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.

For the purposes of the present document, the abbreviations listed in TR 21.905 apply. GEO LEO MEO NCGI NR RG

The term subscriber data is used to designate all information associated with a subscription which is required for service provisions, identification, authentication, routing, call handling, GPRS mode transmission, charging, subscriber tracing, operation and maintenance purposes. Some subscriber data are referred to as permanent subscriber data, i.e. they can only be changed by administration means. Other data are temporary subscriber data which may change as a result of normal operation of the system. Unless shown to be conditional, all data items are considered to be mandatory.

This specification considers subscriber data stored by the following types of network functions:

• Home subscriber server (HSS) which contains all permanent subscriber data and all relevant temporary subscriber data to support the call control and session management entities of the different Domains and Subsystems.
• Home location register (HLR) which contains all permanent subscriber data and all relevant temporary subscriber data for all mobile subscribers permanently registered in the HLR for CS and PS Domains.
• CSG subscriber server (CSS) which contains Closed Subscriber Group information data for inbound roaming UEs to enable VPLMN autonomous CSG roaming in CS and PS domains.
• Visitor location register (VLR) which contains all subscriber data required for call handling and other purposes for mobile subscribers currently located in the area controlled by the VLR.
• Serving GPRS Support Node (SGSN) which contains all subscriber data required for GPRS mode transmission and other purposes for mobile subscribers currently located in the area controlled by the SGSN.
• Gateway GPRS Support Node (GGSN) which contains all subscriber data required for GPRS mode transmission for mobile subscribers using any service provided by the GGSN.
• Mobility Management Entity (MME) which contains all subscriber data required for EPS mode transmission and other purposes for mobile subscribers currently located in the area controlled by the MME.
• Serving GW (S-GW) which contains all subscriber data required for EPS mode transmission for mobile subscribers currently served by the S-GW.
• PDN GW (P-GW) which contains all subscriber data required for EPS mode transmission for mobile subscribers using any service provided by the P-GW.
• ePDG which contains all subscriber data required for EPS mode transmission for mobile subscribers currently served by the ePDG via a non 3GPP access.
• Gateway Mobile Location Center (GMLC) which contains all subscriber data required for external clients of the Location Services (LCS).
• In GSM, Serving Mobile Location Center (SMLC) which contains all LMU data required to manage location measurements in LMUs.
• Serving Call Session Control Function (S-CSCF) which handles the session states in the IP Multimedia (IM) Subsystem. Further definition of the S-CSCF is provided in TS 23.228.
• SUPL (Secure User Plane Location) Location Platform (SLP) provides user location information to the ProSe Function. Further information is provided in TS 23.303.
• ProSe Function is the logical function that is used for network related actions required for Proximity services more details are provided in TS 23.303.
• ProSe Application Server stores EPC ProSe User IDs and ProSe Function IDs and performs the mapping of Application Layer User IDs and EPC ProSe User Ids (see TS 23.303).
• V2X Control Function is the logical function that is used for network related actions required for V2X services more details are provided in TS 23.285.
• UDM, AMF, SMF, SMSF, AUSF and NEF in 5G System (see TS 23.501 and TS 23.502).

In addition, subscriber data may also be stored in the following functional unit:

• Group Call Register (GCR) which contains all data required for configuration, set-up and handling of voice group and voice broadcast calls. This encompasses subscribers identities (mobile as well as fixed network) who are nominated as dispatchers for one or several groups within the area controlled by the GCR.

The individual Subscriber Authentication Key Ki defined in TS 43.020 is stored in the Authentication Centre (AuC); it is also stored in the SIM and therefore available in the MS. Version numbers of algorithms A3 and A8 may also be stored in the AuC. Bootstrapping Server Function (BSF) handles subscriber's bootstrapping information after bootstrapping procedure in Generic Authentication Architecture (GAA) system. A bootstrapping procedure creates security association between an UE and a BSF. Using the stored user's bootstrapping information and the security association the BSF can provide security services to network application functions (NAF) contacted by the UE. Functions of the BSF are defined in TS 33.220 and TS 29.109.

This specification considers subscriber data stored in the following types of functional unit for I-WLAN:

• 3GPP AAA Server which contains all subscriber data necessary to maintain WLAN Direct IP Access and WLAN 3GPP IP Access.
• 3GPP AAA Proxy which contains subscriber data necessary to perform AAA proxy functionality in the VPLMN and to provide charging inter operator settlement functionality.
• Packet Data Gateway (PDG) which contains all subscriber data necessary to manage WLAN 3GPP IP Access tunnels.
• WLAN Access Gateway (WAG) which contains all subscriber data necessary to manage a per user firewall between the WLAN-AN and PLMN and to perform per tunnel charging.