
The highly successful R&S®CMU200 uni-versal radio communication tester, which was originally designed as a pure RF tester for the various mobile radio standards used around the world, now enables addition-al user groups to test voice and video tele-phony as well as applications based on the Internet protocol (IP), such as web browser
or file transfer.
Becauseoftheincreasedtransmissionratesandenormouscomputingpowerofmodernmobilephones,developersandmanufacturersarefacedwithnewtestrequirementsduetothewealthofnewapplications.
Bymeansofawiderangeoftests,the¸CMU�00supportsapplicationsbasedoncircuit-switchedconnections,suchasshortmessageservice(SMS),traditionalvoicetransmission,ormodernvideotelephony.ThesameappliestoIP-data-basedapplicationsonthebasisofpacket-switchedconnections.
Appealing compact solution
Bothdevelopingandprovidingdataap-plicationsformobileradiopresentamul-titudeofnewchallenges.Mostapplica-tionsindatacommunicationsarebasedontheInternetprotocol(IP),whichinturnisbasedontheclient-serverprinci-ple.Thismeansthataclientusesamo-bilephonetorequestservicesthatareprovidedbyaserverinthecommunica-tionsnetwork.ThesoftwarefortheseapplicationsisusuallydevelopedonPCs;afteritsimplementationandextensivecomputersimulations,thesoftwareisportedtothemobilephone.Toperformfurthertestsonthemobilephoneitself,apublicmobileradionetworkorthesim-ulationofsuchanetworkisrequired.
Uptonow,radionetworkscouldusu-allybesimulatedonlywiththeaidofcomplexsetups.ThisisremediedbytheR&S®CMU�00,whichisaveryinterest-ingalternativeforsuchtasks.Duetotheextensivepossiblesettingsitoffers,testscanalsobeperformedonfrequencybands,forexample,thatarenotneces-sarilypartofanavailablepublicradionetwork.
Beforecommunicationsservicescanbelaunchedonthemarket,networkopera-torsmustsubjectthemtointeroperabilityteststoensurethattheyoperatesmooth-ly.Withthemultimediamessageservice(MMS),forexample,thecorrectexchangeofmessageswiththeserverimplemen-tationinthenetworkorbetweenmobilephonesfromdifferentmanufacturersischecked.Moreover,makingobjectivecomparisonsunderuser-definableandrandomlyreproducibleoperatingandtestconditionsisanotherpivotalfunctionthistargetgroupneeds.
Test setup
Applicationtestsetupsbasicallyconsistofamobilephone,theR&S®CMU�00,andaPC.Themobileradiotester,whichisconnectedtothemobilephoneviatheradiointerface,simulatesthemo-bileradionetwork.ViaanEthernetcon-nection,itaccessestheIP-basedcom-puterworld,whichcanbeeitheralo-calareanetwork(LAN),theInternetor,atitssimplest,acontroller,wheretheserversprovidingthecommunica-tionsservicescanbeaccessed.Theus-erusuallyaccessestheseservicesfromthemobilephoneviamobileoriginatedcalls.TheR&S®CMU�00bridgesthegapbetweenwireddatacommunicationsandradiocommunicationsacrossvariousprotocollayers.
¸CMU 200 Applications �
Versatile test scenarios
Go/NoGotestsstartanapplicationonthemobilephoneandtesttheoperationfromtheuser‘sviewpoint.ThesetestsdifferfromRFmeasurementsperformedwiththeR&S®CMU�00bycoveringtheentireoperatingsystemofaphoneandsubjectingittotheappropriatestress.Afteranapplicationpassesthisbasictest,performancemeasurementsareusuallycarriedout;theiraimistoana-lyzetheachievabledatatransmissionratesinthedownlinkandtheuplink.
Networkoperatorsoftenrequireproofthatminimumdataratesareachievedunderspecificconditions.The¸CMU�00allowssuchconfirmation.
