Next-Generation Mobile Networks: 3GPP Evolved Packet System and Femtocell Technologies Dr. Stefan Schmid Manager, Next Generation Networking Group NEC Laboratories Europe Heidelberg, Germany (stefan.schmid@neclab.eu) Keynote at IWCMC'09, Leipzig, Germany, June 2009
Outline A Historic Retrospect on the Evolved Packet System How it all began The big vision Architecture study and battles The reality of standards Overview and Status of Evolved Packet System What could finally be achieved Core Principles Basic functionalities/capabilities Limitations Open Issues and Future Work IP Flow Mobility Localized Routing Prospects of Femtocell Technologies Is it just a hype? Conclusions 2 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
A Historic Retrospect From the initial Vision to a Standard
Once upon the time How it all began Some researchers and standards folks had a VISION The mobile industry engaged into the endeavor to study the evolution of the mobile network system 3GPP System Architecture TSG started a Feasibility Study in SA1 on All IP Networks 2004 2005 2006 2007 2008 2009 2010 2011 4 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
Motivations and Drivers (1/2) There seems to be a common understanding in the mobile communications industry that the technical and commercial evolution of this industry sector points towards an AIPN. User related and social drivers: affordable high-speed mobile access support of diverse mobile network services seamless service experience across access technologies ability to obtain low-cost low-end services and high priced high-end services 5 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
Motivations and Drivers (2/2) Drivers from a Business perspective: handle large volumes of IP traffic in a cost effective manner support user-to-user and user-to-multicast traffic incorporate non-3gpp access technologies with minimum impact interworking with other networks (considering mobility, security, charging and QoS) account for fixed/mobile convergence issues Drivers from a Technology perspective significantly higher data rates to end-users multiple radio access systems 6 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
The All-IP Network Vision PSTN External IP Networks e.g. Internet Session management Common IPbased network Security and Privacy functionality Enhanced Services AIPN Support of a variety of Different access technologies QoS Enhanced network performance Advanced mobility management Terminal and User identification Network extensibility composition End to End QoS Guaranteed Connection I-WLAN Future Radio Access Systems Existing 3GPP access technologies Other Accesses Terminalmobility Session mobility 7 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
The BIG Vision... New and enhanced Services Common IPbased Network Multi-Access Security & Privacy Terminal Mobility Self- Management Machine-tomachine Network Composition Personal Area Networks Session Mobility QoS Support Moving Networks 8 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
From the Vision to a Standard Feasibility study (TR 22.978) concluded with the All-IP Networks vision and recommended normative work SA1 continued and standardized the Service Requirements for the All-IP Network (TS 22.258) Radio Access WGs in 3GPP started with a long-term evolution of the 3GPP Radio Access Network LTE (Long-Term Evolution) == E-UTRAN (Evolved UTRAN) System Architecture Evolution work for the 3GPP Evolved Packet Core started (TR 23.882) SAE (System Architecture Evolution) == EPC (Evolved Packet Core) Start of All IP Networks Study 2004 2005 2006 2007 2008 2009 2010 2011 TR: Technical Report TS: Technical Specification 9 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
System Architecture Study Objectives: address architecture impacts stemming from All-IP Network study (TR 22.978) define Evolved Packet Core (EPC) for LTE support mobility between heterogeneous access networks, including service continuity Architecture work was taken very seriously by the industry number of people involved increased noticeably (just in the meeting 100-150 people for SAE) politics of stakeholders interests came into play 10 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
The Reality of Standards Interworking with Legacy Other Standards Actual service needs Time constraints Vendor Interests 11 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009 Time pressure
Architecture Battles Example 1 GERAN UTRAN Layer-2 like Evolved RAN Iu Gb R1 AAA interface HSS WLAN 3GPP IP Access SGSN Gn/Gp Gx+ Evolved Packet Core R2 Architecture A PCRF1 Gi Based on IPbased Mobility Protocols (IETFbased) Gi Op. IP Serv. (IMS, PSS, etc ) Architecture B Op. IP Serv. (IMS, PSS, etc ) Internet Gi Internet Mobility between access networks Wi based on 3GPP protocols (e.g. GTP) Gi+ Inter-AS AS MM MM Gi+ Gi GPRS Core PCRF2 Wi+ HSS Internet Gb Iu WLAN 3GPP IP Access May 2005 GERAN UTRAN Layer-3 like AAA interface Evolved Evolved Packet Core Evolved RAN Access Gi Wi Gi 12 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
