Question: What happens when an IMS network receives an indication of GRUU support for a specific Public User Identity from a UE during a registration request, in terms of generating GRUUs for implicitly registered Public User Identities?
Option 1: The IMS network generates P-GRUU's and T-GRUU's only for the explicitly registered Public User Identity.
Option 2: The IMS network does not generate any GRUUs for implicitly registered Public User Identities.
Option 3: The IMS network generates P-GRUU's and T-GRUU's for all implicitly registered Public User Identities belonging to the same implicit registration set and communicates them to the UE.
Option 4: The IMS network generates only P-GRUU's for implicitly registered Public User Identities but not T-GRUU's.
Explanation: When an IMS network receives a GRUU support indication for a specific Public User Identity during registration, it generates and communicates P-GRUU's and T-GRUU's for all implicitly registered Public User Identities in the same implicit registration set to the UE, ensuring comprehensive GRUU support across relevant identities.