Diese Präsentation wurde erfolgreich gemeldet.
Wir verwenden Ihre LinkedIn Profilangaben und Informationen zu Ihren Aktivitäten, um Anzeigen zu personalisieren und Ihnen relevantere Inhalte anzuzeigen. Sie können Ihre Anzeigeneinstellungen jederzeit ändern.

Ericsson Technology Review: Meeting 5G latency requirements with inactive state

170 Aufrufe

Veröffentlicht am

Low latency communication and minimal battery consumption are key requirements of many 5G and IoT use cases, including smart transport and critical control of remote devices. Thanks to Ericsson’s 4G/5G research activities and lessons learned from legacy networks, we have identified solutions that address both of these requirements by reducing the amount of signaling required during state transitions, and shared our discoveries with the 3GPP.

This Ericsson Technology Review article explains the why and how behind the new Radio Resource Control (RRC) state model in the standalone version of the 5G New Radio standard, which features a new, Ericsson-developed state called inactive. On top of overcoming latency and battery consumption challenges, the new state also increases overall system capacity by decreasing the processing effort in the network.

Veröffentlicht in: Technologie
  • Als Erste(r) kommentieren

  • Gehören Sie zu den Ersten, denen das gefällt!

Ericsson Technology Review: Meeting 5G latency requirements with inactive state

  1. 1. LTE/NR RAN Legacy idle-to-connected transition New inactive-to-connected transition NR RANCN CNUEUE RRC connnection request Initial radio synchronization RRC resume request RRC resume RRC resume complete UL/DL user data RRC connection setup RRC connection complete (service request) RRC security setup RRC security complete UL/DL user data RRC reconfiguration (bearer setup) RRC reconfiguration complete Initial UE message (service request) UE context setup (keys, bearers) Initial radio synchronization UE context setup complete Initial radio synchronization ERICSSON TECHNOLOGY THEINACTIVESTATE IN5GNEWRADIO C H A R T I N G T H E F U T U R E O F I N N O V A T I O N | # 0 6 ∙ 2 0 1 9
  2. 2. ✱ INACTIVE STATE IN 5G NR 2 ERICSSON TECHNOLOGY REVIEW ✱ JUNE 19, 2019 Reducing the amount of signaling that occurs during state transitions makes it possible to significantly lower both latency and battery consumption – critical requirements for many Internet of Things and 5G use cases, including enhanced mobile broadband. ICARO LEONARDO DA SILVA, GUNNAR MILDH, PAUL SCHLIWA-BERTLING, MAGNUS STATTIN, ALEXANDER VESELY Many of the performance improvements in 5G New Radio (NR) that are designed to support new Internet of Things (IoT) use cases such as critical control of remote devices and smart transport [1] are based on lessons learned from research and development on 4G LTE networks. One example of this relates to the transition of wireless devices from a power- saving state where data is not exchanged (idle state) to a connected state optimized for data transmissions (connected state). ■ Studiesshowthatawirelessdevice’stransition fromapower-saving(idle)statetoaconnectedstateis themostfrequenthigh-layersignalingeventin existing4GLTEnetworks,occurringabout 500-1,000timesaday.Thetransitioncomprisesan extensivesignalingsequencebetweenthedeviceand thenetwork,andbetweennetworknodes,whichcan leadtoconsumerlatencyissuesandhighbattery consumption. Thecombinationof4G/5Gresearchactivitiesand lessonslearnedfromlegacynetworkshasmadeit possibletodevelopsolutionsthatreducetheamount ofsignalingrequiredatthesetransitions,thereby loweringbothlatencyandbatteryconsumption significantly.Thedecreasedsignalinginthenetwork alsoresultsinanincreaseinoverallsystemcapacity. Ericsson’scontributionstothe3GPP standardizationofsolutionsinthisareainclude a newRadioResourceControl(RRC)statemodel adoptedinthestandaloneversionofthe5GNR WITH INACTIVE STATE Meeting 5Glatency requirements
