TSG CT WG4(MAP/CAMEL/GTP/BCH/SS/TrFO/IMS/GUP/WLAN)

Terms of Reference

Approved at 3GPP TSG#28 Meeting, Quebec City, Canada, 1 - 3  June 2005
 

Introduction

The updated ToR, reflecting the re-organisation of the 3GPP TSGs in March 2005, were agreed by the Working Group CT4 and were submitted to the CT#28 (Jun 2005) plenary meeting for approval.

Background

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.
 

Terms of Reference

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);
• Profiling of Call/Transport Control Protocols defined outside 3GPP to be used within the Core Network (e.g. BICC, RTP);
• Stage 3  of  MGW control protocol and profile definition (H248 based);
• Stage 3 (between network entities) of GPRS;
• 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  Multimedia Messaging Service (MMS).

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;
• SIP-T;
• Subscriber Data Management in HSS and HSS-CSCF Diameter application protocols to support it;
• Subscriber data management in HSS and HSS-CSCF 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 in line 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.