Anothernoteworthycriterionthathelpsdeterminethepracticalvalueofmo-bilephonesistheiroperatingtimewithrechargeablebatteries.Tominimizeaphone’spowerconsumption,youneedtomeasuretheconsumptionwhileanappli-cationisactivesothatyoucanfindoutmoreaboutpossibleoptimizationproce-dures.Ifrequired,themobileradiotestersimultaneouslyrecordsdetailedinforma-tionabouttheprocessedprotocollayersinalogfile,whichisthenavailableforfutureevaluationandanalysis.
Interactiontestsanalyzehowdifferent,simultaneouslyactiveapplicationsonamobilephoneaffecteachother.Thesetestsanalyze,forexample,whatwillhappenifanSMSarriveswhileavideoisbeingdownloadedandthecalendarfunctionisoutputtinganalarm.
Interoperabilitytestscheckwhethermo-bilephonesfunctionsmoothlywithinanetwork,forexamplewheninteractingwiththenetworkoperator’sMMSserv-er,orwhentwophonesfromdifferentmanufacturersinteractwitheachoth-er.Inthesimplestcase,justonephoneisusedintheechomodetoperformacombinedtransmission/receptiontest.
Forthistest,anMMSisgeneratedonthemobilephoneandthensentbacktothesamephoneiftheoriginatingphonenumberisenteredattransmittal.Beforeanewmobilephonereachesthemarket,itmustundergoanumberofteststoen-surethatiscustomer-ready.IntheEMCtest,forexample,thetelephonemustoperatereliablyinthelabduringsimul-taneoustransmissionandreceptionofdataandremainlargelyunaffectedbystrongelectromagneticfields.
Whenthe¸CMU�00iscombinedwiththe¸ABFSfadingsimulator,theoperationofamobiletelephoneun-dervariousfadingscenariossuchasinanautomobileatvariousspeedsandre-ceptionconditionscanbesimulated.Thus,thereliabilityofdataexchangecanbetestedandevaluated.
Incontrasttoapracticaltestinapublicmobileradionetwork,the¸CMU�00makesitpossibletoindividuallydefineallradioparametersas,forexample,fieldstrengthorchannelcoding,andtorepeatthemasoftenasdesiredatanytime.Theperformanceofdifferentmo-bilephonesorimplementationscanthusbeobjectivelyevaluatedandcomparedinbenchmarktests.
TCP/IP services
Theclientsonthemobilephonerequiresuitableserversatthecontrollerendasacounterpartforapplicationtests.TheR&S®CMU�00applicationtestingop-tionsallowIP-baseddataapplicationstobetestedonamobilephone;inad-dition,theyincludeseveralTCP/IPserv-ers,forexampleanHTTPserver,whichallowsyoutostartawebbrowseronamobilephone.
Rohde&Schwarzoffersadditionalprod-uctsfordevelopingandcertifyinganum-berofmobile-phone-specificapplica-tionssuchasMMSorpush-to-talkovercellular(PoC).TheMMScenter(MMSC),astandard-conformingserver,allowsthebasefunctions,i.e.transmittingandre-ceivingmultimediamessagesonmobilephones,tobetested.The¸CA-AA0�and/or¸CA-AC0�optionsfromRohde&SchwarzverifyifaPoC-capablemobilephoneperformsinaccordancewiththestandard.
Future prospects
Applicationtestsarebecomingmoreandmoreimportantinmobileradio.Rohde&Schwarzismeetingthistrendbycontinuouslydevelopingnewsolu-tionsinthisfield.Thelicensingauthor-itieshaverespondedtochangesinthewaymobilecommunicationsareused:Bydevelopingtestscenarioswithexactspecifications,theydefineappropriatetestsattheapplicationlevelthatwillen-surethatmobileradionetworkswillalsooperatesmoothlyinthefuture.
� ¸CMU 200 Applications
Versatile application tests in (E)GPRS mobile radio
The ¸CMU-K92 software option allows you to test applications for 2.5G mobile phones. For example, you can now test the transmission or reception of multimedia message services (MMS), Internet brows-ing, or video streaming within a simulated (E)GPRS network environment. In addition to measuring the known RF parameters of power, spectrum or modulation, you can now also perform such tasks as displaying
data throughput or analyzing protocols.
