Question: What is a prerequisite for the Mobility Management (MM) information procedure to be performed between the Visitor Location Register (VLR) and the Mobility Management Entity (MME) via the SGs interface, in terms of UE attachment?
Option 1: The UE must be IMSI attached only to EPS services.
Option 2: The UE must be IMSI detached from both EPS and non-EPS services.
Option 3: The UE's SGs association state must be SGs-UNASSOCIATED at the VLR but SGs-ASSOCIATED at the MME.
Option 4: The UE must be IMSI attached to both EPS and non-EPS services, with an SGs association state of SGs-ASSOCIATED.
Explanation: This is correct because the MM information procedure's execution between VLR and MME via the SGs interface requires the target UE to have simultaneous attachments to both EPS (Evolved Packet System) and non-EPS services, indicating a dual-mode capability or requirement, with the SGs association being in an associated state to facilitate this communication. This ensures seamless management across different service types.