  3. 3. INACTIVE STATE IN 5G NR ✱ JUNE 19, 2019 ✱ ERICSSON TECHNOLOGY REVIEW 3 standard.Improvedconnection,stateandmobility handlingarekeyelementsofefficientsupportfor currentandfuture5Gusecaseswithalargeand growingnumberofdevices. Conceptdevelopmentoftheinactivestate Allowingwirelessdevicestoenteralow-powerstate whentheyarenottransmittingorreceivingdatahas alwaysbeenanimportantpartofachievingabalance betweengoodcommunicationperformanceand acceptablebatteryconsumption.Formanyyears,two states–connectedandidle–weresufficienttomeet mostneeds. Thedevelopmentoftheinactivestatehaslargely beendrivenbythegrowingfieldofMachine-type Communication(MTC).InmostMTCscenarios, theamountofdatathatwirelessdevicestypically exchangewiththenetworkissmallandusuallynot urgentenoughtojustifythehighbatteryconsumption requiredtohandleallthesignalinginvolvedinthe legacyidle-to-connectedtransition.Toaddressthis issue,Ericssonplayedaleadingroleindeveloping thetransitionenhancementsthatwereintroducedin 4GLTERel-13,inwhichtwonewprocedureswere standardized:suspendandresume. Inthesuspendprocedure,theuserequipment (UE)–the3GPPnameforwirelessdevices–stores itsradioconfigurationandsecurityparameters whenittransitionsfromconnectedtoidle. Then,whenitneedstoconnecttothenetworkagain (duetosomeuplink(UL)databeingavailableto transmit,forexample)theUEtriggerstheresume procedure.Thisinvolvesrestoringthepreviously storedconfigurationandresumingtheconnection withouttheneedforextensivesignalingwiththe corenetwork(CN)orhavingtoreestablishsecurity, forexample.Theresumeprocedureissimilartothe sleepstateofacomputer,whichenablesworktobe pausedandresumedlaterwithoutrepeatingtedious start-upprocedures. Inparallelwiththe4GLTEworkthatwas completedin2015,Ericssonwasalsoworkingonthe 5Gconcept,whichincludedchallenginglatency requirementsandprovidingsupportforavarietyof newandemergingusecases.Withouttheconstraint tocomplywithanexistingstatemodel,itwas possibletofurtheroptimizethesuspend/resume solutionin5GNRbyintroducinganewstateknown asinactive.Thekeybenefitsoftheinactivestateare thatitsignificantlyreduceslatencyandminimizes thebatteryconsumptionofbothsmartphonesand MTCdevices. Inthelatterhalfof2015,webegantopromotethe inactivestateexternallyinthecontextofthe Ericsson-led5G-PPPEuropeanprojectMETIS-II, themain5Gpre-standardsproject[2].Themaingoal oftheprojectwastofacilitateresearchdiscussions withindustryplayers(UEvendors,network vendors,networkoperators,academicpartnersand soon)abouttechnicalcomponentstobringtothe 3GPPduringthe5Gstandardizationwork. Key terms Connected state – The UE is actively involved in sending or receiving data or signaling. Mobility is controlled by the RAN. Idle state – The UE is in a power-saving state and is known at tracking-area level in the CN. Inactive state – The UE is in a power-saving state and is known on RNA level in the RAN. Transition to the connected state is optimized.
