Periodic Registration

Technical Explanation

Even when stationary, a UE must periodically notify the core network that it remains alive and in coverage. The UE runs timer T3512 (typically 54 minutes). When T3512 expires, the UE sends a Periodic Registration Request. If missed repeatedly, the AMF marks the UE as detached (RM-DEREGISTERED).

Key Functions

• Supervised by periodic timer T3512 (typically 54 minutes)
• Confirms UE availability and coverage presence to the core network
• Prompts AMF to purge inactive UE context if keepalive fails repeatedly