Content for  TS 23.280  Word version:  18.6.0

The reference points for the application plane of an MC service are described in the following subclauses.

The CSC-1 reference point, which exists between the identity management client and the identity management server, provides for the authentication of the common services core to the MC service client and subsequent authentication of the user to the common services core on behalf of applications within the application plane. CSC-1 is specified in TS 33.180.

The CSC-2 reference point, which exists between the group management client and the group management server, is used for MC service signalling for MC service data management of the MC service. The CSC-2 reference point supports:

• Configuration of group related data at the group management client by the group management server; and
• Configuration of group related data at the group management server by the group management client.

The CSC-2 reference point shall use the HTTP-1 and HTTP-2 reference points for transport and routing of non-subscription/notification related signalling. The CSC-2 reference point shall use SIP-1 and SIP-2 reference points for transport and routing of subscription/notification related signalling.

The CSC-3 reference point, which exists between the MC service server and the group management server, provides for the MC service server to obtain group information corresponding to the MC service. The CSC-3 reference point shall use HTTP-1 and HTTP-2 reference points for transport and routing of non-subscription/notification related signalling. The CSC-3 reference point shall use SIP-2 and SIP-3 reference points for transport and routing of subscription/notification related signalling. The SIP-3 reference point is used when a MC service server and the group management server, are served by different SIP cores.

The CSC-4 reference point, which exists between the configuration management client and the configuration management server, provides the configuration information required for MC services while the MC service client is on-network. The CSC-4 reference point supports:

• configuration of the MC service UE by the MC service; and
• configuration of the MC service application with the MC service related information that is not part of group management (e.g. policy information) by the MC service UE.

The CSC-4 reference point shall use the HTTP-1 and HTTP-2 reference points for transport and routing of non-subscription/notification related signalling. The CSC-4 reference point shall use SIP-1 and SIP-2 reference points for transport and routing of subscription/notification related signalling.

The CSC-5 reference point, which exists between the MC service server and the configuration management server, provides for the MC service server to obtain non-group MC service related information (e.g. policy information). The CSC-5 reference point shall use HTTP-1 reference point and HTTP-2 reference point for transport and routing of non-subscription/notification related signalling. The CSC-5 reference point shall use SIP-2 and SIP-3 reference points for transport and routing of subscription/notification related signalling. The SIP-3 reference point is used when a MC service server and the configuration management server, are served by different SIP cores.

The CSC-7 reference point, which exists between group management servers, allows group management servers to handle group management related signalling in the same security domain. The CSC-7 reference point shall use the HTTP-1, HTTP-2 and HTTP-3 reference points for transport and routing of non-subscription/notification related signalling. The CSC-7 reference point shall use SIP-2 and SIP-3 reference points for transport and routing of subscription/notification related signalling. The SIP-3 reference point is used when a pair of group management servers, are served by different SIP cores.

The CSC-8 reference point, which exists between the key management server and the key management client, provides a means for the key management server to provide security related information (e.g. encryption keys) to the key management client. The CSC-8 reference point shall use the HTTP-1 and HTTP-2 reference points for transport and routing of security related information to the key management client. CSC-8 is specified in TS 33.180.

The CSC-9 reference point, which exists between the key management server and the MC service server, provides a means for the key management server to provide security related information (e.g. encryption keys) to the MC service server. The CSC-9 reference point shall use the HTTP-1 and HTTP-2 reference points for transport and routing of security related information to the MC service server. CSC-9 is specified in TS 33.180.

The CSC-10 reference point, which exists between the key management server and the group management server, provides a means for the key management server to provide security related information (e.g. encryption keys) to the group management server. The CSC-10 reference point shall use the HTTP-1 and HTTP-2 reference points and may use the HTTP-3 reference point for transport and routing of security related information to the group management server. CSC-10 is specified in TS 33.180.

The CSC-11 reference point, which exists between the configuration management client and the configuration management server, provides the configuration information required for MC services while the MC service client is off-network. The CSC-11 reference point is the same as CSC-4 reference point except that CSC-11 does not support subscription/notification and therefore does not require the use of SIP-1 and SIP-2 reference points.

The CSC-12 reference point, which exists between the group management client and the group management server, is used for MC service application signalling for data management of the MC service. The CSC-12 reference point is the same as CSC-2 reference point except that CSC-12 does not support subscription/notification and therefore does not require the use of SIP-1 and SIP-2 reference points.

The CSC-13 reference point, which exists between the MC service user database and the configuration management server, is used for:

• the configuration management server to store the user profile data in the specific MC service user database; and
• the configuration management server to obtain the user profile from the specific MC service user database for further configuration in the MC service UE.

The CSC-14 reference point, which exists between the location management client and the location management server, is used by the location management server to receive location information report from location management client. The CSC-14 reference point uses SIP-1 and SIP-2 reference points for transport and routing of subscription/notification related signalling. The CSC-14 reference point uses the HTTP-1 and HTTP-2 reference points for transport and routing of non-subscription/notification related signalling.

The CSC-15 reference point, which exists between the location management server and the MC service server, is used by the MC service server to request and receive location information from location management server. The CSC-15 reference point uses SIP-1 and SIP-2 reference points for transport and routing of subscription/notification related signalling. The CSC-15 reference point uses the HTTP-1 and HTTP-2 reference points for transport and routing of non-subscription/notification related signalling.

The CSC-16 reference point, which exists between two group management servers in different MC systems in different security domains, is used by the group management servers to share group configuration information for MC service groups that can take part in interconnected MC service group calls. The CSC-16 reference point uses the HTTP-1, HTTP-2 and HTTP-3 reference points for transport and routing of non-subscription/notification related signalling. The CSC-16 reference point uses SIP-2 and SIP-3 reference points for transport and routing of subscription/notification related signalling.