Recording of all exchanged IP data packets with time stamp and display of the data transmission rate achieved.
Throughput of IP data exchanged between mobile phone and radio network in uplink (UL) and downlink (DL).
(E)GPRS application tests with the ¸ CMU200
Owingtosignificantprotocolstackex-tensions,the¸CMU�00alsoallowsyoutotestapplicationsviaGPRSandEGPRS(EDGE)mobilephonessimplybyactivatinganewsoftwareoption.The¸CMU-K9�softwareoptionmakesitpossibletotestalmostanyIP-basedap-plicationsinpacket-orientedmodeviaanIPgateway.Youcansimplytestproperfunction-ing,butalsocheckwhetherdifferentapplicationsthataresimultaneouslyac-tivatedonamobilephonerunsmoothly.
GPRSandEGPRS,theoffshootsoftheGSMstandard,achievedatatrans-missionratesofupto171.�kbit/sand�7�.6kbit/srespectively,thusallowingamultitudeofapplicationstobecarriedout,someofthemevenwithrealtimere-quirements.InadditiontodisplayingthecurrentdatathroughputoftheIPpack-etsexchangedbetweenmobilephoneandserver,theR&S®CMU�00alsore-cordsvarioustransmissionprotocols.Designengineersarethusabletothor-oughlyanalyzenotonlytheIPprotocol,butalsoanumberofotherradio-spe-cificprotocolssuchasradiolinkcontrol(RLC)ormediumaccesscontrol(MAC).Regardlessoftheseactivities,itisstillpossibletomeasureandanalyzetheRFsignalstransmittedbyGPRSorEGPRSmobilephonesontheR&S®CMU�00withrespecttopower,spectrum,ormodulation.Unliketheprevioustrans-mittertest,themeasurementisnowper-formedaspartoftheapplicationdatatransmissionandnolongerontheba-sisofpseudo-randombinarysequenc-es(PRBS).IftwoR&S®CMU�00testersareavailable,theapplicationtestscanbeexpandedtoaccommodatedataend-
to-endtests,forexampleforcheckingtheexchangeofanMMSmessagebe-tweentwomobilephones.IfonlyoneR&S®CMU�00isavailable,thetransmis-sionandslightlydelayedreceptionofanMMSmessagewithonemobilephonecanalsobeimplementedusingtheloop-backsettingintheMMSC.
Automation
Toreducestaffcosts,repetitivetestrou-tinessuchasbenchmarktestscanbeautomated.Byusingacontrolprogram,allsettingsrequiredforautomationcanbeautomaticallymadeviastandardizedinterfaces.Measurementresults,e.g.datathroughput,arerecorded.
¸CMU 200 Applications �
Powerful aid in the development lab
TheR&S®CMU-K9�softwareoptionfortheR&S®CMU�00allowsapplicationde-signengineerstotesttheirworkinthelabonmobilephonesinasimulatedra-dionetwork.Inthiscase,themainfo-cusisonprovingthattheapplicationrunssmoothlyonthemobilephoneundernor-maloperatingandradioconditions.Fortheseapplications,whichcanbedivid-edintomobile-originatedandmobile-ter-minatedapplications,thisrepresentsthefirstrealistictestaftercompletionofthesimulationtestsonthedevelopmentcom-puter.Whentestingmobile-originatedapplications,datacommunicationisini-tiatedonthemobilephone,forexam-plebycallingupanintegratedbrowserwithsubsequentaccesstothedataofawebserverconnectedviatheEthernetin-terfaceoftheR&S®CMU�00.Anexam-pleofatestofamobile-terminatedap-plicationisanSMStransmission,eitherfromacomputerconnectedtothetesterordirectlyfromthetestertothemobilephone.
Future prospects
The¸CMU-K9�optionistheplat-formforfurtherapplicationtests.ItisrequiredinordertorunvalidatedMMStestcasesortotestcomplexapplicationssuchaspush-to-talkovercellular(PoC).Intheforthcomingconfigurations,dataapplicationscanalsobetest-edwhilevoicetransmissionisinprog-ress.Iffeasiblewiththemobilephone,bothapplications(circuit-switched/packet-switched)canthenbeoperatedandtestedsimultaneouslyinthedualtransfermode.
