Question: What are the two procedures required for notifying a service-related entity about the reachability of a User Equipment (UE) at the Evolved Packet Core (EPC) Non-Access Stratum (NAS) level?
Option 1: UE Reachability Request and UE Activity Indication
Option 2: UE Reachability Notification Request and UE Activity Notification
Option 3: UE Availability Request and UE Reachability Confirmation
Option 4: UE Presence Notification and UE Activity Report
Explanation: The correct answer is Option 2 because the two procedures required for notifying a service-related entity about the reachability of a User Equipment (UE) at the Evolved Packet Core (EPC) Non-Access Stratum (NAS) level are indeed the UE Reachability Notification Request procedure and the UE Activity Notification procedure. These procedures enable the service-related entity to be informed about the UE's reachability status, which is essential for various services and applications in the telecom network.