Question: In a scenario where a subscriber has multiple subscriptions (e.g., multiple ISIM or USIM applications on the UICC), how are Generic User Security Settings (GUSSs) mapped to private identities in the Home Subscriber Server (HSS)?
Option 1: One GUSS can be mapped to multiple private identities, and one private identity can have multiple GUSSs.
Option 2: One GUSS is exclusively mapped to one private identity, with no sharing or duplication.
Option 3: Multiple GUSSs can be mapped to one private identity, but each GUSS is unique to that identity.
Option 4: Each of the existing GUSSs shall be mapped to one or more private identities (e.g., IMPIs and IMSIs), but each private identity shall only have zero or one GUSS mapped to it.
Explanation: This is correct because, according to the specifications, the HSS allows for flexibility in mapping where a single GUSS can serve multiple identities (to accommodate various subscriptions), yet ensures uniqueness by restricting each private identity to either no GUSS or just one. This setup supports complex subscription scenarios while maintaining clarity and security at the individual identity level.