A test setup for an end-to-end test between two mobile phones for testing for problem-free MMS exchange between mobile phones from different manufacturers, for example.
The ¸CMU 200 can also measure spectra, power, and modulations. Here is an example of a power measurement during a file transfer with four slots in the uplink and triggering in response to combined GMSK/8PSK modulation.
6 ¸CMU 200 Applications
WCDMA/HSDPA/HSUPA: data applications and video telephony test
The ¸CMU-K96 option makes it possi-ble to test data applications on WCDMA/
HSDPA/HSUPA mobile phones.
In the ACK/NACK menu, the tester displays the data throughput, the CQI median value and the percentages of the ACK, NACK, and DTX val-ues: ACK (DUT has acknowledged), NACK (DUT has not acknowledged and may request a re-peat transmission), DTX = discontinuous trans-missions (DUT was expected to respond but did not).
Settings and measurement results
TheconfigurationoftheRFparametersofaWCDMAradionetworkcanbedy-namicallyadjustedontheR&S®CMU�00duringapplicationtesting.Changingthechannelnumberstriggersanintracellhandover,forexample,whichisrequiredifco-channelinterferenceconsiderablyimpairsthesignalqualityinradionet-works.Sinceareducedtransmitlevelin-creasesthebiterrorprobabilityatthere-ceiverend,anapplicationfunctiononamobilephonecanalsobetestedunderadversereceiveconditions.Iftheappli-cationtestisperformedincompressedmode,themobilephoneissubjectedtoadditionalstress,whichallowsyoutocheckthequalityoftheUEreporttrans-mittedfromthemobilephonetothetes-ter.Whileanapplicationisrunningonthemobilephone,theknowntransmit-
termeasurementssuchaspower,codedomainpower,spectrum,andmodula-tioncanstillbeperformed.Theblockerrorratio(BLER)determinedbytheR&S®CMU�00isusedtoevaluatethereceiverinthemobilephone.
Forsimpletests,the¸CMU�00in-ternallyprovidesservicesforPINGandfiletransferprotocol(FTP)datatransfer.Usingthissimpletestconfiguration,datatransmissionsoffilescanbetestedeveninthemegabitrange.
HSDPA/HSUPA
ThedatatransmissionratesintestsofWCDMAmobilephonesextendintothemegabitrangeinthedownlink(highspeeddownlinkpacketaccess,HSDPA)anduplink(highspeeduplinkpacketaccess,HSUPA).Asalways,allrelevantRFparameterscanbemeasuredandap-plicationscanalsobetestedinthesetwocases.Ofparticularinterestaredatathroughputmeasurements,whichareperformedwithregardtothephysical
layerortheradiolinkcontrol(RLC)pro-tocol.WiththeRLCprotocol,thedatathroughputversustime,aswellassta-tisticsconcerningthetransmittedpro-tocoldataunits(PDU)andservicedataunits(SDU)aredisplayed.Thisprovidestheuserwithaninformativeevaluationofdatatransmissioninthedownlinkanduplinkataglance.
Remote control and automation
Toremote-controltheR&S®CMU�00duringapplicationtests,anIEC/IEEEbusinterfaceisavailable;itcanbeused,forexample,toautomaticallyobtainmea-surementresultsandmeasurementvalues–aprerequisiteforprogram-con-trolledsequences.Suchautomaticallyrunningtestscanberepeatedatanytimeandasoftenasnecessarywith-outstaffintervention,thushelpingtoincreasethesystem’sefficiency.
Protocol analysis
Afterthesoftwarehasbeenportedtothemobilephone,usersoftenwanttorecordprotocolstooptimizeinternalprocessesortoperformanerroranalysisthatmaybenecessary.TheR&S®CMU-Z�6WCDMAmessageanalyzerandrecorderoptionallowsalluniversalterrestrialradioaccessnetwork(UTRAN)protocollayerstoberecorded,whichcanthenbeusedformoredetailedanalysis.Thispowerfultoolpermitsin-depthanalyses,includingtransportlayeranalyses.