  4. 4. ✱ INACTIVE STATE IN 5G NR 4 ERICSSON TECHNOLOGY REVIEW ✱ JUNE 19, 2019 Figure1showstheallocationof basicsystem functionsindiverseUEstates,highlightingthe evolutionfromRel-13suspendto5Ginactive. 5GNRinactivestateprocedures In2016,itwasagreedthattheinactivestatewouldbe introducedin5GNR[3],andthespecificationswere finalizedandapprovedinDecember2018[4,5].The mostnotableenhancementsarethesuspendand resumeprocedures,aswellasRAN-basedlocation managementandRANpagingforUEsintheinactive state.Inthesuspendprocedure,boththeUEandthe RANstoreinformationabouttheUEtransitionfrom connectedtoinactive,alongwiththeUEradio protocolconfiguration.Theresumeprocedure optimizesthetransitionfrominactivetoconnectedby restoringtheUEradioprotocolconfiguration.RAN- basedlocationmanagementandRANpagingmakeit possibleforUEsintheinactivestatetomovearound inanareawithoutnotifyingthenetwork. Suspend ThemainprincipleoftheinactivestateisthattheUE isabletoreturntotheconnectedstateasquicklyand efficientlyaspossible.WhentheUEtransitionsto inactive,boththeUEandtheRANstoreallthe informationnecessarytoquicklyresumethe connection.ThemessagethattransitionstheUEto inactivestatecontainsasetofparametersusedfor inactivestateoperation,suchasaRANNotification Area(RNA)withinwhichtheUEisallowedtomove withoutnotifyingthenetwork.Further,itincludes parametersusedforsecuretransitionbacktothe connectedstate,suchasaUEidentifierandsecurity informationneededtosupportencryptedresume messages. Resume AninactiveUEmayinitiatearesumeprocedure whenthereisaneedtotransmitdataorsignaling,for example.Inthiscase,theUEtransmitsanRRC resumerequestthatincludestheUEidentifier (providedbytheservingnodetoidentifytheUE’s configurationrepository)andasecuritytokentoverify thelegitimacyoftheresumerequest. Studiesof4Gnetworksshowthat,inmostcases, UEsthatleavethepower-savingstatereturntothe sameRANnodetheywerepreviouslyservedby.If, however,theUEresumesinacellservedbya differentRANnode,thattargetnodewillretrieve theUEconfigurationfromtheservingnodebased ontheUEidentifier. Figure 1 Comparison of the allocation of system functions UE RAN states IdleSystem functions Connected Rel-13 suspend 5G inactive CNMobility management RAN CN RAN CNPaging trigger n/a CN RAN CN UE configuration data storage CN and RAN CN and RAN CN and RAN NoUP contexts in RAN Yes Yes, but DL packets not sent to RAN Yes, DL packets sent to RAN
  5. 5. INACTIVE STATE IN 5G NR ✱ JUNE 19, 2019 ✱ ERICSSON TECHNOLOGY REVIEW 5 AftertheUEconfigurationissuccessfully retrieved,thetargetnoderesumesthestored configurationattheUEandappliesanynecessary modifications,suchastheconfigurationof measurementsandtheadditionorremovalof bearers.TherespectiveRRCresumemessageis integrityprotectedandencryptedusingthesecurity contextstoredinthenetworkandtheUE. AsillustratedontherightsideofFigure2,the resumeprocedurereducesthenumberofRRC messagesexchangedovertheradiointerface betweentheUEandtheRANtothree(downfrom sevenforidlestate).RRCresumealsohasthe possibilityofusingefficientdeltasignaling–inwhich onlychangedparametersaresignaled–torestore theconfigurationofaUEintheinactivestate.This optionisnotpossibleforUEsintheidlestate. ThereductioninRRCsignalingsignificantly lowerstheaccesslatencyexperiencedbyUEs,which leadstomoreresponsiveend-userserviceandthe abilitytosupportnewusecases.Italsoreducesthe powerconsumptionfordevicessuchasbattery- poweredsensorsthatonlysendsmall,infrequent reports(oftenlessthan100bytesofdata). RAN-basedlocationmanagement andRANpaging Thetransitionfromtheconnectedtotheinactivestate isdesignedtobeinvisibletothe5GCN.Asaresult, evenwhentheUEisintheinactivestate,the5GCN treatsitasthoughitwereintheconnectedstate–that is,theUE-associatedsignalinganduser-data connectionbetweenthe5GCNandtheRAN continues.Mobile-terminatedsignalinganduser- plane(UP)dataissentfromtheCNtotheRANnode