3GPP TS V ( )

Transcription

1 TS V ( ) Technical Specification 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access (Release 10) The present document has been developed within the 3rd Generation Partnership Project ( TM ) and may be further elaborated for the purposes of. The present document has not been subject to any approval process by the Organizational Partners and shall not be implemented. This Specification is provided for future development work within only. The Organizational Partners accept no liability for any use of this Specification. Specifications and reports for implementation of the TM system should be obtained via the Organizational Partners' Publications Offices.

2 2 TS V ( ) Keywords LTE, GSM, UMTS, GPRS, architecture, stage 2 Postal address support office address 650 Route des Lucioles - Sophia Antipolis Valbonne - FRANCE Tel.: Fax: Internet Copyright Notification No part may be reproduced except as authorized by written permission. The copyright and the foregoing restriction extend to reproduction in all media. 2011, Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC). All rights reserved. UMTS is a Trade Mark of ETSI registered for the benefit of its members is a Trade Mark of ETSI registered for the benefit of its Members and of the Organizational Partners LTE is a Trade Mark of ETSI currently being registered for the benefit of its Members and of the Organizational Partners GSM and the GSM logo are registered and owned by the GSM Association

3 3 TS V ( ) Contents Foreword Scope References Definitions and abbreviations Definitions Abbreviations Architecture model and concepts General concepts Architecture reference model Non-roaming architecture Roaming architecture Reference points Warning System architecture High level functions General Network access control functions General Network/Access network selection Authentication and authorisation function Admission control function Policy and Charging Enforcement Function Lawful Interception Packet routing and transfer functions General IP header compression function Packet screening function IP Multicast Forwarding between a network accessed by LIPA and a UE Security functions Mobility management functions General Reachability Management for UE in ECM-IDLE state Tracking Area list management Inter-eNodeB mobility anchor function Inter- mobility anchor function Idle mode signalling reduction function Mobility Restrictions IMS voice over PS Session Supported Indication Voice domain preference and UE's usage setting Radio Resource Management functions Network management functions General Load balancing between MMEs Load re-balancing between MMEs MME control of overload General a Throttling of Downlink Data Notification Requests NAS level congestion control PDN GW control of overload Selection functions PDN GW selection function ( accesses) Serving GW selection function MME selection function SGSN selection function Selection of PCRF IP network related functions... 35

4 4 TS V ( ) Domain Name Service function DHCP function Explicit Congestion Notification Functionality for Connection of enodebs to Multiple MMEs E-UTRAN Sharing Function IMS Emergency Session Support Introduction Architecture Reference Model for Emergency Services Mobility and Access Restrictions for Emergency Services a Reachability Management for UE in ECM-IDLE state PDN GW selection function ( accesses) for Emergency Services QoS for Emergency Services PCC for Emergency Services Load re-balancing between MMEs for Emergency Services IP Address Allocation Handling of PDN Connections for Emergency Bearer Services ISR function for Emergency Bearer Services Closed Subscriber Group functions Location Service functions Selected IP Traffic Offload (SIPTO) function Local IP Access (LIPA) function Support for Machine Type Communications (MTC) General Overview of protection from Potential MTC Related Overload Optimizing periodic TAU Signalling UE configuration and usage of indicators Void Multimedia Priority Service General IMS-based Multimedia Priority Services Originating IMS-based MPS Session Terminating IMS-based MPS Session Priority EPS Bearer Services CS fallback Core Network node resolution General MSB in LAC and MME Group ID Explicit Indication Relaying function General RN startup and attach procedure General Attach for RN preconfiguration Attach for RN operation DeNB E-RAB activation/modification Network elements E-UTRAN MME Gateway General Serving GW PDN GW SGSN GERAN UTRAN PCRF General Home PCRF (H-PCRF) Visited PCRF (V-PCRF) PDN GW's associated AAA Server HeNB subsystem DeNB... 54

5 5 TS V ( ) 4.5 Void EPS Mobility Management and Connection Management states General Definition of main EPS Mobility Management states EMM-DEREGISTERED EMM-REGISTERED Definition of EPS Connection Management states ECM-IDLE ECM-CONNECTED State transition and functions Overall QoS concept PDN connectivity service The EPS bearer The EPS bearer in general The EPS bearer with GTP-based S5/S The EPS bearer with PMIP-based S5/S Bearer level QoS parameters Support for Application / Service Layer Rate Adaptation Application of PCC in the Evolved Packet System Compatibility Issues Network Configuration for Interaction with UTRAN/GERAN Functional description and information flows Control and user planes General Control Plane General enodeb - MME UE - MME SGSN - MME SGSN - S-GW S-GW - P-GW MME - MME MME - S-GW MME - HSS MME - EIR CBC - enodeb User Plane UE - P-GW user plane with E-UTRAN enodeb - S-GW UE - PDN GW user plane with 2G access via the S4 interface UE - PDN GW user plane with 3G access via the S12 interface UE - PDN GW user plane with 3G access via the S4 interface Identities EPS bearer identity Globally Unique Temporary UE Identity Tracking Area Identity (TAI) enodeb S1-AP UE Identity (enodeb S1-AP UE ID) MME S1-AP UE Identity (MME S1-AP UE ID) Closed Subscriber Group ID Authentication, security and location management IP address allocation General IP address allocation, renewal and release mechanisms for GTP based S5/S IPv4 address allocation via default bearer activation and release via PDN connection release Allocation, renewal and release of the IPv6 default prefix via IPv6 stateless address autoconfiguration IPv6 parameter configuration via stateless DHCPv IPv4 address allocation, renewal and release and IPv4 parameter configuration via DHCPv Void IPv6 Prefix Delegation via DHCPv Attach procedure... 80

