Question: What is a prerequisite for an MME (Mobility Management Entity) to be in the LOCATION State when requesting a location service for a User Equipment (UE)?
Option 1: The UE must be in idle mode with no active connections.
Option 2: A Mobility Management connection to the UE must be active and the UE known in the MME.
Option 3: The E-SMLC (Evolved Serving Mobile Location Centre) must have previously initiated a location service for the UE.
Option 4: The UE must be undergoing a handover procedure to a new cell.
Explanation: In the LOCATION State, the MME is awaiting a response from an E-SMLC after requesting a location service. For this process to initiate and for the MME to be in this state, it logically requires an active Mobility Management connection to maintain communication with the UE and for the UE's details to be recognized by the MME.