Architecture Battles Example 2 SGi December 2006 Mobility hsae GW Anchor GTP vs. IP-based Mobility HPLMN VPLMN S8a (GTP) SGi S8b (PMIP) S2a/b (PMIP) legacy PMIP: Proxy Mobile IP GTP: GPRS Tunneling Protocol vsae GW MME UPE S2a/b non-3gpp S5 (GTP or PMIP) 13 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
Architecture Battles Example 2 The Compromise Proposal SGi hsae GW December 2006 HPLMN S2a/b (PMIP) VPLMN S8a (GTP) SGi S8b (PMIP) legacy PMIP: Proxy Mobile IP GTP: GPRS Tunneling Protocol vsae GW MME UPE S2a/b non-3gpp S5 (GTP or PMIP) 14 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
From the BIG vision to the small reality From a Core Network perspective, the All IP Network vision resulted primarily: GPRS Enhancement for E-UTRAN (TS 23.401) Architecture enhancements for non-3gpp accesses (TS 23.402) Conclusion of Architecture Study and start of normative Standardisation work for EPC Start of All IP Networks Study Start of Architecture Study 2004 2005 2006 2007 2008 2009 2010 2011 15 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
First Release of Evolved Packet System (EPS) First release of Evolved UTRAN + Evolved Packet Core = Evolved Packet System was standardized in 3GPP Release 8 Official freeze of architecture work for Rel-8 was in June 2008 Start of All IP Networks Study Start of Architecture Study Start of Normative Work 2004 2005 2006 2007 2008 2009 2010 2011 16 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
Rel-8 EPC ~ Rel-9 EPC Not surprisingly, 1 st release required a lot of bug-fixing to make it finally work Until freezing date of Rel-9 (June 2009), many essential corrections and enhancements had to be done still for Rel-8 Rel-9 is with few exception identical to Rel-8 Start of All IP Networks Study Start of Architecture Study Start of Normative Work Official architecture freeze for Rel-8 2004 2005 2006 2007 2008 2009 2010 2011 17 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
Mission accomplished?!? NEC s target for the Evolved Packet System (from 2006) PSTN VoIP NW Corporate IMS Internet Evolved Packet Core SAE GW SAE GW agw/ epdg GPRS xgsn MME/UPE epdg ASN-GW WiMAX DSL/Cable Modem GERAN UTRAN LTE WLAN 18 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
Mission accomplished?!? Finally achieved solution PSTN VoIP NW Corporate Evolved Packet Core (EPC) PDN GW IMS PDN GW Internet agw/ epdg GPRS MME S-GW epdg agw SGSN WiMAX DSL/Cable Modem GERAN UTRAN LTE WLAN 19 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
NEC s Objectives Objective 1: Evolve the 3GPP System towards a Common PS Core for any type of access system NEC s vision is to target the EPC as the common core for WiMAX, CDMA2000, TISPAN, i.e. any future NG(M)Ns With IMS (together with all its features) as the common service platform for both fixed and mobile networks Objective 2: Allow smooth and timely migration from existing GPRS Core Network according to each operator s needs Flexible architecture needed in order to account for diverse operator requirements (e.g. support a standalone PDN-GW) EPC should allow easy accommodation of current systems the burden for interworking should be on the new system But at a high price! 20 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
NEC s Architectural Principles Principle 1: Aim for common, access-independent protocols for authentication, mobility management, etc. Key for a common packet core for future NG(M)Ns Enables easy accommodation of any new (radio) access systems ( future proof) Principle 2: Offer seamless mobility among heterogeneous access systems, i.e., WCDMA, LTE, CDMA2000, W-LAN, WiMAX, etc. Enable operators to deploy or integrate new/different access networks Allow operators to maximize their coverage and always offer best access speeds to their subscribers Principle 3: Define a new, access-independent roaming interface Convergence towards a common roaming interfaces for different SDOs (a single roaming interface) Harmonization achieves cost reduction and allows for new, converged services across domains 21 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
The Evolved Packet Core Current Status and Business Prospects
Evolved Packet Core Basic Principles EPC Architecture for 3GPP accesses for non-3gpp accesses Current Limitations New Functionalities Expected Deployments of LTE/EPC 23 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
Basic Principles EPS designed to be purely a packet switched system IMS targeted as voice service platform EPS for 3GPP accesses similar to GPRS Core, but more flat Reduction of nodes in user plane path: 4 3 nodes GTP remains main protocol for 3GPP accesses EPS enables interworking with non-3gpp accesses (WLAN, WiMAX, CDMA2000, ) IP Mobility between 3GPP accesses and non-3gpp accesses based on PMIPv6 (Proxy Mobile IPv6) or DSMIPv6 (Dual-Stack Mobile IPv6) 24 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
