Question: When does the Mobile Equipment (ME) inform the Universal Integrated Circuit Card (UICC) of a change in its current Closed Subscriber Group (CSG) or Hybrid cell selection status?
Option 1: Periodically, based on a timer set by the last SET UP EVENT LIST command.
Option 2: Only when explicitly requested by the UICC via a specific command.
Option 3: Upon every power cycle of the ME, to ensure synchronization.
Option 4: When the ME detects an actual change in its current CSG or Hybrid cell selection status, given that the CSG Cell Selection event is part of the current event list.
Explanation: This option correctly reflects the condition under which the ME notifies the UICC about changes in CSG or Hybrid cell selection status. It requires two conditions to be met: the CSG Cell Selection event must be included in the current event list, and an actual change in the cell selection status must occur. This ensures efficient communication between the ME and UICC, only triggering when relevant changes happen.