Question: What type of procedures does a User Equipment (UE) perform during idle mode mobility from 5G System (5GS) to Evolved Packet System (EPS) over N26 interface?
Option 1: Detach and Re-attach procedures
Option 2: Tracking Area Update (TAU) procedure or Initial Attach procedure
Option 3: Handover and Redirection procedures
Option 4: Authentication and Authorization procedures
Explanation: During idle mode mobility from 5GS to EPS over N26, the UE performs either a Tracking Area Update (TAU) procedure to update its location or an Initial Attach procedure to establish a new connection. This is necessary for the UE to maintain connectivity and receive services in the new network.