The TSG Core Network and Terminals WG4 (TSG CT WG4) standardizes stage 2 and stage 3 aspects within the Core Network focusing on Supplementary Services, Basic Call Processing, Mobility Management within the Core Network, Bearer Independent Architecture, GPRS between network entities, Transcoder Free Operation, CAMEL, Generic User Profile, Wireless LAN - UMTS interworking and descriptions of IP Multimedia Subsystem. CT4 is also responsible as a "protocol steward" for the some IP related protocols (this involves analyzing, validating, extending if necessary, clarifying how they are used, specifying packages and parameter values).
Election for 1 Vice Chairman of CT4 to be held in May 2012.**
Useful links and information
| About TSG CT4 | List of elected officials |
| Documents | Meeting documents |
| Specifications | |
| Work items | |
| Meetings | Next meeting information & previous meeting reports and documents |
| Liaisons Statements | |
| Full CT4 meeting calendar | |
| General info | 3GPP IETF Dependencies - from TSG#52 Jun 2011 onwards the 3GPP-IETF Dependencies are included in the 3GPP Work Plan |
| Email exploder lists |
| CT Working groups | |
|---|---|
| TSG CT Plenary | |
| TSG CT WG1 | MM/CC/SM (lu) |
| [No WG2] | See Old Terminals Group 2 |
| TSG CT WG3 | Interworking with external networks |
| TSG CT WG4 | MAP/GTP / BCH/SS |
| TSG CT WG5 | OSA (Now transferred to OMA) |
| TSG CT WG6 | Smart Card Application Aspects |
Terms of reference
The updated ToR were approved in CT#51, March 2011 plenary meeting.
3GPP TSG CT WG4 (CT4) is responsible for the standardization of the stage 2 aspects within the Core Network including: Supplementary Services, Basic Call Processing, Mobility Management within the Core Network, Bearer Independent Architecture and CAMEL. CT4 is also responsible for the specification of the mobile specific protocol specifications within the mobile core network. A number of protocols within the core network are specified by external bodies such as: the ITU-T, IETF and Liberty Alliance Project. In these cases, CT4 are involved in “profiling” (describing how and which part of these “external protocols” are to be used, describing protocol interworking between 3GPP specified protocols and these external protocols). 3GPP CT4’s mandate is to specify the protocols within the Core Network including specifications describing the protocol requirements. CT4 is responsible for the following core network feature specifications:
- Stage 2 and (jointly with CT3) stage 3 specifications of the Bearer Independent Architecture,
- Stage 2 and stage 3 (between Core Network entities) of Mobility Management within the Core Network;
- Stage 2 and stage 3 (between Core Network entities) of Circuit-Switched Call Control within the Core Network (e.g. Basic Call Handling);
- Stage 2 of restoration procedures of Core Network entities
- Profiling of Call Control Protocols defined outside 3GPP to be used within the Core Network (e.g. BICC, SIP-I);
- Stage2 (jointly with CT3) and Stage 3 of MGW control protocol and profile definition (H248 based);
- Stage 3 (between network entities) of GPRS (e.g Interfaces based on GTP);
- Stage 3 (between network entities) of EPC (e.g. Interfaces based on GTP and PMIP);
- Stage 2 and stage 3 of Supplementary Services;
- Stage 2 and stage 3 of Mobile Number Portability;
- Stage 2 and stage 3 of Subscriber Data Management;
- Stage 2 and stage 3 of Transcoder Free Operation (TrFO) (in conjunction with SA4);
- Stage 2 and stage 3 of CAMEL;
- Stage 3 of Location Services;
- Stage 3 of Security;
- Stage 3 of WLAN – UMTS interworking;
- Stage 3 of Subscriber Certificates;
- Stage 2 (jointly with SA2) and stage 3 of Generic User Profile (GUP);
- Stage 3 (jointly with CT3) descriptions of IP Multimedia Subsystem (IMS); and
- Stage 3 on DNS procedures within 3GPP CT4 is responsible as a “protocol steward” for the following IP related protocols (this involves analyzing, validating, extending if necessary, clarifying how they are used, specifying packages and parameter values):
- AAA protocols;
- security protocols;
- Sigtran;
- Subscriber Data Management in HSS and HSS-Core Network entities and protocols to support it;
- DIAMETER protocol codes; Requesting application IDs from IANA
- AVP result codes and Reserving AVP codes from the 3GPP specific range
- Experimental result codes. Reserving experimental result codes from the 3GPP specific range The above list of standardization activities is not exhaustive and activities can be deployed within CT4 as long as they are inline with the mandate given by the CT plenary. In general, 3GPP CT4 interacts with all 3GPP WGs, but with the following specifically:
- 3GPP TSG SA WG1(SA1); SA1 defines the requirements for CAMEL in the stage 1 specification. The CAMEL work of CT4 is based on the SA1 requirements.
- 3GPP TSG SA WG2 (SA2); SA2 is responsible for the high-level architecture specifications of the whole network (including the CT). CT4 is responsible for the detailed description of parts of this architecture related to CT internal functions and protocols.
- 3GPP TSG CT WG1 (CT1); CT1 is responsible for the call control, mobility management, and session management aspects across the radio interface. These aspects have impacts on the CT4 specifications, such as stage 2 Call Control, Supplementary Services, Handover, etc. On these aspects CT4 will collaborate closely with CT1.
- 3GPP TSG CT WG3 (CT3); CT3 is responsible for the network interworking aspects and user plane protocols (except GTP). CT3 is responsible for the parameter values of the Media Control Protocols (MCP) and the Bearer Control protocols. These activities have impacts on the activities within CT4 and therefore CT4 will closely collaborate with CT3 on these aspects. This list of 3GPP WGs is not exhaustive; CT4 will maintain liaison with other 3GPP WGs as needed.