6 6 TS V ( ) E-UTRAN Initial Attach UTRAN/GERAN Initial Attach Tracking Area Update procedures Triggers for tracking area update A Provision of UE's TAI to MME in ECM-CONNECTED state Tracking Area Update procedure with Serving GW change E-UTRAN Tracking Area Update without S-GW Change Routing Area Update with MME interaction and without S-GW change Void Void Routing Area Update with MME interaction and with S-GW change Service Request procedures UE triggered Service Request Handling of abnormal conditions in UE triggered Service Request Network Triggered Service Request S1 release procedure Void GUTI Reallocation procedure Detach procedure General UE-initiated Detach procedure UE-initiated Detach procedure for E-UTRAN UE-initiated Detach procedure for GERAN/UTRAN with ISR activated MME-initiated Detach procedure A SGSN-initiated Detach procedure with ISR activated HSS-initiated Detach procedure HSS User Profile management function procedure General Insert Subscriber Data procedure Purge function Security Function General Authentication and Key Agreement User Identity Confidentiality User Data and Signalling Confidentiality AS security mode command procedure NAS Security Mode Command procedure ME identity check procedure UE Reachability procedures General UE Reachability Notification Request procedure UE Activity Notification procedure Session Management, QoS and interaction with PCC functionality Dedicated bearer activation Bearer modification with bearer QoS update PDN GW initiated bearer modification with bearer QoS update HSS Initiated Subscribed QoS Modification PDN GW initiated bearer modification without bearer QoS update Bearer deactivation PDN GW initiated bearer deactivation MME Initiated Dedicated Bearer Deactivation UE requested bearer resource modification Void Handover Intra-E-UTRAN handover X2-based handover General X2-based handover without Serving GW relocation X2-based handover with Serving GW relocation S1-based handover General S1-based handover, normal

7 7 TS V ( ) S1-based handover, Reject S1-based handover, Cancel Inter RAT handover General E-UTRAN to UTRAN Iu mode Inter RAT handover General Preparation phase Execution phase E-UTRAN to UTRAN Iu mode Inter RAT handover Reject UTRAN Iu mode to E-UTRAN Inter RAT handover General Preparation phase Execution phase UTRAN Iu mode to E-UTRAN Inter RAT handover reject E-UTRAN to GERAN A/Gb mode Inter RAT handover General Preparation phase Execution phase E-UTRAN to GERAN A/Gb mode Inter RAT handover reject GERAN A/Gb mode to E-UTRAN Inter RAT handover General Preparation phase Execution phase GERAN A/Gb mode to E-UTRAN Inter RAT handover reject Inter RAT handover Cancel General Source RAN to Target RAN Inter RAT handover Cancel Network Assisted Cell Change Architecture Principles for E-UTRAN to GERAN NACC Void Information storage HSS MME Serving GW PDN GW UE Handling of Wild Card APN A Charging MBMS Interactions with other services Location Reporting Procedure Location Change Reporting Procedure Multiple-PDN support General UE requested PDN connectivity UE or MME requested PDN disconnection UE Capability Handling General UE Radio Capability Handling UE Core Network Capability Warning message delivery General Warning message delivery procedure Warning message cancel procedure Discontinuous Reception and UE Specific DRX Parameter handling Configuration Transfer procedure Architecture Principles for Configuration Transfer Addressing, routing and relaying Addressing Routing Relaying Applications using the Configuration Transfer procedures

8 8 TS V ( ) 5.15 RAN Information Management (RIM) procedures General Addressing, routing and relaying Addressing Routing Relaying Applications using the RIM Procedures MME-initiated procedure on UE's CSG membership change Home enodeb Multicast Packet Forwarding Function Annex A: Void Annex B: Void Annex C: Void Annex D (normative): Interoperation with Gn/Gp SGSNs D.1 General Considerations D.2 Interoperation Scenario D.2.1 Roaming interoperation scenario D.2.2 Non-roaming interoperation scenario D.3 Interoperation procedures D.3.1 General D.3.2 Void D.3.3 MME to 3G SGSN combined hard handover and SRNS relocation procedure D.3.4 3G SGSN to MME combined hard handover and SRNS relocation procedure D.3.5 Routing Area Update D.3.6 Gn/Gp SGSN to MME Tracking Area Update D.3.7 E-UTRAN to GERAN A/Gb mode Inter RAT handover D General D Preparation phase D Execution phase D.3.8 GERAN A/Gb mode to E-UTRAN Inter RAT handover D General D Preparation phase D Execution phase

9 9 TS V ( ) Annex E (normative): Mapping between EPS and Release 99 QoS parameters Annex F (normative): Dedicated bearer activation in combination with the default bearer activation at Attach and UE requested PDN connectivity procedures Annex G: Void Annex H (normative): Mapping between temporary and area identities Annex I (informative): Guidance for contributors to this specification Annex J (informative): High Level ISR description J.1 General description of the ISR concept J.2 Usage of the TIN J.3 ISR activation J.4 Downlink data transfer J.5 ISR deactivation J.6 Handling of special situations Annex K (informative): Change history

10 10 TS V ( ) Foreword This Technical Specification has been produced by the 3rd Generation Partnership Project (). The contents of the present document are subject to continuing work within the TSG and may change following formal TSG approval. Should the TSG modify the contents of the present document, it will be re-released by the TSG with an identifying change of release date and an increase in version number as follows: Version x.y.z where: x the first digit: 1 presented to TSG for information; 2 presented to TSG for approval; 3 or greater indicates TSG approved document under change control. y the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections, updates, etc. z the third digit is incremented when editorial only changes have been incorporated in the document.