currentlyservingtheUE. WhentheservingRANnodereceivessignalingor dataforaUEintheinactivestate,itinitiatesRAN paging.ThepagingisperformedinanRNAthat consistsofoneormorecellsandwasassignedtothe Figure 2 Comparison of signaling involved in legacy idle-to-connected transition (left) versus inactive-to-connected transition (right) LTE/NR RAN Legacy idle-to-connected transition New inactive-to-connected transition NR RANCN CNUEUE RRC connnection request Initial radio synchronization RRC resume request RRC resume RRC resume complete UL/DL user data RRC connection setup RRC connection complete (service request) RRC security setup RRC security complete UL/DL user data RRC reconfiguration (bearer setup) RRC reconfiguration complete Initial UE message (service request) UE context setup (keys, bearers) Initial radio synchronization UE context setup complete Initial radio synchronization
  6. 6. ✱ INACTIVE STATE IN 5G NR 6 ERICSSON TECHNOLOGY REVIEW ✱ JUNE 19, 2019 UEwhenitwasorderedtoentertheinactivestate. WhenaUEintheinactivestatemovestoacellthatis notpartofitscurrentlyassignedRNA,theUE performsalocation-updateprocedurethatenables theRANtoupdatetheassignedRNAtotheUE. Asinearliercellularsystems,thereisatrade-off betweenthepagingloadandtheamountoflocation- updatesignaling.Largerpagingareashavemore pagingloadbutlesslocationupdatesignalingthan smallerpagingareas. Keytechnologyaspects ThemostnotabletechnologyaspectswithintheNR inactivestateconceptadoptedby3GPParesupport forencryptedresponsemessages,smartRANpaging, RANarchitecturesupportandfallbacktolegacy procedure. Supportforencryptedresponsemessages OneofthemaincomponentsdrivenbyEricssoninthe NRinactivestateconceptadoptedin3GPPisthe abilitytoencrypttheresponsemessage(resumeor suspend/release)fromthenetwork.Thisdiffersfrom the4GLTEresumeconceptadoptedinRel-13, wherethismessageisintegrityprotected,butsent unencrypted. Toenabletheencryptioncapability,the3GPP adoptedasolutionproposedbyEricssoninwhich thenetworkprovidestheUEwithasecurity parameterinthereleasemessagetotheinactive state.TheUEusesthesecurityparametertocalculate anewsecuritykeytobeusedwhenitresumes. Theabilitytoencrypttheresumeresponse messagein5GNRisadvantageousbecauseitmakes itpossibletouseasingle,securemessageto: ❭❭ Reconfigure any parameter in the UE when transitioning to the connected state. ❭❭ Release the UE to the idle state (the release message could also include redirection information to another frequency or radio access technology that could be used for voice fallback to LTE, for example). ❭❭ Resuspend the UE to the inactive state when it is performing a location-update procedure, for example, so that it only consumes two messages in total (request and response). SmartRANpaging ForanyUEintheconnectedstate,theRANnode receivespagingassistanceinformationrelatedto potentialpagingtriggers,suchasQoSflowsor signaling,fromthe5GCN.Thisinformation,in combinationwithotherinformationthattheRANhas abouttheUE,canbeusedbytheRANnodetoselect andapplyasmartpagingstrategythatisalignedwith thecharacteristicsandrequirementsoftheUEand paging-triggeringservices. Forexample,theRANcanconfigureUE-specific RNAsthatmakeitpossibletoreducethetotal signalingloadbyconfiguringsmallRNAsfor stationaryUEs(optimizedforlowpagingload)and largerRNAsformovingUEs(optimizedforlow locationupdatesignalingload). Terms and abbreviations AMF – Access and Mobility Function | CA – Carrier Aggregation | CN – Core Network | CP – Control Plane | CU – Central Unit | DC – Dual Connectivity | DL – Downlink | DRX – Discontinuous Reception | DU – Distributed Unit | EDT – Early Data Transmission | E-UTRA – Evolved Universal Terrestrial Radio Access | GNB – GNodeB | IOT – Internet of Things | MAC – Medium Access Control (protocol) | MTC – Machine-type Communication | NB-IOT – Narrowband Internet of Things | NG-RAN – Next-Generation RAN| NR – New Radio | PPP – Public-private Partnership | RNA – RAN Notification Area | RRC – Radio Resource Control | UE – User Equipment | UL – Uplink | UP – User Plane | UPF – User-plane Function
