1 Scope

23.0073GPPRelease 18Restoration proceduresTS

The data stored in location registers are automatically updated in normal operation; the main information stored in a location register defines the location of each mobile station and the subscriber data required to handle traffic for each mobile subscriber. The loss or corruption of these data will seriously degrade the service offered to mobile subscribers; it is therefore necessary to define procedures to limit the effects of failure of a location register, and to restore the location register data automatically. The present document defines the necessary procedures.

The basic principle is that restoration should be based on radio contact to avoid faulty data being spread in the system.

Subscriber data for supplementary services must also be correctly restored, although the impact on service of corruption of supplementary service data is less severe.

Procedures for supporting these functions are defined in 3GPP TS 29.002 [6] and 3GPP TS 29.060 [8].

The MAP operation "IMSI Attach" is used only in MAP version 1; in MAP version 2 the same function is performed by the MAP operation "Update Location Area". References in this specification to IMSI attach apply only to MAP version 1 network entities.

If the restoration of subscriber data in the VLR is triggered by Location Updating or IMSI Attach, the VLR retrieves subscriber data from the HLR by sending an "Update Location" request, which triggers one or more "Insert Subscriber Data" operations from the HLR. The "Update Location" request may also be used to send the LMSI to the HLR.

If the restoration of subscriber data in the VLR is triggered by a "Provide Roaming Number" request, the behaviour of the VLR depends on whether it is implemented according to MAP version 1 or MAP version 2. For MAP version 2, the VLR retrieves subscriber data from the HLR by sending a "Restore Data" request, which triggers one or more "Insert Subscriber Data" operations from the HLR. The "Restore Data" request is also used to send the LMSI to the HLR. For MAP version 1, the VLR retrieves subscriber data from the HLR by sending a "Send Parameters" request with parameter type "Subscriber Data", which cannot be used to send the LMSI to the HLR.

The VLR number and MSC number in the subscriber data in the HLR are updated by the "Update Location" procedure.

The GGSN (Gateway GPRS Support Node) is the point of PDN interconnection with the GSM PLMN supporting GPRS. The GGSN contains routing information for GPRS users with a PDP context active. The necessary procedures needed to restore GGSN data information after a restart are described in this document.

The SGSN (Serving GPRS Support Node) is the node that is serving the MS. The SGSN stores information regarding e.g. mobility management, routing and security. The necessary procedures needed to restore this SGSN information after a restart are described in this document.

The MME (Mobility Management Entity) is the node that is serving the UE when attached to E-UTRAN. The MME stores information regarding e.g. mobility management, routing and security. The necessary procedures needed to restore this MME information after a restart are described in this document.

A Type A LMU (Location Measurement Unit) is a network node, accessed over the GSM air interface, that is functionally similar to an MS. All requirements associated with a non-GPRS MS in this specification apply also to a Type A LMU except where specified otherwise.

1.1 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 3GPP 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] 3GPP TR 21.905: "Vocabulary of 3GPP Specifications ".

[2] Void

[3] Void

[4] 3GPP TS 23.040: "Technical realization of the Short Message Service (SMS)".

[5] 3GPP TS 23.060: "General Packet Radio Service (GPRS); Service description; Stage 2".

[6] 3GPP TS 29.002: "Mobile Application Part (MAP) specification".

[7] 3GPP TS 29.018: "General Packet Radio Service (GPRS); Serving GPRS Support Node (SGSN) – Visitors Location Register (VLR); Gs interface layer 3 specification".

[8] 3GPP TS 29.060: "General Packet Radio Service (GPRS); GPRS Tunneling Protocol (GTP) across the Gn and Gp interface".

[9] 3GPP TS 43.005: "Technical performance objectives".

[10] 3GPP TS 23.071: " Location Services (LCS); Functional description; Stage 2".

[11] Void

[12] 3GPP TS 23.246: "Multimedia Broadcast/Multicast Service (MBMS); Architecture and functional description".

[13] 3GPP TS 29.274: "3GPP Evolved Packet System (EPS); Evolved General Packet Radio Service (GPRS) Tunnelling Protocol for Control plane (GTPv2-C); Stage 3".

