Question: In a Cell Broadcast Service (CBS) scenario, as per 3GPP standards, what is a characteristic of the Failure-List provided by the BSC/RNC when it cannot complete a request for certain cells?
Option 1: It contains only successfully targeted cells for CBS messages.
Option 2: Each cell in the list is associated with a 'Cause' and optionally a 'Diagnostic' information element.
Option 3: The list is empty if all cells in a request are successfully processed.
Option 4: It includes a mandatory 'Diagnostic' field for troubleshooting without exceptions.
Explanation: In the context of CBS, when the BSC/RNC is unable to complete a Cell Broadcast Service request for some cells, it provides a Failure-List. This list identifies failed cells, providing a 'Cause' (explaining why the request failed) and optionally a 'Diagnostic' field (for further troubleshooting insights), enabling operators to understand and potentially resolve CBS message delivery issues in those cells.