11 11 TS V ( ) 1 Scope The present document defines the Stage 2 service description for the Evolved Packet Switched Domain - also known as the Evolved Packet System (EPS) in this document. The Evolved Packet Switched Domain provides IP connectivity using the Evolved Universal Terrestrial Radio Access Network (E-UTRAN). The specification covers both roaming and non-roaming scenarios and covers all aspects, including mobility between E- UTRAN and pre-e-utran radio access technologies, policy control and charging, and authentication. The Radio Access Network functionality is documented only to the extent necessary to describe the overall system. TS [5] contains the overall description of the Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN). ITU-T Recommendation I.130 [3] describes a three-stage method for characterisation of telecommunication services, and ITU-T Recommendation Q.65 [4] defines Stage 2 of the method. TS [2] is a companion specification to this specification. 2 References The following documents contain provisions which, through reference in this text, constitute provisions of the present document. References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific. For a specific reference, subsequent revisions do not apply. For a non-specific reference, the latest version applies. In the case of a reference to a document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document. [1] TR : "Vocabulary for Specifications". [2] TS : "Architecture enhancements for non- accesses". [3] ITU-T Recommendation I.130: "Method for the characterization of telecommunication services supported by an ISDN and network capabilities of an ISDN". [4] ITU-T Recommendation Q.65: "The unified functional methodology for the characterization of services and network capabilities". [5] TS : "Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access (E-UTRAN); Overall description; Stage 2". [6] TS : "Policy and charging control architecture". [7] TS : "General Packet Radio Service (GPRS); Service description; Stage 2". [8] TS : "Packet-switched handover for GERAN A/Gb mode; Stage 2". [9] TS : "Numbering, addressing and identification". [10] TS : "Non-Access-Stratum (NAS) functions related to Mobile Station in idle mode". [11] TS : "Functions related to MS in idle mode and group receive mode". [12] TS : "UE procedures in idle mode and procedures for cell re-selection in connected mode". [13] TS : "Multimedia Broadcast/Multicast Service (MBMS); Architecture and functional description".

12 12 TS V ( ) [14] TS : "GPRS Tunnelling Protocol (GTP) across the Gn and Gp interface". [15] TS : "GERAN Overall description - Stage 2". [16] TS : "UTRAN overall description". [17] IETF RFC 1034 (1987): "Domain names concepts and facilities" (STD 13). [18] IETF RFC 4862: "IPv6 Stateless Address Autoconfiguration". [19] IETF RFC 2131: "Dynamic Host Configuration Protocol". [20] IETF RFC 3736: "Stateless Dynamic Host Configuration Protocol (DHCP) Service for IPv6". [21] IETF RFC 3633: "IPv6 Prefix Options for Dynamic Host Configuration Protocol (DHCP) version 6". [22] TS : "UTRAN Iu interface Radio Access Network Application Part (RANAP) signalling". [23] TS : "Mobile Station - Serving GPRS Support Node (MS-SGSN); Logical Link Control (LLC) Layer Specification". [24] TS : "Network Sharing; Architecture and functional description". [25] IETF RFC 4039: "Rapid Commit Option for the Dynamic Host Configuration Protocol version 4 (DHCPv4)". [26] IETF RFC 768: "User Datagram Protocol". [27] TS : "Architectural requirements". [28] TS : "Organization of subscriber data". [29] TS : "Customized Applications for Mobile network Enhanced Logic (CAMEL) Phase X; Stage 2". [30] TS : "Intra-domain connection of Radio Access Network (RAN) nodes to multiple Core Network (CN) nodes". [31] IETF RFC 3588: "Diameter Base Protocol". [32] IETF RFC 4861: "Neighbor Discovery for IP Version 6 (IPv6)". [33] TS : "Radio Resource Control (RRC); Protocol Specification". [34] TS : "Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) procedures in idle mode". [35] IETF RFC 4960: "Stream Control Transmission Protocol". [36] TS : "Evolved Universal Terrestrial Access Network (E-UTRAN); S1 Application Protocol (S1AP)". [37] TS : "Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification". [38] TS : "Interworking between the Public Land Mobile Network (PLMN) supporting packet based services and Packet Data Networks (PDN)". [39] Void. [40] TS : "3G Security; Security architecture". [41] TS : " System Architecture Evolution: Security Architecture". [42] TS : "General Packet Radio Service (GPRS); Base Station System (BSS) - Serving GPRS Support Node (SGSN); BSS GPRS Protocol (BSSGP)".

