Question: What is a key aspect of the 3GPP Single Sign-On (SSO) Service when a user transitions between 3GPP and non-3GPP access networks during an active data application session?
Option 1: The service requires the user to re-authenticate using Operator-controlled credentials.
Option 2: The transition is transparent from a user perspective, maintaining the ongoing session.
Option 3: The 3GPP SSO Service automatically switches to an alternative authentication method.
Option 4: The data application session is terminated, and the user must restart it.
Explanation: This correct answer highlights a crucial service principle of the 3GPP SSO Service, emphasizing seamless user experience. Transparency during network transitions (between 3GPP and non-3GPP access) ensures that the user's active data application session remains uninterrupted, reflecting the service's design for user convenience and continuity.