[14] 3GPP TS 29.118:"Mobility Management Entity (MME) – Visitor Location Register (VLR) SGs interface specification".

[15] 3GPP TS 23.401: "General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access".

[16] 3GPP TS 29.275: "Proxy Mobile IPv6 (PMIPv6) based Mobility and Tunneling protocols; Stage 3".

[17] 3GPP TS 29.281: "General Packet Radio System (GPRS) Tunneling Protocol User Plane (GTPv1-U)".

[18] 3GPP TS 23.402: "Architecture enhancements for non-3GPP accesses".

[19] 3GPP TS 24.301: "Non-Access-Stratum (NAS) protocol for Evolved Packet System (EPS); Stage 3".

[20] 3GPP TS 24.008: "Mobile radio interface Layer 3 specification; Core network protocols; Stage 3".

[21] 3GPP TS 29.213: "Policy and charging control signalling flows and Quality of Service (QoS) parameter mapping ".

[22] IETF RFC 5847: "Heartbeat Mechanism for Proxy Mobile IPv6".

[23] 3GPP TS 23.018: "Basic call handling; Technical realization".

[24] 3GPP TS 23.236: "Intra-domain connection of Radio Access Network (RAN) nodes to multiple Core Network (CN) nodes".

[25] 3GPP TS 29.212: "Policy and Charging Control (PCC); Reference points".

[26] IETF RFC 7077: "Update Notifications for Proxy Mobile IPv6".

[27] 3GPP TS 23.122: "Non-Access-Stratum (NAS) functions related to Mobile Station (MS) in idle mode".

[28] 3GPP TS 36.444: "EUTRAN M3 Application Protocol (M3AP)".

[29] 3GPP TS 25.413: "UTRAN Iu interface RANAP signalling".

[30] 3GPP TS 23.041: "Technical realization of Cell Broadcast Service (CBS)".

[31] 3GPP TS 29.061: "Interworking between the Public Land Mobile Network (PLMN) supporting packet based services and Packet Data Networks (PDN) ".

[32] 3GPP TS 36.300: "Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2".

[33] 3GPP TS 23.303: "Proximity based Services; Stage 2".

[34] 3GPP TS 29.344: "Proximity-services (ProSe) Function to Home Subscriber Server (HSS) aspects; Stage 3".

[35] 3GPP TS 29.468: "Group Communication System Enablers for LTE (GCSE_LTE); MB2 Reference Point; Stage 3".

[36] 3GPP TS 29.468: "Group Communication System Enablers for LTE (GCSE_LTE); MB2 Reference Point; Stage 3".

[37] 3GPP TS 29.303: "Domain Name System Procedures; Stage 3".

[38] 3GPP TS 23.682: "Architecture enhancements to facilitate communications with packet data networks and applications".

[39] 3GPP TS 23.161: "Network-Based IP Flow Mobility (NBIFOM); Stage 2".

[40] 3GPP TS 23.285: "Architecture enhancements for V2X services; Stage 2".

[41] 3GPP TS 29.388: "V2X Control Function to V2X Control Function to Home Subscriber Server (HSS) aspects (V4)". .

[42] 3GPP TS 23.214: "Architecture enhancements for control and user plane separation of EPC nodes; Stage 2".

[43] 3GPP TS 29.244: "Interface between the Control Plane and the User Plane of EPC Nodes; stage 3".

[44] 3GPP TS 29.674:" Interface between the UCMF and the MME; Stage 3".

[45] 3GPP TS 23.501: "System Architecture for the 5G System; Stage 2".

[46] 3GPP TS 23.502: "Procedures for the 5G System; Stage 2".

[47] 3GPP TS 23.632: "User data interworking, coexistence and migration; Stage 2".

1.2 Abbreviations

For the purposes of the present document, the abbreviations listed in 3GPP TR 21. 905 [1] apply.

1.3 Definitions

For the purposes of the present document, the terms and definitions given in TR 21.905 [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 21.905 [1].

PDN Connection: "PDN Connection" in this specification only refers to the PDN connection through the SGW and PGW.

SCEF PDN Connection: The PDN connection to the SCEF. Unless otherwise indicated in a clause or clause, "PDN Connections" do not refer to any SCEF PDN Connection.