¸CMU 200 Applications 7
The ¸CMU-Z46 WCDMA message analyzer and recorder option records all UTRAN protocol layers affected by communications between the ¸CMU200 and the mobile phone. The top half of the screen shows a list of all recorded protocol layers. The individual layers can be selected and their contents analyzed in detail (bottom half of screen).
Video telephony
Inalllikelihood,videotelephonyisthemostspectacularnewWCDMAapplication.Itisuniqueinthatitiscir-cuit-switched,andnotIP-basedlikethepreviouslydescribedapplications.TheWCDMAfirmwarechecksthisfunctionalitywithoutrequiringoptionalextensions.Thetestisperformedinechomode,wherethetransmissionandre-ceptionofvideoandaudiosignalscanbecheckedwithjustonemobilephone.ThevideotelephonysignalstransmittedbythephonetotheR&S®CMU�00areloopedbackbytheradiotesteranddis-playedbythephoneaswould-bevideoandaudiosignalsofacalledstation.
Future prospects
Theapplicationtestissuretogainin-creasingimportanceoverthenextfewyears.Rohde&SchwarzwillcontinuetoenhancethefunctionalscopeoftheR&S®CMU�00’scurrenttestfunctionstomatchmarketrequirements.
Example of Receiver Quality/RLC BLER measurement during an HSDPA/HSUPA data end-to-end connection.
Imagesenttothe¸CMU�00
Imageloopedbacktothemobile
Video telephony test in a loop-back
� ¸CMU 200 Applications
Testing CDMA2000® data applications
With the ¸CMU-B87 option (interface for data testing) and ¸CMU-K87 option (application testing), the ¸CMU200 of-fers comprehensive test capabilities for CDMA2000® 1xRTT and 1xEV-DO packet
data application testing.
Statistical evaluation of data transfer between the ¸CMU 200 and the mobile phone during the application test. After the RLP (radio link protocol type 3) and IP data packets are exchanged, the transmitted and received packets are evaluated using different criteria.
CDMA�000®isaregisteredtrademarkoftheTelecommu-nicationsIndustryAssociation(TIA-USA).
Extensive test capabilities
TheCDMA�000®1xRTTmobileradiostandard,whichwasdevelopedbythe�GPP�standardizationbody,isofficiallyrecognizedbytheITUasanIMT-�000standardforthethirdmobileradiogeneration(�G).Revision0(orA),allowsdataratesofupto�07.�kbit/sina1.��MHzfrequencychannel.The�GPP�1xEV-DOstandard,whichwasdevelopedforpuredataapplications,willbeusedtoanincreasingextentinthefuture.Thelatestversionofthisstandard(1xEV-DORel.A)allowsamaximumdatarateof�.1Mbit/sintheforwardlink(basesta-tiontomobilestation)and1.�Mbit/sinthereverselink(mobilestationtobasestation).
Inthesenetworks,datalinksbasedontheInternetprotocolareplayingamoreandmoresignificantrole.ThiscallsfornewtestproceduresdesignedtoverifythefunctionalityofIP-basedlinks.TheTIA/EIAstandard,forexample,specifiesdifferenttestscenariosforpacket-orient-eddatalinks.
Service Option 33InitsServiceOption��,theTIA/EIAstandardIS-707-A-1specifiesIP-baseddatalinksfortheCDMA�000®standard.TheR&S®CMU�00providesallparam-etersrequiredforthisserviceoption,rangingfromtrafficchannelconfigura-tion(dataratesofupto1��.6kbit/scanbesetforthesupplementalchannel(SCH)bothfortheforwardandthere-verselink)throughtotheparametersformobileIPandauthentication.
PPP authenticationForsettingupapoint-to-pointprotocol(PPP)link,theR&S®CMU�00canbecon-figuredtorequestPPPauthenticationfromthemobilephone.