  7. 7. INACTIVE STATE IN 5G NR ✱ JUNE 19, 2019 ✱ ERICSSON TECHNOLOGY REVIEW 7 RANarchitecturesupport TheRANofthe5Gsystem–knownasnext- generationRAN(NG-RAN)–consistsofRAN nodesthatserveeitherEvolvedUniversalTerrestrial RadioAccess(E-UTRA)orNRcells.Thebottom leftcornerofFigure3illustrateshowRANnodes (gNBs)thatserveNRcellscanbesplitintocentral units(CUs)ordistributedunits(DUs).ADUhosts functionsrelatedtolowerradioprotocollayers,while aCUhostsfunctionsrelatedtohigherradioprotocol layers(RRCandServiceDataAdaptationProtocol/ PacketDataConvergenceProtocol).SeveralDUs areconnectedtotheirservingCUnodesviatheF1 interface,whileRANnodesmaybeinterconnected bymeansoftheXninterface.ACUmaybefurther splitintoacontrolplane(CP)part(CU-CP)and severalUPparts(CU-UP). ThefunctionaldecompositionofNG-RANnodes servesamultitudeofdifferentdeploymentoptions, includingthosewhereaCUisdeployedtoservea largenumberofDUscorrespondingtoalarge servingarea.Forexample,theCUwouldbeableto veryefficientlycontrolUEmobilitywhile minimizingsignalingtraffictowardthe5GCNand betweenRANnodes. Withregardtotheinactivestate,theCUwouldbe abletocontroltaskssuchastheassignmentofthe UE’sRNAbasedontheUE’smobilitybehaviorand certainRANtopologyknowledge.Basedon Ericsson’sproposal,boththeCPandUPresources canremainconfiguredintheCUwhentheUEisin theinactivestate.Thebenefitofthisisareductionin processingandsignalingiftheUEreturnstothe sameCU,whichishighlylikelyinthistypeof deployment. Fallbacktolegacyprocedure If,foranyreason,theUEandtheRANendupinan unsynchronizedstateandtheresumeprocedurefails, theUEwillautomaticallyswitchovertothelegacy idle-to-connectedtransitionprocedurethatinvolves CNsignaling.Thissolutioncouldalsobeusefulifthe RANisunabletoretrievetheUEconfigurationor theUEconfigurationhasbeenactivelydiscarded. Figure 3 NG-RAN architecture AMF/UPF gNB gNB-CU- UP E1 Xn NG NGNG NG NGNG Xn Xn F1-C F1-U gNB-DUgNB-DU gNB gNB gNB AMF/UPF 5G CN NG-RAN gNB-CU- CP
  8. 8. ✱ INACTIVE STATE IN 5G NR 8 ERICSSON TECHNOLOGY REVIEW ✱ JUNE 19, 2019 Inthesesituations,thenetworkwillrespondwithan RRCconnectionsetupmessageinsteadofanRRC resumemessagewhentheUEsendstheRRC resumerequest.WhentheUEreceivesthesetup message,itwilldiscardtheoldRAN-relatedUE configurationandproceedaccordingtothelegacy idle-to-connectedprocedure. UEsintheinactivestatewilllistenforbothRAN- andCN-triggeredpaging,sothattheCNisableto makecontactwithinactiveUEsiftheRAN configurationislostordiscarded.Thiscapabilityis alsousefulifaUEhasbeenoutofradiocoverageand missedRANpaging,resultingintheRANnode releasingtheUEconfiguration.ToreduceUE batteryconsumption,thesolutionprovidesa mechanismfortheRANandCNtocoordinatethe pagingoccasions,sothattheUEonlyneedstowake uponcetolistentoboth. Futureenhancements Whiletheessentialcomponentsfortheinactivestate aresupportedinRel-15,thereisanopportunityfor furtherenhancementsoftheNRstandardinlater releases.Thereareseveralusecasesandscenarios thatwouldbenefitfromenhancementstothe applicabilityandefficiencyoftheinactivestate, particularlyintheareasofearlydatatransmission (EDT),earlymeasurementsandlongdiscontinuous reception(DRX). Earlydatatransmission Tomeetthemorestringentrequirementsoffuture 5Gusecases,itwillsoonbenecessarytoreduceUL latencyevenfurther.EDTisafeaturethatwould allowopportunisticdatatransmissiontocommence duringtheconnectionresumeprocedure.Withthe resumeprocedureasspecifiedinRel-15,connection resumeproceduresarecompletedbeforedata transmissioncanstart.WithEDT,datatransfercan begininparallelwithtransmissionoftheresume