6/15/2021MMEFunctionsMME51-MME511510SGiseratorsPDNServingUEE-UTRANGatewayGatewayIMS,PSSetc51-ULTE-UUO·Handling of NAS signaling-En/decryption and authentication ofmessages·Support ofUEReachability inidle”state.TrackingAreamanagement;·PDN/S-GWselection.TargetMMEselection·Subscriberauthentication?Bearermanagement? Lawful Interception of signaling traffic@TarikTALEB202131Evolved RANeMME51-MMES11510SGIateSPDNServingUELE-UTRANGatewayGatewayne.g. IM5,PSSetc.S1-UeeaLTE-UU·RadioResourceManagement-RadioBearerControl-RadioAdmissionControl-Connection Mobility Control10t-Scheduling·IPheadercompression and encryption of datatrafficeNeNB·MMEselectiontheuserdatastream·Data packetrouting.Uplink transport level packetmarking?Scheduling and transmission of-pagingmessages-broadcastinformation? Measurementformobility and scheduling@TarikTALEB20213216
6/15/2021 16 MME Functions SGi S1-MME Operator's IP Services (e.g. IMS, PSS etc.) S10 UE LTE-Uu S11 Serving S5 Gateway PDN Gateway S1-U MME E-UTRAN Control Plane Data Plane • Handling of NAS signaling - En/decryption and authentication of messages • Support of UE Reachability in “idle” state • Tracking Area management; • PDN/S-GW selection • Target MME selection • Subscriber authentication • Bearer management • Lawful Interception of signaling traffic © Tarik TALEB 2021 Evolved RAN SGi S1-MME Operator's IP Services (e.g. IMS, PSS etc.) S10 UE LTE-Uu S11 Serving S5 Gateway PDN Gateway S1-U MME E-UTRAN Control Plane Data Plane X2 eNB eNB UTRAN Iub Iub NB NB RNC Iups • Radio Resource Management - Radio Bearer Control - Radio Admission Control - Connection Mobility Control - Scheduling • IP header compression and encryption of data traffic • MME selection the user data stream • Data packet routing • Uplink transport level packet marking • Scheduling and transmission of - paging messages - broadcast information • Measurement for mobility and scheduling © Tarik TALEB 2021 31 32
6/15/2021Tracking Areas, Service Areas, & MME PoolAreasMMEPoolAreaoPDN-GW1PDN-GWm口S-GWDS-GW2S-GWkService AreaService Area 2Service Area K国园.园园园园园eNBseNBseNBseNBsTracking Area NTrackingArea3Tracking AreaTracking Area 2TrackingAreaUpdateS-GW RelocationMME Relocation@Tarik TALEB202133LTEUEIdentifiersUE-IMEIorMEID-MobileEquipmentIdentifierGloballyuniquenumberidentifyingaphysicalpieceofmobilestationequipmentMEIDallowshexadecimal digitswhile IMEI (IntIMobileStationEquipmentldentity)allowsonlydecimaldigitsOnly sent to MME (in NAS), not to eNB·SentonlyafterNAS security is setup (i.e,encrypted and integrityprotected).SIM(SubscriberIdentityModule)-HD:UniversalIntegratedCircuitCard(UICC)-SW:USiM-UniversalSubscriberIdentityModule.IMSISeldom sent over the air (only during attach, if no other valid temporary IDis present in the UE),Temporary identities used instead (S-TMSI, GUTI)Brought,among otherthings,security improvements (e.g.,mutualauthentication,longerencryptionkeys,etc)S-TMSISystem architecture evolution Temporary Mobile Subscriber Idenity@TarikTALEB2021GUTIGlobally Unique Temporary ldentity3417
6/15/2021 17 Tracking Areas, Service Areas, & MME Pool Areas © Tarik TALEB 2021 eNBs Tracking Area eNBs Tracking Area 2 eNBs Tracking Area 3 eNBs Tracking Area N Service Area 1 Service Area 2 Service Area K PDN-GW 1 S-GW 1 S-GW 2 S-GW k PDN-GW m MME MME Pool Area Tracking Area Update S-GW Relocation MME Relocation LTE UE Identifiers © Tarik TALEB 2021 • UE – IMEI or MEID - Mobile Equipment Identifier • Globally unique number identifying a physical piece of mobile station equipment • MEID allows hexadecimal digits while IMEI (Int’l Mobile Station Equipment Identity) allows only decimal digits • Only sent to MME (in NAS), not to eNB. • Sent only after NAS security is setup (i.e, encrypted and integrity protected). • SIM (Subscriber Identity Module) – HD: Universal Integrated Circuit Card (UICC) – SW: USIM – Universal Subscriber Identity Module • IMSI – Seldom sent over the air (only during attach, if no other valid temporary ID is present in the UE). – Temporary identities used instead (S-TMSI, GUTI) • Brought, among other things, security improvements (e.g., mutual authentication, longer encryption keys, etc) S-TMSI System architecture evolution Temporary Mobile Subscriber Identity GUTI Globally Unique Temporary Identity 33 34