TheR&S®CMU�00supportstwometh-odsofauthentication:CHAP(challengehandshakeauthenticationprotocol)andPAP(passwordauthenticationprotocol).Onreceivingtheauthenticationrequest,themobilephonereturnstheusernameandthepasswordenteredforthelinksetup.Thetestercheckswhethertheusernameandpasswordarevalid.FortheCHAPprotocol,periodicallyrepeat-ingauthenticationcanbeconfigured.FormobileIPlinks,themobileIPstan-dardstipulatesthatauthenticationbedeactivated.
Mobile IPMobileIPisanadditiontothecon-ventionalInternetprotocol.Itmakesthemovementsofamobilecomputer(mobilenode,i.e.inthiscaseamobilephone)transparentfordataapplicationsandthehigherprotocollayers.
AmobileIPenvironmentinvolvestwonewnetworkelements–thehomeagentandtheforeignagent.Thehomeagentislocatedinthemobilephone‘shomenetwork;itknowsthemobilephone‘scurrentlocationand“tunnels”datapacketsdirectedtothemo-bilephone‘shomeaddresstothemo-bilephone‘scurrentlocation.Thefor-eignagentassignsthemobilephoneatemporaryaddressintheforeignnet-work(foreignagentcare-ofaddress)andfunctionsastheterminalpointofthetunneldepartingfromthehomeagent.
Cableconnections
Homenetwork
Web server,mail server, etc
R&S®CMU200(base station)
Mobile node(mobile station)
Foreignnetwork
Foreign agent
Home agent
Virtualaccess point
of mobile node
Data from/to mobile station
InternetIP tunnel
¸CMU 200 Applications 9
Typical test setup for mobile IP link with mobile station and reference to home agent and foreign agent.
Byusingthe¸CMU�00,internalsin-gle-boxsolutionscanbeimplemented,ascanmobileIPtestscenarios,whichrequireaseparatehomeandforeignagent.
PPP link statusDuringperiodsinwhichthemobilephoneisnottransmittingorreceiv-ingdata,itswitchestoanidlestatereferredtoasdormantmode.Inthismode,thePPPlinkismaintained,butnotrafficchannelconnectionsaresetupintheCDMA�000®network.TheR&S®CMU�00indicatesthevariousPPPstatesthemobilephonecanassume:
Registered mobilephoneisregistered,noPPPlinkisestablished
PPP Connected PPPlinkisestab-lished,trafficchannelconnectionsaresetup,mobilephonetransmits/receivesdata
PPP Dormant PPPlinkisestablished,notrafficchannelconnectionsaresetup,mobilephonedoesnottransmit/receivedata
TX/RX RLP frame and IP packet statisticsAstatisticalevaluationbasedoncountsofthedifferentparametersmakesitpos-sibletotrackthedataflowthroughthebasestation,i.e.theR&S®CMU�00.Thefollowingtypesofdataarecountedsep-aratelyfortheTXandRXdirections:
RLPframesThedifferentRLPframetypes(IDLE,FILL,ACK,etc)TotalPPPbytesTotalPPPpacketsTotalTX/RXdatarate
Application scenarios
TheR&S®CMU�00allowsdifferenttestsetupstobeimplementedfordifferentapplicationscenarios.Inthesimplestcase,youcanoperatethetesterinthestandalonemodetoperformdataratemeasurementsonthemobilephoneundertest.
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10 ¸CMU 200 Applications
Application enabler and validated test cases with the ¸CMU 200 and ¸CRTU
Rohde & Schwarz has expanded its portfolio by test solutions for developing, verifying, and certifying mobile-telephone-specific applications such as MMS (multimedia messaging service), PoC (push-to-talk over
cellular), or DM (device management).
Themodernmobileradiostandardsarethebasisforpowerfulcommunicationsanddatatransmissionnetworksofferingattractiveapplicationssuchasthetrans-missionofpictures,videoclips,ormu-sicfilestooneormoresubscriberssi-multaneously.Forthispurpose,amobilephoneusesthemultimediamessagingservice(MMS),whichtransmitsacombi-nationoftextandmultimediafiles.
