3GPP Work Item description

This page contains informal descriptive text only.  See master WID page for further details.

Feature: Behaviour of Multi system UEs

Currently it is not standardised how a multi system terminal should perform system selection. Multi system terminals are appearing on the market.

Objective: 

It is proposed that SA1 should study the best way to document the behaviour of a multi system terminal that supports both 3GPP and non-3GPP systems. This will be documented in a new Technical Report. The distinction between 3GPP internal PLMN selection requirements and multi system selection requirements should be kept clearly visible.  

It should be identified clearly which requirements are mandatory and which can be left implementation specific. Standardization should take account of interoperability and network protection. The intention is to ensure that the multi system operation does not lead to non 3GPP-compliant behaviour by the terminal.  

Particular issues to be handled include, but are not restricted to:  

    §         It should be studied whether the system selection or PLMN selection should take higher priority in a multi system terminal. Related to this, the criteria for system change would need to be defined. This could take the form of a background scan of higher priority systems. If this is supported the interaction between the user's and the operator's preferences should be studied. The existing PLMN selector lists and HPLMN information could be re-used in system selection.

    §         It should also be considered whether automatic or manual system selection mode, or both, needs to be supported. The study will identify different methods of system selection and their impact on 3GPP specifications.

    §         If any priority lists for user's preferences, supported systems or network operators are needed, it should be studied if these should reside in the terminal memory or in the smartcard. When dealing with the 3GPP-compliant part of the terminal, we can safely assume the UICC to be available.

    §         Testing of multi-mode terminals, in particular the mechanisms for system selection will be considered. The study will consider what needs to be tested and by whom.

Other groups working in this area will be consulted.

Service Aspects:

This work item will consider the impact of changing system on the end services provided to the user.