requestmessageintheULandtheresumemessage inthedownlink(DL).Securityandradiobearersare resumedbeforesubmittingtheresumerequest messagetolowerlayers,whichallowsmultiplexingof datawithsignalingintheMediumAccessControl (MAC)layer. EDThasalreadybeenintroducedinLTE-Mand Narrowband-IoT(NB-IoT),wheretrafficisexpected tocomprisethetransmissionofsmallamountsof dataandoneoftheprimaryobjectivesislongUE batterylife.Forusecaseswheretrafficconsistsof onlyoneULand/oroneDLdatapacket,EDT improvesenergyefficiencybyenablingthenetwork toreleasetheUEtotheinactivestatewithoutthe needforintermediateresumeandresumecomplete messages. Earlymeasurements NRRel-15alreadysupportstheaggregatingof multiplecarriersforhigherdatathroughputusing eithercarrieraggregation(CA)ordualconnectivity (DC).Whentransitioningfromtheinactiveoridle statetoconnectedstate,however,theUEonlyhas accessthroughonecarrier.FastersetupofCAor DCwouldmakeitpossibletofurtherreducethe sessionsetuplatency.However,theusefulnessof CAandDCdependsonthenetworkunderstanding oftheradioenvironment. Earlymeasurementreportingisafeature currentlybeingstandardizedinRel-16toimprove thesetupofCAandDCbyenhancingNRtosupport earlyradiomeasurementreportsduringthe transitionfromtheinactivetoconnectedstate–that is,inparallelwiththeresumecompletemessage. ThiswouldbepossibleinNRbecausewhentheUE issuspended,itreceivesthesecurityparameters neededtoencryptthesensitivemeasurement report.Whensecurityisactivated,early measurementreportscanbemultiplexedwitha resumerequestormultiplexedwitharesume completemessage(ifrequestedbytheRANinthe resumemessage). THECNISABLETOMAKE CONTACTWITHINACTIVEUEs IFTHERANCONFIGURATION ISLOSTORDISCARDED
  9. 9. INACTIVE STATE IN 5G NR ✱ JUNE 19, 2019 ✱ ERICSSON TECHNOLOGY REVIEW 9 Longdiscontinuousreception DRX,afeaturethatenablestheUEtoturnoffits receiver,isimperativeinusecaseswheredevice energyefficiencyandbatterylifeareimportant considerations.Thelongerthetransmitterand receivercanbeturnedoff,themoreenergytheUE cansave(thelongerthebatterylife).LongDRXhas traditionallybeensupportedintheidlestate. Toenjoythebenefitsofbothsignalingreductions andlongDRX,itisdesirabletoextendDRXcyclesin theinactivestatetothesamelengthasDRXcyclesin theidlestate.Akeyaspectoftheinactivestate, however,isthat,fromtheCNpointofview,theUE remainsconnectedandDLdataarrivingtotheCN wouldnormallybeforwardedtotheRANnode servingtheUE.TheRANwouldbufferthedata untiltheUEisreachable. WithshortDRX,theamountofdatathatwould needtobebufferedislimited.WithverylongDRX, however,thebufferingrequirementsintheRAN growandmayexceedwhatisnormallyneeded, whichwouldbecomecostly.Tomitigatethisand makeuseof(alreadyexisting)CNbuffering capability/capacity,theRANmayindicatetotheCN thattheUEisnotavailableforDLdatawhileinthe inactivestate.Inthisevent,theCNwillbufferthe dataandnotifytheRAN,sothattheRANcan informtheCNwhentheUEbecomesavailable again.ItisanticipatedthattheuseoflongDRXinthe inactivestatewithbufferingoffloadedtotheCN wouldfurtherimprovebatterylife,whileenabling efficient(re)useofbufferingcapabilitiesinthe network. Conclusion Improvedconnection,stateandmobilityhandlingare keyrequirementsofmanycurrentandfuture5Guse cases,includingsmarttransportandcriticalcontrolof remotedevices.AtEricsson,our4G/5Gresearch activitiesandlessonslearnedfromlegacynetworks haveenabledustoidentifysolutionsthatsignificantly lowerbothlatencyandbatteryconsumptionby reducingtheamountofsignalingrequiredduring statetransitions.Asaresultofthiswork,the standaloneversionofthe5GNRstandardincludesa newRadioResourceControlstatemodelthatfeatures anewstatecalledinactive. Theinactivestatein5GNRisakeyenablerfor emergingusecasesthatrequirelowlatency communicationandminimalbatteryconsumption. Anadditionalbenefitofthenewstateisthatthe decreasedprocessingeffortinthenetworkresultsin anincreaseinoverallsystemcapacity. Rel-15includesalltheessentialcomponentsfor theinactivestate.Futurereleasesshouldfocuson providingapplicabilityandefficiencyenhancements, particularlyintheareasofearlydatatransmission, earlymeasurementsandlongdiscontinuous reception. References 1. Ericsson, 5G use cases, available at: https://www.ericsson.com/en/5g/use-cases 2. 