IP Multimedia Subsystem (IMS) subscription and access scenarios
This document studies scenarios between subscribers and operators, mainly from IMS subscriptions point of view and verifies the compatibility of the possible scenarios within 3GPP Scope. Release 6 includes several work items like IMS enhancements, WLAN interworking that needs to be better understood so that clear requirement can be agreed and relevant technical specifications can be developed in time.
The document will identify the requirements arising from the following issues:
• Identification of requirements for 3GPP operators to implement only some of 3GPP system domains? (For example an IMS system separated from the PS domain and access network. What is the relationship between the AN/CN/IMS networks in this case? Are there conflicts in privacy issues due to several subscriptions?)
• Operator control of networks used to access / provide IMS services. For example operator may want to limit the subscriber to access the IMS via a specific 3GPP access network.
• Non-3GPP access network implications.
• Simultaneously access to IMS by one user with multiple devices. .
• UE functionality split (if any implications).
• Deployment of UICC with several USIM and ISIM applications from different parties.
• Analyse aspects of user interaction when activating USIM and ISIM applications on the UICC (e.g. manually, automatically, PIN, NON-PIN).
Below issues need to be described in scenarios :
• Generic issues
• Security
• Charging
• Privacy
• Roaming
• Regulatory (e.g lawful interception) etc.
• Quality of service
• User experience
Further TR needs to translate the scenarios, which fit in the scope of the 3GPP system to 3GPP service requirements.
Criteria for requirements to be included:
1. In scope with 3GPP access (UTRAN, GERAN) or access that 3GPP has specified interworking with (WLAN).
2. In scope with 3GPP core network(s).
3. In scope with 3GPP enabling technologies.
4. Scope of this work is limited to identify service requirements derived from scenarios capturing various business requirements. No architectural solutions will be considered in this TR.
Note: 3GPP should not place requirements, which would prohibit the possibility to use non-3GPP defined access for IMS.
Note: The SA2 within its own documentation shall look into technical feasibility and architecture implications of scenarios and requirements defined by SA1 and contact SA3 and SA5 for deeper technical understanding if necessary. Overall architecture implications shall consider also UICC implications (e.g. if it is appropriate to have several ISIMs on one UICC and possibility of having empty field for either ISIM or USIM in a UICC.?) and accordingly contact T3 for deeper technical understanding if necessary.