PoC,themodernversionofwalkie-talkiecommunication,isaverypromisingnewvoicecommunicationsserviceinmobileradionetworks.Voicemessagesaredi-rectlysenttooneormorepredefinedsubscribersatakeystroke.
Furthermore,mostcommunicationspro-gramsastheyareknowninconnectionwiththeInternetareavailabletomobileusers.OnthebasisoftheInternetpro-tocol(IP),theseprogramscanbetest-edwiththeaidoftheR&SCMU�00ap-plicationtestingsolution.Inthecaseofwebbrowsing,theuserinterfacein-cludesanintegratedhttpserverforsim-plefunctionaltests.
MMS – a new challenge in mobile radio networks
Networkoperatorsmustensuresmoothmultimediafileexchange.However,asaprerequisiteforanefficientnetwork,allmobilephoneshavetomeetspecificmin-imumrequirementsforhandlingthefileformatsused.Forexample,becausedis-playsizesdiffer,allmobilephonesmust
beabletodisplayandreplaythepicturesandvideoclipstransmittedinvarioussiz-esandfileformatsinsuitablequalitywith-outnetworkoperatorshavingtoprovideconversionaidsforthedifferenttypesofmobilephonesinthenetwork.Otherwise,forexample,apicturesentinGIFformattoamobilephonethatcanonlyprocessJPEGformatwouldhavetobeconvertedinthenetwork.Inviewofthemultitudeofdisparatemobilephonesandfilefor-mats,thistaskwouldbevirtuallyimpossi-bletohandle.
TheMMScenteristhecoreofthenewsolutionfromRohde&Schwarz.Itallowsmultimediamessagestobesentandre-ceived.TheMMSCwasspeciallyde-signedforMMStesting.Astheinter-nalMMSCstatescanbeviewed,itof-fersmaximumtransparencyfortrouble-shooting.
AparserandaviewerformthecoreoftheMMSC.Theparsersplitsthemulti-mediamessageintoitsindividualcon-tents;comparingthesecontentswiththereferencecontentsverifiesifamo-bilephoneoperatescorrectly.Thesup-pliedviewercandisplaypicturesorvid-eosandisusefulinfindingoutwhyadisplayisnotcorrect.
PoC – go ahead
PoCisbasedontheIPmultimediasub-system(IMS)standardizedby�GPP.Thisisamultimediaswitchingtechniquede-scribingdifferentIP-basedmultimediaapplications.IMSformsthebasisforthepacket-switchedtransmissionofmulti-mediadata;itmanagesthesetup,con-trol,andreleaseofconnections.Specialrealtimeprotocols(RTP,RTCP,TBCP)ad-ditionallyensureoptimumvoicetrans-missionviathedatanetwork.
Thevoicemessageisconvertedtoada-tastream,packedindatapackets,andsenttothePoCserverofthenetworkoperatorviaradio.ThedatapacketsfindtheirwaythroughthedatanetworkbymeansoftheInternetprotocol(IP).Thevoicecommunicationsserviceisbasedonaclient-serverarchitecture.ThePoCclientonthemobilephoneusestheser-vicesofthePoCserverinthenetwork.ThePoCservertransmitstheincom-ingdatastreamtooneormorereceiv-ersandthedatastreamisreceivedtherewithonlyafewsecondsdelay.Onemes-sagethusreachesmanyreceiversatatime.Tocontrolcorrectcommunications,thePoCserveradditionallytakesoversignalingandensuresthatonlyonesub-scribercantransmitdataandusethevoicechannel.Italsocontrolsthespeci-fiedcommunicationsgroups.
Minimum standard with new test cases
Tocircumventsuchproblems,amin-imumstandardfortransmittingmulti-mediafileshasbeendefined.Onbe-halfoftheGlobalCertificationForum(GCF),theOpenMobileAlliance(OMA)specifiedtestcasesbymeansofwhichitispossibletoverifywhethermobilephonescomplywiththisminimumstan-dardwhenreproducingmultimediacon-tent.Someofthesetestcasesweread-optedbytheGCFandthePCSTypeCertificationReviewBoard(PTCRB)andhavethusbecomepartofthecertifica-tionforallmobilephonessupportingMMS.Unlikesignalingtestcases,thesetestcasesverifyapplicationlayersin-steadoflowerprotocollayers.