2016 IEEE International Conference on Communications Workshops (ICC), A novel state model for 5G Radio Access Networks, Da Silva, I.L.; Mildh, G; Säily, M; Hailu, S, abstract available at: https://ieeexplore. ieee.org/document/7503858 3. Ericsson, Handling of inactive UEs, 2016, 3GPP RAN2#94, R2-163998, available at: http://www.3gpp.org/ ftp/TSG_RAN/WG2_RL2/TSGR2_94/Docs/R2-163998.zip 4. 3GPP, TS 38.300, NR; Overall description; Stage-2, available at: https://portal.3gpp.org/desktopmodules/ Specifications/SpecificationDetails.aspx?specificationId=3191 5. 3GPP, TS 38.331, NR; Radio Resource Control (RRC); Protocol specification,available at: https:// portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=3197
  10. 10. ✱ INACTIVE STATE IN 5G NR 10 ERICSSON TECHNOLOGY REVIEW ✱ JUNE 19, 2019 Icaro Leonardo Da Silva ◆ joined Ericsson Research in 2010 and currently serves as a master researcher in radio network architecture and protocols. His work has largely focused on standardization and concept development for LTE and 5G NR, and in particular on CP topics in 3GPP RAN2, for which he was awarded the Inventor of the Year prize for 2018. Da Silva led the 5G CP in the EU project on 5G RAN architecture, METIS- II, which is part of the 5G-PPP framework. He holds an M.Sc. in electrical engineering from the Federal University of Ceará (UFC), in Fortaleza, Brazil. Gunnar Mildh ◆ is an expert in radio network architecture in the Network Architecture and Protocols department at Ericsson Research. He joined the company in 2000 and has worked on standardization and concept development for GSM/EDGE, HSPA, LTE(-A) and 5G NR. His focus areas include radio network architecture and protocols, and more recently 5G architecture including RAN and Packet Core. Mildh holds an M.Sc. in electrical engineering from KTH Royal Institute of Technology, Stockholm, Sweden. Paul Schliwa- Bertling ◆ joined Ericsson in 1996 and currently serves as an expert in mobile networks architecture and signaling at Ericsson Research in Linköping, Sweden. He has worked extensively with the development of RAN product and system-level concepts as well as 3GPP standardization across multiple generations of RAN and CN. His current work focuses on the evolution of network architecture and the related signaling aspects contributing to 3GPP standardization. He holds an M.Sc. in electrical engineering from the University of Duisburg- Essen in Germany. Magnus Stattin ◆ joined Ericsson Research in 2005, where he currently serves as a principal researcher. Over the years his work has focused on research in the areas of radio resource management and radio protocols of various wireless technologies. He is also active in concept development and 3GPP standardization of LTE, NB-IoT, NR and future wireless technologies. Stattin holds a Ph.D. in radio communication systems from KTH Royal Institute of Technology in Stockholm. Alexander Vesely ◆ joined Ericsson in 2013 after working at other major mobile network vendors for more than 20 years. He currently serves as the company’s principal researcher for standardization. He has also held offices in the 3GPP for approximately eight years, and is still actively contributing. Vesely holds a Dipl.Ing. in communications engineering from the Technical University in Vienna, Austria. theauthors
  11. 11. ISSN 0014-0171 284 23-3330 | Uen © Ericsson AB 2019 Ericsson SE-164 83 Stockholm, Sweden Phone: +46 10 719 0000

×