13 13 TS V ( ) [43] TS : " Evolved Packet System (EPS); Evolved General Packet Radio Service (GPRS) Tunnelling Protocol for Control plane (GTPv2-C); Stage 3". [44] TS : "Telecommunication management; Charging management; Packet Switched (PS) domain charging". [45] TS : "Mobile radio interface signalling layer 3; General aspects". [46] TS : "Non-Access-Stratum (NAS) protocol for Evolved Packet System (EPS); Stage 3". [47] TS : "Mobile Radio Interface Layer 3 specification; Core Network Protocols; Stage 3". [48] TS : "Technical realization of Cell Broadcast Service (CBS)". [49] TS : "Network Identity and Time Zone (NITZ) service description; Stage 1". [50] Void. [51] TS : "Charging architecture and principles". [52] TS : "IP Multimedia Subsystem (IMS); Stage 2". [53] TS : "Allowed Closed Subscriber Group (CSG) List; Management Object (MO)". [54] TS : "Alphabets and language-specific information". [55] IETF RFC 3168: "The Addition of Explicit Congestion Notification (ECN) to IP". [56] TS : "IP Multimedia Subsystem (IMS); Multimedia Telephony; Media handling and interaction". [57] TS : "Functional stage 2 description of LCS". [58] TS : "Circuit Switched (CS) fallback in Evolved Packet System (EPS); Stage 2". [59] TS : "Quality of Service (QoS) concept and architecture". [60] TS : "IP Multimedia Subsystem (IMS) centralized services; Stage 2". [61] TS : "Domain Name System Procedures; Stage 3". [62] IETF RFC 3376: "Internet Group Management Protocol, Version 3". [63] IETF RFC 3810: "Multicast Listener Discovery Version 2 (MLDv2) for IPv6". [64] IETF RFC 3927: "Dynamic Configuration of IPv4 Link-Local Addresses". [65] IETF RFC 4291: "IP Version 6 Addressing Architecture". [66] TS : "Service Requirements for Machine-Type Communications (MTC); Stage 1". [67] TS : "Service Accessibility". [68] TS : "Multimedia priority service". [69] TS : "Non-Access Stratum (NAS) configuration Management Object (MO)". [70] IETF Internet-Draft draft-ietf-dhc-pd-exclude-00:"prefix Exclude Option for DHCPv6-based Prefix Delegation". Editor's Note: The above document cannot be formally referenced until it is published as an RFC.

14 14 TS V ( ) 3 Definitions and abbreviations 3.1 Definitions For the purposes of the present document, the terms and definitions given in TR [1] and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR [1]. MME Pool Area: An MME Pool Area is defined as an area within which a UE may be served without need to change the serving MME. An MME Pool Area is served by one or more MMEs ("pool of MMEs") in parallel. MME Pool Areas are a collection of complete Tracking Areas. MME Pool Areas may overlap each other. Serving GW Service Area: A Serving GW Service Area is defined as an area within which a UE may be served without need to change the Serving GW. A Serving GW Service Area is served by one or more Serving GWs in parallel. Serving GW Service Areas are a collection of complete Tracking Areas. Serving GW Service Areas may overlap each other. PDN Connection: The association between a UE represented by one IPv4 address and/or one IPv6 prefix and a PDN represented by an APN. Default Bearer: The EPS bearer which is first established for a new PDN connection and remains established throughout the lifetime of the PDN connection. Default APN: A Default APN is defined as the APN which is marked as default in the subscription data and used during the Attach procedure and the UE requested PDN connectivity procedure when no APN is provided by the UE. Emergency attached UE: A UE which only has bearer(s) related to emergency bearer service. NOTE: The above term is equivalent to the term "attached for emergency bearer services" as specified in TS [46]. LIPA PDN connection: a PDN Connection for local IP access for a UE connected to a HeNB. Correlation ID: For a LIPA PDN connection, Correlation ID is a parameter that enables direct user plane path between the HeNB and L-GW. 3.2 Abbreviations For the purposes of the present document, the abbreviations given in TR [1] and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR [1]. AF ARP AMBR CBC CBE CSG CSG ID DeNB DL TFT ECGI ECM ECN EMM enb EPC EPS E-RAB E-UTRAN GBR GUMMEI Application Function Allocation and Retention Priority Aggregate Maximum Bit Rate Cell Broadcast Centre Cell Broadcast Entity Closed Subscriber Group Closed Subscriber Group Identity Donor enode B DownLink Traffic Flow Template E-UTRAN Cell Global Identifier EPS Connection Management Explicit Congestion Notification EPS Mobility Management evolved Node B Evolved Packet Core Evolved Packet System E-UTRAN Radio Access Bearer Evolved Universal Terrestrial Radio Access Network Guaranteed Bit Rate Globally Unique MME Identifier

15 15 TS V ( ) GUTI GW HeNB HeNB GW HFN ISR OFCS LBI L-GW LIPA MBR MME MMEC MTC M-TMSI OMC-ID P-GW PDCP PMIP PSAP PTI QCI RFSP RN S-GW S-TMSI SDF SIPTO TAC TAD TAI TAU TI TIN URRP-MME UL TFT ULR-Flags Globally Unique Temporary Identity Gateway Home enode B Home enode B Gateway Hyper Frame Number Idle mode Signalling Reduction Offline Charging System Linked EPS Bearer Id Local GateWay Local IP Access Maximum Bit Rate Mobility Management Entity MME Code Machine-Type Communications M-Temporary Mobile Subscriber Identity Operation and Maintenance Centre Identity PDN Gateway Packet Data Convergence Protocol Proxy Mobile IP Public Safety Answering Point Procedure Transaction Id QoS Class Identifier RAT/Frequency Selection Priority Relay Node Serving Gateway S-Temporary Mobile Subscriber Identity Service Data Flow Selected IP Traffic Offload Tracking Area Code Traffic Aggregate Description Tracking Area Identity Tracking Area Update Transaction Identifier Temporary Identity used in Next update UE Reachability Request Parameter for MME UpLink Traffic Flow Template Update Location Request Flags