EPS for 3GPP Accesses PDN GW: IP address allocation, charging and enforces QoS Serving GW: Local mobility anchor for intra-3gpp HO MME: Mobility management entity for intra-3gpp mobility, paging, authentication, bearer management, etc. PCRF: QoS and charging rule provisioning VPLMN HPLMN UTRAN 3GPP Access GERAN S1-MME SGSN MME S3 S4 S12 S6a Gx HSS PCRF Rx UE LTE-Uu E-UTRAN S1-U S10 S11 Serving Gateway S5 PDN Gateway SGi Operator's IP Services (e.g. IMS, PSS etc.) GTP Interface GTP or PMIP Interface PCC Interface 25 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
EPS for non-3gpp Accesses Serving GW: Bearer binding PDN GW: Inter-access system mobility anchor epdg: Security GW for untrusted acesses HPLMN 3GPP Access S6a Serving Gateway (MAG, BBERF) S5 No No GTP GTP bearers, bearers! only PMIPv6 tunnels HSS Gxc Gx PDN Gateway (LMA, PCEF) S2b S2a PCRF Gxa epdg (MAG) SGi SWn Rx SWx Operator's IP Services (e.g. IMS, Internet) S6b SWm 3GPP AAA Server Non-3GPP Networks PMIP Interface PCC Interface AAA Interface A-GW (MAG, BBERF) Trusted Non- 3GPP Access SWu Untrusted Non-3GPP Access UE SWa STa 26 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
Current Limitations No dynamic QoS control for un-trusted non-3gpp accesses No optimized Handover between 3GPP and WiMAX accesses For operators without IMS, voice calls handled in legacy access networks CS Fallback (UE falls back to 2G/3G to carry out voice calls) For legacy access networks without IMS/PS voice support, IMS voice calls need to be translated into CS voice during HO from LTE to 2G/3G Single Radio Voice Call Continuity (IMS voice CS voice) 27 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
Inter-Access System Handover UE Non-3GPP Access GW Serving GW PDN GW PCRF 3GPP AAA Server / HSS IMS Default Access Bearer VoIP Access Bearer PMIPv6 Tunnel IP Connectivity 1. UE discovers and decides to attach to non-3gpp Access 2. Attach 3. Access Authentication 3. Authentication and Authorization 3GPP access non-3gpp access 5. Preparation of QoS Bearers 4. QoS Setup 6. Proxy Binding Update 9. L3 Attach Completion 8. Proxy Binding Ack 7. PCRF update due to RAT change Default Bearer VoIP Bearer PMIPv6 Tunnel IP Connectivity 28 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
Access Network Discovery and Selection Function (ANDSF) ANDSF provides to mobile terminals: 1. Access network discovery information: a list of access networks available in the vicinity of the terminal ` 2. Inter-system mobility policies: rules that help the mobile terminal to (i) decide when inter-system mobility is allowed (ii) select the most preferable access technology or network S14 H-ANDSF Supports both information pull and push modes Information/policies provided are fully operator configurable UE 3GPP IP Access or Trusted/Untrusted Non-3GPP IP Access S14 HPLMN VPLMN V-ANDSF 29 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
Overall Evolved 3GPP System Example based on NEC Products Service & Applications Internet Applications SDP IMS HSS Evolved Packet Core Firewall DNS PCRF S/P-GW S/P-GW MME Transport & Backhaul To other networks Border GW L2/L3 SW Router Aggregation SW Evolved Radio Access Micro wave transport / Optical LTE Femto enb User Terminals Terminals 30 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
Expected Deployments Majority of mobile operators are strongly committed to deploy LTE and EPC as their Next Generation Mobile Network Incl. most 3GPP2 operators (e.g. Verizon, KDDI, ) Source: ZTE TECHNOLOGIES, vol. 11, no. 2, 2009 31 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
Open Issues and Future Work Opportunities for further research
Open Issues and Future Work Ongoing Developments (to be completed in Rel-9) PDN access from multiple interfaces Emergency Communications Future Work IP Flow mobility Localized routing Seamless dual radio handover Local IP Access from Base Station (NB) 33 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
IP Flow Mobility Main Objectives: Enable dynamically routing of IP flows over specific access networks User and/or operator controlled Proposed Solutions: Network based Mobility (PMIPv6) Enables operator control Requires out-of-band signalling between Mobile Terminal and NW Client Mobile IP (DSMIPv6) Limited to user control 3GPP Access Non-3GPP Access UE U EPC/IWLAN Mob IP Flow 1 (e.g. media sync) IP Flow 2 (e.g. VT1) IP Flow 3 (e.g. VT2) IP Flow 4 (e.g. p2p download) IP Flow 5 (e.g. IPTV) Flows from same application (e.g. Benefits: Flexible flow distribution Load balancing / bandwidth aggregation Facilitates resilience 3GPP Access UE U EPC/IWLAN Mob Current Status: Feasibility study started Target Release: Rel-10 Non-3GPP Access IP Flow 1 (e.g. media sync) IP Flow 2 (e.g. VT1) IP Flow 3 (e.g. VT2) IP Flow 4 (e.g. p2p download) IP Flow 5 (e.g. IPTV) Flows from same application (e.g. 34 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
