Question: What happens to non-emergency EPS bearers when a UE's CSG subscription expires or is removed while receiving emergency bearer services from a CSG cell?
Option 1: The MME deactivates all EPS bearers, including emergency and non-emergency.
Option 2: The MME does not deactivate any EPS bearers.
Option 3: The MME deactivates all non-emergency EPS bearers but keeps the emergency EPS bearers active.
Option 4: The UE is disconnected from the PDN.
Explanation: According to the EPS bearer context deactivation procedure, if a UE is receiving emergency bearer services from a CSG cell and the CSG subscription expires or is removed, the MME shall deactivate all non-emergency EPS bearers but keep the emergency EPS bearers active. This ensures that the UE remains connected for emergency services while other non-essential services are terminated.