16 16 TS V ( ) 4 Architecture model and concepts 4.1 General concepts Local breakout of IP traffic via the visited PLMN is supported, when network policies and user subscription allow it. Local breakout may be combined with support for multiple simultaneous PDN connections, described in clause Architecture reference model Non-roaming architecture UTRAN SGSN GERAN S3 S1-MME MME S11 LTE-Uu S10 UE E-UTRAN S1-U HSS S6a S4 Serving Gateway S12 S5 Gx PDN Gateway PCRF SGi Rx Operator's IP Services (e.g. IMS, PSS etc.) Figure : Non-roaming architecture for accesses UTRAN SGSN GERAN S3 S1-MME MME S11 LTE-Uu S10 UE E-UTRAN S1-U HSS S6a S4 Serving Gateway S12 Gx PDN Gateway PCRF SGi Rx Operator's IP Services (e.g. IMS, PSS etc.) Figure : Non-roaming architecture for accesses. Single gateway configuration option NOTE 1: Also in this configuration option, S5 can be used between non collocated Serving Gateway and PDN Gateway. NOTE 2: Additional interfaces for 2G/3G access are shown in TS [7].

17 17 TS V ( ) Roaming architecture HSS PCRF Gx Rx S6a PDN Gateway SGi Operator s IP Services (e.g. IMS, PSS etc.) HPLMN VPLMN UTRAN S8 SGSN GERAN S1 - MME S3 MME S4 S12 S11 UE LTE - Uu E - UTRAN S10 S 1 - U Serving Gateway Figure : Roaming architecture for accesses. Home routed traffic NOTE 1: Additional interfaces/reference points for 2G/3G accesses are documented in TS [7]. The figures and represent the Roaming with local breakout case with Application Function (AF) in the Home Network and in the Visited Network respectively. The concurrent use of AF's in the home network and AF's in the visited network is not excluded.

18 18 TS V ( ) HSS H - PCRF Rx S6a HPLMN S9 Home Operator s IP Services VPLMN UTRAN S G SN GERAN S1 - MME S3 MME S4 S12 Gx V - PCRF S11 UE "LTE - Uu" E - UTRAN S10 S1 - U Serving G ateway S 5 PDN G ateway SGi Visited Oper ator PDN Figure : Roaming architecture for local breakout, with home operator's application functions only NOTE 2: See TS [6] for the role of and functions related to Home and Visited PCRF and S9/Rx reference points. NOTE 3: In figure , the control plane signalling and the user plane for accessing to Home Operator's services traverse over the SGi reference point via the Visited Operator's PDN.

19 19 TS V ( ) HSS H-PCRF S6a HPLMN S9 VPLMN UTRAN GERAN SGSN S1-MME S3 MME S4 S12 Gx V-PCRF Rx S11 UE LTE-Uu E-UTRAN S10 S1-U Serving Gateway S5 PDN Gateway SGi Visited Operator's IP Services Figure : Roaming architecture for local breakout, with visited operator's application functions only Reference points S1-MME: Reference point for the control plane protocol between E-UTRAN and MME. S1-U: Reference point between E-UTRAN and Serving GW for the per bearer user plane tunnelling and inter enodeb path switching during handover. S3: It enables user and bearer information exchange for inter access network mobility in idle and/or active state. This reference point can be used intra-plmn or inter-plmn (e.g. in the case of Inter-PLMN HO). S4: It provides related control and mobility support between GPRS Core and the Anchor function of Serving GW. In addition, if Direct Tunnel is not established, it provides the user plane tunnelling. S5: It provides user plane tunnelling and tunnel management between Serving GW and PDN GW. It is used for Serving GW relocation due to UE mobility and if the Serving GW needs to connect to a noncollocated PDN GW for the required PDN connectivity. S6a: Gx: It enables transfer of subscription and authentication data for authenticating/authorizing user access to the evolved system (AAA interface) between MME and HSS. It provides transfer of (QoS) policy and charging rules from PCRF to Policy and Charging Enforcement Function (PCEF) in the PDN GW. S8: Inter-PLMN reference point providing user and control plane between the Serving GW in the VPLMN and the PDN GW in the HPLMN. S8 is the inter PLMN variant of S5. S9: It provides transfer of (QoS) policy and charging control information between the Home PCRF and the Visited PCRF in order to support local breakout function. S10: Reference point between MMEs for MME relocation and MME to MME information transfer. This reference point can be used intra-plmn or inter-plmn (e.g. in the case of Inter-PLMN HO). S11: Reference point between MME and Serving GW.