Localized Routing Problem Statement: Current PMIPv6-based EPC architecture tunnels all user-plane through the PDN GW (Local Mobility Anchor) Highly inefficient use of core network resources Scalability issues at PDN GWs Solution: PMIPv6 Localized Routing allows use of a direct routes between mobile terminals Serving GWs User A s Mobility Anchor Access Authentication Mobility Session Authorization Address Delegation PDN GW (LMA) Forwarding Load Sub-optimal path Offload traffic!!! AAA Server User B s Mobility Anchor PDN GW (LMA) Forwarding Load Benefits: Avoid unnecessary waste of core network resources ( efficient transport) Enables traffic offload at PDN GWs ( increase scalability) Reduce of end-to-end delay Serving GW (MAG) Localized Routing Path Serving GW (MAG) Status: Ongoing work in IETF WG NetExt draft-liebsch-netext-pmipv6-ro-ps- 00.txt User A User B Mobile A Communication Mobile B 35 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
Seamless Mobility for Dual-Radio Handover Problem Statement: Current PMIPv6 lacks support for seamless dual-radio handover Why? Downlink path switch is triggered before radio+access bearer setup is completed undesirable delay and jitter Solution: PMIPv6 Transient Binding extension (allows completion of radio+access bearer setup in target access before path switch) Benefits: Low complexity (extension of PMIPv6) Enables seamless mobility for dual-radio handovers Enhances user experience Status: Ongoing work in IETF WG MIPSHOP draft-ietf-mipshop-transient-bcepmipv6-03.txt soon ready 36 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
Prospect of Femtocell Technologies Is it just a hype?
Introduction What are Femtocells? low power access points in licensed spectrum high speed access (HSPA/LTE) cost-efficient backhaul (via customers own DSL, cable, ) extension of mobile operator macro cell coverage with full operator management self-organising, self-managing, etc. at low prices Where are they deployed? Residential Enterprise Hot spot Residential Femto Network Architecture Source: S. Saunders, Chairman of Femto Forum 38 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
7 Reasons why Femtocell Technology expected to be successful 1. High spectrum efficiency Small cell size, less interference, few users 2. Seamless user experience Same terminal, same radio, same service as in macro network 3. Support for legacy terminals User benefits without need to buy new terminals 4. Cost-efficient solution for operators to provide coverage inside buildings Increase coverage depth in buildings through macro cell is very costly 5. WiFi-like solution for high-speed network access at home and in hot-spots Customer operates equipment, support for LIPA, little impact on MO NW 6. Opportunity for Mobile Operator to offer services in the customer's home A portal to home-based services and automation and also new converged services possible 7. Allow for interesting new, location based services Great opportunity for new services based on mobile presence in the home (e.g. child-tracking, mobile advertisement, ) 39 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
Open Issues and Future Topics Open Issues (already under investigation): Seamless hand-in (handover from macro to femtocell) Still to be resolved as part of 3GPP Rel-9 Local (IP Internet) Access (LIPA) Currently be for 3GPP Rel-10 IMS-based Femtocells Hot topic in Femto Forum and 3GPP Rel-10 Femtozone Services Enabling new types of home services Hot topic in Femto Forum Future Topics (opportunity for further research): Femtocells based on LTE-Advanced Networks of Femtocell for Enterprises and public places (e.g. airport, mall, ) Outdoor Femtocells (e.g. stadium, city center, ) Mesh-based Femtocell Networks (wireless backhaul) Mobile Femtocells (e.g. on bus or trains) 40 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
Conclusions First release of Evolved Packet System standardized in 3GPP Rel-8 4+ years from the AIPN vision to the 1 st release of the 3GPP Evolved Packet System standard only key aspects of original vision made it into final standard ( still scope for innovation) Mobile industry highly committed to deploy Evolved Packet System LTE is THE next-generation radio access for mobile operators Still a lot of scope for optimization and enhancements flow mobility localized routing handover optimization etc. Femtocell technology has a lot of potential Current hot topic across the industry Scope for innovation (networked femtos, mobile femtos, ) 41 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009
42 Keynote on "Next-Generation Mobile Networks" at IWCMC'09, Leipzig, June 2009