WiFi Integrationin Evolution to 5G networksSatish Kanugovi ([email protected])WiFi Knowledge Summit, BangaloreMarch 9, 20181 Nokia 2018
Outline Integrating WiFi Access into the 5G Core Multi-Access Edge Computing and WiFi Access Common Capacity Management Frameworks- IETF - Multi Access Management Services (MAMS)- 3GPP – Access Traffic Steering, Switching and Splitting (ATSSS)
Integrating WiFi Access into the 5G Core Non-3GPP access networks are connected to 5G core network via a Non-3GPP InterWorking Function (N3IWF). The N3IWF interfaces to 5G core network control-plane functions and user-planefunctions via N2 interface and N3 interface, respectively. Only Untrusted Non 3GPP Access is currently in scope, Trusted being discussed for a NetworkUPFN3N6Y2Non-3GPPNetworksUntrusted Non3GPP AccessUEY1Non-roaming architecture for 5G core network with non-3GPP accessSource: 3GPP TS 23.501
5G Control Plane for WiFi Access UE gets an IP address via the non-3GPP access. UE initates IPsec Security Association (SA) withthe selected N3IWF by initiating an IKE initialexchange UE initiates an IKE AUTH exchange indicating theuse of EAP (EAP-5G) signalling. The N3IWF responds with an IKE AUTH responsemessage which includes an EAP-Request/5GStart packet and informs UE to encapsulatedNAS messages within EAP-5G packets. Once the IPsec SA is established between the UEand N3IWF, "signalling IPsec SA“, all NASmessages between the UE and N3IWF areexchanged via this werlayersNon-3GPPUntrusted non-3GPPaccess ontrol Plane before the signalling IPsec SA is established between UE and N3IWFSource: 3GPP TS 23.501NASNASIPsecIPsecIPIPNon-3GPPUntrusted non-3GPPaccess owerlayersAMFN3IWFNwuN2Control Plane after the signalling IPsec SA is established between UE and N3IWFSource: 3GPP TS erlayersUntrusted non-3GPPaccess networkN2stackLowerlayersAMFN3IWFNwuControl Plane for establishment of user-plane via N3IWFSource: 3GPP TS 23.501N2
5G User plane for WiFi Access Data, 5G PDUs, over the Non 3GPPaccess is sent inside the secure tunnelbetween UE and N3IWF UDP can be used as tunnelling protocolin IPsec for NAT traversal.PDULayerPDU LayerGRE ersUntrusted non-3GPPaccess sN3IWFNwuN3UPFUser Plane for Non 3GPP Access via N3IWFSource: Figure 8.3.2-1, 3GPP TS 23.501N9UPF(PDUSessionAnchor)
Edge Computing –“Mobile” to “Multi Access” ETSI MEC is working on standardsfor enabling benefits of EdgeComputing framework toapplications In Phase 1, MEC (Mobile EdgeComputing) focused on EdgeComputing framework for Mobile(cellular) networks In Phase 2, Scope has evolvedinto a Multi Access EdgeComputing Platform with support3GPP and non-3GPP accesstechnologies (WiFi and fixed)Overview of Multi Access Edge Computing 
Extending MEC to WiFi networks ETSI MEC Phase 1 has published Radio Network Information Service (RNIS) APIs forApplications take advantage of real time radio network information to improveservice delivery-http://www.etsi.org/deliver/etsi gs/MEC/001 099/012/01.01.01 60/gs MEC012v010101p.pdf-MEC applies Analytics (e.g. Mashup) on information coming from multiple RATs and provide feedback (e.g. ETSI RNIS APIs) in a way suitable for use byapplications-Can be easily extended to support information exposure from additional RATs, like Wi-Fi, 5G, DSL, individually or in combination. ETSI MEC Phase 2 will extend the information exposure to other access technologies New Service to specify WiFi access information. Some examples of nature ofinformation that could be exposed:-BSS Load (station count, channel utilization, admission capacity)-STA statistics (STA counters, BSS avg delay, etc)-Estimated throughput UL/DL-WAN metrics (DL speed/load, UL speed/load)-STA RSSI Builds on existing and ongoing work from WFA e.g. Multi-AP Services, Data Elementsand Hotspot 2.0.