20 20 TS V ( ) S12: Reference point between UTRAN and Serving GW for user plane tunnelling when Direct Tunnel is established. It is based on the Iu-u/Gn-u reference point using the GTP-U protocol as defined between SGSN and UTRAN or respectively between SGSN and GGSN. Usage of S12 is an operator configuration option. S13: It enables UE identity check procedure between MME and EIR. SGi: It is the reference point between the PDN GW and the packet data network. Packet data network may be an operator external public or private packet data network or an intra operator packet data network, e.g. for provision of IMS services. This reference point corresponds to Gi for accesses. Rx: The Rx reference point resides between the AF and the PCRF in the TS [6]. SBc: Reference point between CBC and MME for warning message delivery and control functions. When data forwarding is used as part of mobility procedures different user plane routes may be used based on the network configuration (e.g. direct or indirect data forwarding). These routes can be between enodeb and RNC, enodeb and SGSN, RNC and S-GW or between S-GW and SGSN. Explicit reference points are not defined for these routes. These user plane forwarding routes can cross inter-plmn boundaries (e.g. in the case of Inter-PLMN HO). Protocol assumption: - The S1-U is based on GTP-U protocol; - The S3 is based on GTP protocol; - The S4 is based on GTP protocol; - The S5 is based on GTP protocol. PMIP variant of S5 is described in TS [2]; - The S8 is based on GTP protocol. PMIP variant of S8 is described in TS [2]. - S3, S4, S5, S8, S10 and S11 interfaces are designed to manage EPS bearers as defined in clause NOTE: Redundancy support on reference points S5 and S8 should be taken into account Warning System architecture UE E-UTRAN MME CBC CBE LTE-Uu S1-MME SBc Figure : Warning System Architecture for Accesses NOTE: The CBE and the interface between CBE and CBC are out of scope of specifications. 4.3 High level functions General The following list gives the logical functions performed within this system. Several functional groupings (meta functions) are defined and each encompasses a number of individual functions: - Network Access Control Functions. - Packet Routing and Transfer Functions. - Mobility Management Functions. - Security Functions.

21 21 TS V ( ) - Radio Resource Management Functions. - Network Management Functions Network access control functions General Network access is the means by which a user is connected to the evolved packet core system Network/Access network selection It is the means by which a UE selects a PLMN/Access network from which to gain IP connectivity. The network/access network selection procedure varies for different access technologies. For access networks, the network selection principles are described in TS [10]. For access networks, the access network selection procedures are described in TS [5], TS [11] and TS [12]. Architectural impacts stemming from support for network/access network selection procedures for non- access and between access and non- accesses are described in TS [2] Authentication and authorisation function This function performs the identification and authentication of the service requester, and the validation of the service request type to ensure that the user is authorised to use the particular network services. The authentication function is performed in association with the Mobility Management functions Admission control function The purpose of admission control is to determine if the requested resources are available, and then reserve those resources Policy and Charging Enforcement Function This includes all the functionality of PCEF as defined by TS [6]. The PCEF encompasses service data flow detection, policy enforcement and flow based charging functionalities as defined in TS [6] Lawful Interception Lawful interception is the action, performed by a network operator / access provider / service provider, of making available certain information and providing that information to a law enforcement monitoring facility Packet routing and transfer functions General A route is an ordered list of nodes used for the transfer of packets within and between the PLMN(s). Each route consists of the originating node, zero or more relay nodes and the destination node. Routing is the process of determining and using, in accordance with a set of rules, the route for transmission of a message within and between the PLMN(s). The EPS is an IP network and uses the standard routing and transport mechanisms of the underlying IP network. The Maximum Transfer Unit (MTU) size considerations in clause 9.3 of TS [7] are also applicable to EPS IP header compression function The IP header compression function optimises use of radio capacity by IP header compression mechanisms.

22 22 TS V ( ) Packet screening function The packet screening function provides the network with the capability to check that the UE is using the exact IPv4- Address and/or IPv6-Prefix that was assigned to the UE IP Multicast Forwarding between a network accessed by LIPA and a UE The Home enodeb L-GW should support IP forwarding of packets to multicast groups between the UE and the network accessed by LIPA Security functions The security functions are described in clause Mobility management functions General The mobility management functions are used to keep track of the current location of a UE Reachability Management for UE in ECM-IDLE state The location of a UE in ECM-IDLE state is known by the network on a Tracking Area List granularity. A UE in ECM- IDLE state is paged in all cells of the Tracking Areas in which it is currently registered. The UE may be registered in multiple Tracking Areas. All the tracking areas in a Tracking Area List to which a UE is registered are served by the same serving MME. An EMM-REGISTERED UE performs periodic Tracking Area Updates with the network after the expiry of the periodic TAU timer. The MME may allocate long periodic TAU timer value to the UE according to clause If the UE is out of E-UTRAN coverage (including the cases when the UE is camped on GERAN/UTRAN cells) when its periodic TAU timer expires, the UE shall: - if ISR is activated, start the E-UTRAN Deactivate ISR timer. After the E-UTRAN Deactivate ISR timer expires the UE shall deactivate ISR by setting its TIN to "P-TMSI". - if ISR is activated and the UE is camping on a GERAN/UTRAN cell (or returns to coverage in GERAN/UTRAN) and the UE is EPS/IMSI attached, perform a LAU procedure in NMO II/III or a combined RA/LA update procedure in NMO I. - when EMM-REGISTERED, perform a Tracking Area Update when it next returns to E-UTRAN coverage. If the UE is camped on an E-UTRAN cell or is in ECM-CONNECTED state when the UE's periodic RAU timer expires, the UE shall: - if ISR is activated, start the GERAN/UTRAN Deactivate ISR timer. After the GERAN/UTRAN Deactivate ISR timer expires the UE shall deactivate ISR by setting its TIN to "GUTI". - perform a Routing Area Update when it next returns to GERAN/UTRAN coverage. If the UE is EPS attached only and either camps on an E UTRAN cell or is in ECM CONNECTED state when the UE's periodic LAU timer expires, the UE shall perform a Location Area Update procedure in NMO II/III or combined RA/LA update in NMO I when it next returns to GERAN/UTRAN coverage. The E-UTRAN Deactivate ISR timer is stopped when the UE performs a successful Tracking Area Update or combined TA/LA Update; and the GERAN/UTRAN Deactivate ISR timer is stopped when the UE performs a successful Routing Area Update or combined RA/LA Update. Expiry of the periodic TAU timer, or, the periodic RAU timer, or, the periodic LAU timer shall not cause the UE to change RAT.