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¸CMU 200 Applications 11
MMS test cases
Forreceptiontests,OMAprovidesref-erencesthatalsoincludepicture,video,andsoundfilesindifferentformatsandsizes.Fortestpurposes,amultimediamessageissenttothemobilephone;visualoracousticcomparisondetermineswhetherthedisplayon,orreplayby,themobilephonecomplieswiththerefer-encecontent.Tofacilitatecomparingtheresultsonthemobilephonewiththeref-erencecontent,thereferencecontentisdisplayedonthescreenafterthemes-sagehasbeensent.
Unlikereceptiontests,transmissiontestscanbeevaluatedautomatically.Forthispurpose,themobilephonesendsames-sagewithmultimediacontenttothepro-tocoltester.Usingaparser,theprotocoltestersplitsthecontentintoseparatemediafilesandtheSMILspecification,checkswhethertheycomplywiththereference,andthenindicateswhetherthemobilephonehaspassedthetest.Amanualfilecomparisonusingaviewer,i.e.asuppliedprogramthatcandisplaypicturesandvideosandreplaymusicfiles,isofcoursealsopossible.
PoC test cases
PoClargelyreliesontried-and-testedIP-basedprotocols,suchasthesessioninitiationprotocol(SIP),realtimetrans-portprotocol(RTP),RTPcontrolprotocol(RTCP),andsessiondescriptionprotocol(SDP).TheseprotocolswereexpandedbyPoC-specificparameters.
PoCexpansionsandtheinteractionoftheprotocolsusedcanbecheckedwiththetestcasesclassifiedbytheGlobalCertificationForum(GCF).
DM test cases
Devicemanagement(DM)isastandardapplicationformanagingsoftwareonamobilephone.Viaaweb-basedapplica-tion,youcanchangeorupdatethemo-bilephone'ssoftware,handledebug-gingissues,orinstallapplications"overtheair".Inthatway,thecontentonalostorstolendevicecanalsobeeasilyremoved,andsensitivedocumentsdonotarriveinthehandsofothers.
Validatedtestcaseshelptoensureandtestthestandard-compliantimplemen-tationofthisfeatureonmobilephones.Thetestcasesareimplementedintheopen,standardizedtestlanguageTTCN-�,whichallowstheteststobeeasilysimulatedandalsomodifiedtosuittheuser'srequirements.
Fit for the future with solutions from Rohde & Schwarz
BothserversandthePoCtestcaseshavebeenimplementedassoftwareproductsrunningonPCsbasedonWindows.ThelinkbetweenthemobilephoneandthePCiseitherthe¸CMU�00Universalradiocommunicationtesterorthecorre-spondingdevicesoftheR&S®CRTUpro-tocoltesterfamily.Thesedevicessim-ulateamobileradionetworkandmakeitpossibletocallupanyIP-basedappli-cationsofamobilephonesuchasPoC.Incontrasttopublicmobileradionet-works,youcanindividuallydefinethera-dioparametersduringsuchtestsandre-peatthetestanytimeunderreproduc-ibleconditions.Thesuppliedtestcasesonlyincludetestsattheapplicationlevelandareindependentofthemobileradiostandard.
Future prospects
WiththeR&S®CRTU-ATEapplicationtestenvironmentsoftwareplatform,theRohde&Schwarztestsolutionportfolioindigitalmobileradiorangesfromthephysicallayeruptotheapplicationlay-er.Besidesthedevelopmentandavail-abilityofnewmultimediaapplications,additionaltestsolutionswillfollowonthisbasis.
Certified Quality System
ISO 9001DQS REG. NO 1954 QM
Certified Environmental System
ISO 14001DQS REG. NO 1954 UM
Moreinformationatwww.rohde-schwarz.com(searchterm:CMU�00)
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www.rohde-schwarz.comEurope:+�91�0�1�����,[email protected]
USAandCanada:+1-���-��7-�77�,[email protected]:+6�6�1�0���,[email protected]