The CSC-17 reference point, which exists between configuration management servers in different MC systems in different security domains, is used by the configuration management servers to share user configuration information for MC service users who are permitted to migrate between the MC systems. The CSC-17 reference point uses the HTTP-1, HTTP-2 and HTTP-3 reference points for transport and routing of non-subscription/notification related signalling.

The CSC-18 reference point, which exists between migration management servers in different MC systems, is used by migration management servers to request and provide SIP authentication information for MC service UEs that are permitted to migrate between the different MC systems.

The MCX-1 reference point is defined between MC service servers, between MC service servers and MC gateway servers and between MC gateway servers. The MC service servers and MC gateway servers may be located within one MC system or in separate MC systems. Furthermore, the MC service servers may be of the same type or different types. This MCX-1 reference point is used by MC service servers' coordination procedures (e.g. priority coordination). This reference point is not part of the common service core functionality.

The CSC-19 reference point, which exists between the group management server and MC gateway server is used by the group management server for subscription and notification signalling related to group configuration information that is shared between MC systems to permit interconnection of MC service group calls. The CSC-19 reference point uses the SIP-2 and SIP-3 reference points for transport and routing of subscription/notification related signalling. The SIP-3 reference point is used when a group management server and an MC gateway server, are served by different SIP cores.

The CSC-20 reference point, which exists between configuration management server and MC gateway server is used by the configuration management server for subscription and notification signalling related to user configuration information that is shared between MC systems to permit migration between MC systems. The CSC-20 reference point uses the SIP-2 and SIP-3 reference points for transport and routing of subscription/notification related signalling. The SIP-3 reference point is used when a configuration management server and an MC gateway server, are served by different SIP cores.

The CSC-21 reference point, which exists between MC gateway servers in different MC systems in different security domains, is used to share subscription and notification related signalling for group configuration, user configuration management and location management to permit interconnection and migration between MC systems. The CSC-21 reference point uses the SIP-3 reference point for transport and routing of subscription/notification related signalling.

The CSC-22 reference point, which exists between location management servers in different MC systems, is used to share location information and non-subscription/notification related signalling for location management for interconnected MC systems. The CSC-22 reference point uses the HTTP-1, HTTP-2 and HTTP-3 reference points for transport and routing of non-subscription/notification related signalling.

The CSC-23 reference point, which exists between location management server and MC gateway server, is used to handle location management related signalling. The CSC-23 reference point uses SIP-2 and SIP-3 reference points for transport and routing of subscription/notification related signalling.

The CSC-24 reference point, which exists between the location management server and the configuration management server, to allow the location management server to obtain non-group configuration related information for location service (e.g. policy information). The CSC-24 reference point shall use HTTP-1 reference point and HTTP-2 reference point for transport and routing of non-subscription/notification related signalling. The CSC-24 reference point shall use SIP-2 reference point for transport and routing of subscription/notification related signalling.

The reference points for the SIP and HTTP signalling are described in the following subclauses.

The SIP-1 reference point, which exists between the signalling user agent and the SIP core for establishing a session in support of MC service, shall use the Gm reference point as defined in TS 23.002 (with necessary enhancements to support MC service requirements and profiled to meet the minimum requirements for support of MC service). The SIP-1 reference point fulfils the requirements of the GC1 reference point specified in TS 23.468. The SIP-1 reference point is used for:

• SIP registration;
• authentication and security to the service layer;
• event subscription and event notification;
• communication of the TMGI for multicast operation;
• overload control;
• session management; and
• media negotiation.

The SIP-2 reference point, which exists between the SIP core and the SIP AS for establishing a session in support of MC service, shall use the ISC and Ma reference points as defined in TS 23.002. The SIP-2 reference point is used for:

• notification to the MC service server(s) of SIP registration by the MC service UE;
• authentication and security to the service layer;
• event subscription and event notification;
• communication of the TMGI for multicast operation;
• session management; and
• media negotiation.

The SIP-3 reference point, which exists between one SIP core and another SIP core for establishing a session in support of MC service, shall use the Mm and ICi reference points as defined in TS 23.002. The SIP-3 reference point is used for:

• event subscription and event notification;
• session management; and
• media negotiation.

The HTTP-1 reference point exists between the HTTP client and the HTTP proxy. Between the MC service UE and the HTTP proxy, the HTTP-1 reference point shall use the Ut reference point as defined in TS 23.002 (with necessary enhancements to support specific MC service requirements). The HTTP-1 reference point is based on HTTP (which may be secured using e.g. SSL, TLS).

The HTTP-2 reference point, which exists between the HTTP proxy and the HTTP server, is based on HTTP (which may be secured using e.g. SSL, TLS).

The HTTP-3 reference point, which exists between the HTTP proxy and another HTTP proxy in a different network, is based on HTTP (which may be secured using e.g. SSL, TLS).

The AAA-1 reference point, which exists between the SIP database and the SIP core, is used by the SIP core to retrieve signalling plane data from the SIP database. The AAA-1 reference point utilises the Cx reference point as defined in TS 23.002. In some deployment scenarios the registrar and SIP database are located in the MC service provider's network while the registrar finder is in the PLMN operator's network and the AAA-1 reference point is an inter-network interface.

The AAA-2 reference point, which exists between the SIP core / IMS and Diameter proxy for SIP registration during migration, shall use the Cx reference point as defined in TS 23.002. The AAA-2 reference point is used for:

• authentication and security to the service layer for migration;