The TSG Core Network and Terminals WG3 (TSG CT WG3) specifies the bearer capabilities for circuit and packet switched data services, and the necessary interworking functions towards both, the user equipment in the UMTS PLMN and the terminal equipment in the external network. In addition CT is responsible of end to end QoS for the UMTS core network in Release 5 and beyond.

Useful links and information

Terms of reference

Link to terms of reference (CP-110741.zip) updated at TSG#53 in Fukuoka, Japan, in September 2011.

CT3 is responsible for:

1. Interworking between a 3GPP PLMN and external nodes or networks, interworking between PLMNs as well as interworking between PLMN domains. 2. Policy and charging control, end-to-end QoS mechanisms.

Areas of responsibility

• CS domain
• Transport protocols from the core network towards the UE, incl. rate adaptation and RLP.
• Data call signalling parameters from the core network towards the UE.
• Control plane and user plane interworking towards the fixed network.
• User plane protocols between MGWs (Nb interface)

• PS domain and WLAN
• Interworking between GPRS/EPS and external IP networks including enterprise. networks. Stage 2 and stage 3 responsibility for bearer level and AAA and DHCP functionality.
• Interworking between WLAN and external IP networks, incl. bearer level and AAA functionality.
• Providing presence information to the Presence Network Gateway from access network (e.g GPRS and WLAN) gateways.
• Interworking between access network gateways and service networks/nodes, incl. MBMS SGmb/Gmb interfaces.
• R reference point (TE – MT) related to the PDP context de/activation (scope of TS 27.060), incl. general requirements for AT commands

• IM CN subsystem (IMS) of the PS domain
• Interworking with CS networks
• Interworking with external IP networks
• Bearer related network entities, e.g. IM-MGW, TrGW
• NGN related interworking impacts
• Inter-IMS protocol profiles and procedures
• Services
• Circuit switched data services, incl. multimedia, facsimile and text telephony
• Service Change and UDI Fallback (SCUDIF), stage 2
• Service interworking
• Policy and Charging Control, QoS
• Service Based Local Policy within a PLMN and between a PLMN and external Application Functions
• QoS mapping between service layer and access network bearer layer
• End-to-end QoS mapping and negotiation
• Usage of QoS protocols (such as DiffServ, RSVP and NSIS)
• Provisioning of charging rules and charging policies at access network gateways
• User layer application detection and related control functionality
• PCRF interactions with the online charging system

3. Dependencies with other groups

CT3 has important dependencies with the following work performed in other 3GPP groups:

• CT1: The radio interface layer 3 procedures and protocols, IMS signalling
• CT4: Diameter coordination, stage 2 for the split CS architecture and TrFO, Mc and Mn and Ix interfaces, GTP, PMIP, DSMIP
• RAN3: Iu-cs interface
• SA1: Service requirements
• SA2: Overall architecture
• SA4: PS services e.g. MBMS user services, conversational services used in IMS
• SA5 SWG B: Gy interface for Flow Based Charging

Furthermore, CT3 has important dependencies with work performed in the following external entities: ITU-T, IETF, ETSI TISPAN and Broadband Forum.

4. Specifications

CT3 is responsible for the technical specifications and reports listed under the following link: http://www.3gpp.org/ftp/Specs/html-...