ETSI TR 122 937

The present document develops the use cases and requirements for service continuity between a 3GPP network and another network, which can be:

• a TISPAN NGN with an IMS, accessed by a WLAN.
• an ISP accessed via a WLAN

Each access network has its own separate security system and the NOs have a commercial agreement for roaming and handover.

The present document considers use cases whereby:

Editors Note: Text to be added when use cases are agreed

The present document also examines the requirements and implications of:

• service aspects: maintaining service quality and service continuity, while roaming between a 3GPP PLMN and an independently-owned WLAN;
• security aspects: while roaming between a 3GPP PLMN and a WLAN, in particular when networks may be independently authenticated.
• UICC aspects, including NAA types, personalisation and ownership.

The present document is related to ongoing standardisation efforts in the following areas:

• where the WLAN is an I-WLAN , requirements for which are described in [3];
• methods for selecting the 3GPP or the non-3GPP access network, requirements for which are described in [2].