23 23 TS V ( ) The UE's periodic TAU timer is restarted from its initial value whenever the UE enters ECM-IDLE mode and when the UE leaves the E-UTRAN connection due to handover to GERAN/UTRAN. UTRAN RRC state transitions and GERAN GPRS STANDBY/READY state transitions shall have no other impact on the periodic TAU timer. E-UTRAN RRC state transitions shall have no impact on the periodic RAU timer or periodic LAU timer except that handover from GERAN/UTRAN to E-UTRAN shall cause the periodic RAU timer to be started from its initial value. Handover from E UTRAN to UTRAN/GERAN shall cause the periodic TAU timer to be started from its initial value. Typically, the MME runs a mobile reachable timer with a similar value to the UE's periodic TAU timer. If this timer expires in the MME, the MME can deduce that the UE is 'out of coverage' at that moment. However, the MME does not know for how long the UE has been out of coverage, so, the MME shall not immediately delete the UE's bearers. Instead the MME should clear the PPF flag in the MME and start an Implicit Detach timer, with a relatively large value and if ISR is activated, at least slightly larger than the UE's E-UTRAN Deactivate ISR timer. With the PPF clear, the MME does not page the UE in E-UTRAN coverage and shall send a Downlink Data Notification Reject message to the Serving GW when receiving a Downlink Data Notification message from the Serving GW. If this Implicit Detach timer expires before the UE contacts the network, then the MME can deduce that the UE has been 'out of coverage' for a long period of time and implicitly detach the UE as described in clause "MME-initiated Detach procedure". When the MME applies General NAS level Mobility Management Congestion Control to a UE, the MME may need to adjust the mobile reachable timer and/or Implicit Detach timer (as clause ). NOTE 1: The SGSN has similar functionality as the MME. NOTE 2: Alternative MME implementations are permitted, however, the externally visible MME behaviour should conform to the above description Tracking Area list management Tracking Area list management comprises the functions to allocate and reallocate a Tracking Area Identity list to the UE. All the tracking areas in a Tracking Area List to which a UE is registered are served by the same serving MME. The "tracking area list concept" is used with E-UTRAN. With this concept, when the UE registers with the network, the MME allocates a set (a "list") of tracking areas to the UE. By making the centre of this set of tracking areas close to the UE's current location, the chance of a UE rapidly making another tracking area update can be reduced. NOTE: This TAI list functionality is different to the SGSN behaviour in GERAN and UTRAN systems. In GERAN/UTRAN the UE is only registered in one Routeing Area at a time Inter-eNodeB mobility anchor function The Inter-eNodeB Mobility Anchor is the functional entity that anchors the user plane for E-UTRAN mobility Inter- mobility anchor function The Inter- Mobility Anchor is the functional entity that anchors the user plane for mobility between 2G/3G access systems and the E-UTRA access system Idle mode signalling reduction function The Idle mode Signalling Reduction (ISR) function provides a mechanism to limit signalling during inter-rat cellreselection in idle mode (ECM-IDLE, PMM-IDLE, GPRS STANDBY states). NOTE 1: The Idle mode Signalling Reduction function is mandatory for E-UTRAN UEs that support GERAN and/or UTRAN and optional for core network. The UE's ISR capability in the UE Core Network Capability element is for test purpose. The MME/SGSN activates ISR only if the Serving GW supports the ISR. How MME/SGSN determines a Serving GW supports ISR is implementation dependent. ISR shall be activated by decision of the CN nodes and shall be explicitly signalled to the UE as "ISR activated" in the RAU and TAU Accept messages. The UE may have valid MM parameters both from MME and from SGSN. The "Temporary Identity used in Next update" (TIN) is a parameter of the UE's MM context, which identifies the UE