WiFi Cellular – Common Capacity Management Application QoE (quality of experience) varies with choice of access technology Performance depends on factors like radio conditions, user population, actual networkutilization Wi-Fi offers good capacity with small number of users which quickly degrades, lowthroughputs and large unpredictable delays due to poor MAC efficiency. LTE offers predictable performance but capacity is limited by available licensedspectrum Combining the best of WiFi and Cellular can deliver the best value from the network
IETF MAMS MAMS (Multi Access Management Services) is a framework for-Integrating different access network domains based on user plane (e.g. IP layer) interworking,with ability to select access and core network paths independentlyand user plane treatment based on traffic typesthat can dynamically adapt to changing network conditionsbased on negotiation between client and network The technical content is available as the following drafts*- Multi Access Management Services (MAMS) Framework – area-mams-framework/- MAMS JSON definitions of Control Plane Messages: protocol-json-00.txt- MAMS User Plane Specification: -user-protocol-02*Currently under review, Co-authors: Nokia, Intel, Broadcom, Huawei, AT&T, KT,
MAMS Architectural Framework MAMS functional elements- Network Connection Manager (NCM) APPLICATIONSERVERIntelligence in the network to configure network paths and user planeprotocols based on client negotiationMAMS Enabled NetworkGateway for common multi-network view, network policy input andInterface to Application PlatformsCore User PlaneGatewayCORE NETWORKS- Client Connection Manager (CCM) Negotiates client’s capabilities and needs with the NCM andconfigures network path usage- NCM – CCM message exchange enables Dynamic selection of best network paths Flexible configuration of MADP protocols and parameters Overlay and Extensible messaging (e.g. JSON over WebSocket)- Multiple Access Data Proxy (C/N-MADP) C-MADP handles user plane functions at the client and N-MADP atnetwork. User plane distribution and aggregation across configured networkpaths. DSL/FIXEDCORESupports any user plane protocols including existing IETF protocolslike TCP, UDP, MPTCP, SCTP, QUIC, GRE, (multiple)NCM and NMADPinstancescan behosted atAccess Edgeand/or MADP)NETWORKCONNECTIONMANAGER(NCM)LTE CORE5G COREMEC(Access Edge)ACCESS NETWORKSMAMSControl PlaneMAMSUser PlaneDSL/FIXEDACCESS NODE(ROUTER)WI-FI NAGER(CCM)CLIENTMULTIACCESSDATAPROXY(C-MADP)LTE ACCESSNETWORK (ENB)5G(GNB)
MAMS at MEC integrating LTE and Wi-Fi networksUse case 1: Support high UL/DL BW applications with LTE  Applications accessed via LTE core (cellularservice subscription and authentication) cantake advantage of Wi-Fi capacity in uplinkand downlinkAPPLICATIONSERVERCORE NETWORKSWLANCORE Flexibility in choosing Wi-Fi access evenwhen LTE core is used as IP anchor Support high bandwidth demanding videodownloads on LTE connections using Wi-FiDL Support LTE Core routed cloud videocontent uploads using Wi-Fi UL MEC controls and monitors usage of Wi-FiaccessLTE COREMEC(NCM)(N-MADP)ACCESS NETWORKSWI-FI ACCESSNETWORK(ACCESS POINT)LTE ACCESSNETWORK (ENB)CLIENTCLIENTCONNECTIONMANAGER(CCM)CLIENT MULTIACCESS DATAPROXY(C-MADP)
MAMS at MEC integrating LTE and Wi-Fi networksUse Case 2: Using LTE UL to improve QoE for ‘Wi-Fi’ Apps  Enterprise improves its services by offloadingUplink of Enterprise services to LTE uplink thatare then shunted across back to the enterpriseWLAN infrastructureAPPLICATIONSERVERCORE NETWORKSWLANCORE All enterprise traffic stays local – avoids traversalthrough operator coreMEC ‘Big’ gains in VoWiFi capacity Simple, scalable solution towards all-wirelessenterprise that leverages LTELTE CORE(NCM)(N-MADP)ACCESS NETWORKSWI-FI ACCESSNETWORK(ACCESS POINT)LTE ACCESSNETWORK (ENB)- Internet access possible through enterprise coreCLIENTCLIENTCONNECTIONMANAGER(CCM)CLIENT MULTIACCESS DATAPROXY(C-MADP)
3GPP Access Traffic Steering, Switching and Splitting (ATSSS) 3GPP TR 23.793 has in its scope the study of architectural aspects and solutions forextending the 5G System (5GS) to support Access Traffic Steering, Switching andSplitting (ATSSS) between 3GPP and non-3GPP access networks. Initially, the study considers ATSSS solutions that enable traffic selection, switching andsplitting between NG-RAN and untrusted non-3GPP access networks. Subsequently, after the 5GS architecture is enhanced to support trusted non-3GPPaccess networks.
Proposed Solutions in ATSSS TR 23.793 (0.2.0, work in progress)N13UDR -AT3SFAUSFUDMN25N3NG-RANN2N113GPPAccessSM -AT3SFAMFN7PC -AT3SFSMFN5N15UP -AT3SFN3N1UE NChild PDUsession #2N9N3IWFN3UPF-2(optional)ANSolution 2: Support of Multi-Access PDU SessionsUntrusted Non 3GPP AccessUEWLANN2Child PDUsession 14N2N3Multi-AccessPDU sessionUEN10N8N12PCFY1ATSSS Policy Control functionSolution 1: Proposed architecture framework for ATSSSTraffic Steering Switching & Splitting policiesSMFUEATSSS Policy Enforcement functionControl planeTraffic Steering Switching & Splitting rulesN4User planeUPFPDU session dataATSSS TrafficControl functionPDU session dataPath performance measurementLink detectionNCPEncapsulationTraffic Distribution function3GPP accessNCPDecapsulationTraffic Recombination functionNon-3GPP accessPath performance measurementN3N3Traffic RecombinationfunctionTraffic Distribution functionATSSS TrafficControl functionNCPDecapsulationNCPEncapsulationSolution 3: NCP based architecture framework for ATSSSN6
ReferencesMEC Introduction Slides, ETSI MEC MEC Deployments in 4G and Evolution Towards 5G, ETSI MEC Whitepaper 3GPP TS 23.501, System Architecture for the 5G System; Stage 2 (R15) 3GPP TS 23.502, Procedures for the 5G System; Stage 2 (R15) 3GPP TR 23.793, Study on Access Traffic Steering, Switching andSplitting support in the 5G system architecture (R16) IETF MAMS Framework draft (under review) - framework-00.txt MAMS (Multi Access Management Services) framework for MEC, Broadband ForumBirds of a Feather Webinar - MEC Part 2, BBF2017.556
MAMS (Multi Access Management Services) is a framework for - Integrating different access network domains based on user plane (e.g. IP layer) interworking, - with ability to select access and core network paths independently - and user plane treatment based on traffic types - that can dynamically adapt to changing network conditions