24 24 TS V ( ) identity that the UE shall indicate in the next RAU Request, TAU Request or Attach Request message. The TIN also identifies the status of ISR activation in the UE. The TIN can take one of the three values, "P-TMSI", "GUTI" or "RAT-related TMSI". The UE shall set the TIN when receiving an Attach Accept, a TAU Accept or RAU Accept message according to the rules in table Table : Setting of the TIN Message received by UE Attach Accept via E-UTRAN (never indicates "ISR Activated") Attach Accept via GERAN/UTRAN (never indicates "ISR Activated") TAU Accept not indicating "ISR Activated" TAU Accept indicating "ISR Activated" RAU Accept not indicating "ISR Activated" RAU Accept indicating "ISR Activated" Current TIN value stored by UE Any value Any value Any value GUTI P-TMSI or RAT-related TMSI Any value P-TMSI GUTI or RAT-related TMSI TIN value to be set by the UE when receiving message GUTI P-TMSI GUTI GUTI RAT-related TMSI P-TMSI P-TMSI RAT-related TMSI When "ISR Activated" is indicated by the RAU/TAU Accept message but the UE shall not set the TIN to "RAT-related TMSI" is a special situation. Here the UE has deactivated ISR due to special situation handling. By maintaining the old TIN value the UE remembers to use the RAT specific TMSI indicated by the TIN when updating with the CN node of the other RAT. Only if the TIN is set to "RAT-related TMSI" ISR behaviour is enabled for the UE, i.e. the UE can change between all registered areas and RATs without any update signalling and it listens for paging on the RAT it is camped on. If the TIN is set to "RAT-related TMSI", the UE's P-TMSI and RAI as well as its GUTI and TAI(s) shall remain registered with the network and shall remain valid in the UE. Table : Temporary UE Identity that the UE shall indicate in Attach Request and TAU/RAU Request (as "old GUTI" or as "old P-TMSI/RAI" information element) Message to be sent by UE TIN value: P-TMSI TIN value: GUTI TIN value: RAT-related TMSI TAU Request GUTI mapped from GUTI GUTI P-TMSI/RAI RAU Request P-TMSI/RAI P-TMSI/RAI mapped from P-TMSI/RAI GUTI Attach Request via E- GUTI mapped from GUTI GUTI UTRAN P-TMSI/RAI Attach Request via GERAN/UTRAN P-TMSI/RAI P-TMSI/RAI mapped from GUTI P-TMSI/RAI Table shows which temporary identity the UE shall indicate in a Tracking or Routing Area Update Request or in an Attach Request message, when the UE stores these as valid parameters. Situations may occur that cause unsynchronized state information in the UE, MME and SGSN. Such special situations trigger a deactivation of ISR locally in the UE. The UE shall deactivate ISR locally by setting its TIN to the temporary identity of the currently used RAT in following special situations: - Modification of any EPS bearer context or PDP context which was activated before the ISR is activated in the UE; - At the time when the UE moves from E-UTRAN to GERAN/UTRAN or moves from GERAN/UTRAN to E-UTRAN by means other than PSHO, if any EPS bearer context or PDP context activated after the ISR was activated in the UE exists;

25 25 TS V ( ) - After updating either MME or SGSN about the change of the UE specific DRX parameters to guarantee that the other CN node is also updated; - After updating either MME or SGSN about the change of the UE Core Network Capabilities to guarantee that the other CN node is also updated; - E-UTRAN selection by a UTRAN-connected UE (e.g. when in URA_PCH to release Iu on UTRAN side); - After a LAU procedure if the UE has CS fallback and/or SMS over SGs activated. - For a UE that is IMS registered for voice, then after that UE moves from a Registration Area that supports IMS voice over PS sessions (see for more information) to one that does not, and vice versa. It shall be possible, e.g. using Device Management or initial provisoning, to configure the UE to apply/not apply this particular exception. NOTE 2: A UE moving between Registration Areas that both support IMS voice over PS sessions, or, both that do not support IMS voice over PS sessions, is unaffected by the above. The UE shall deactivate ISR locally by setting its TIN to the temporary identity of the RAT that is still available to the UE in following special situations: - After the RAT-specific Deactivate ISR timer expires, e.g. because the coverage of that RAT is lost or the RAT is no more selected by the UE (this may result also in implicit detach by SGSN or MME). ISR shall be deactivated in the UE by the CN node using normal update signalling, i.e. by omitting the signalling of "ISR Activated", in following special situations: - CN node change resulting in context transfer between the same type of CN nodes (SGSN to SGSN or MME to MME); - Serving GW change; - When the UE only has bearers related to emergency bearer service Mobility Restrictions Mobility Restrictions comprises the functions for restrictions to mobility handling of a UE in E-UTRAN access. The Mobility Restriction functionality is provided by the UE, the radio access network and the core network. Mobility Restriction functionality in state ECM-IDLE is executed in UE based on information received from the core network. Mobility Restriction functionality in state ECM-CONNECTED is executed in the radio network and the core network. In state ECM-CONNECTED, the core network provides the radio network with a Handover Restriction List. The Handover Restriction List specifies roaming, area and access restrictions IMS voice over PS Session Supported Indication The serving PLMN shall send an indication toward the UE during the Attach procedure and Tracking Area Update procedures if an IMS voice over PS session is supported. The serving PLMN uses this indicator to indicate to the UE whether it can expect a successful IMS voice over PS session. A UE with "IMS voice over PS" voice capability should take this indication into account when establishing voice over PS sessions (as specified in TS [27]) as well as when determining whether to deactivate the special handling of ISR locally (as detailed in clause ). The serving PLMN provides this indication based e.g. on local policy, HPLMN, the SRVCC capability of the network and UE and/or extends of E-UTRAN/UTRAN coverage. The serving PLMN shall indicate to the UE that the UE can expect a successful IMS voice over PS session only if the MME is configured to know that the serving PLMN has a roaming agreement for IMS voice with the HPLMN of the UE. This indication is per TAI list. On request by the HSS, the MME shall indicate the following: - whether or not an IMS voice over PS Session is supported in the TA(s) that are registered for the UE ("IMS voice over PS Session Supported Indication"), together with the time of the last radio contact with the UE; and - the current RAT type.