Question: What is a prerequisite for a User Equipment (UE) to support RRC Connection Re-establishment for the Control Plane CIoT 5GS Optimisation in an E-UTRA network?
Option 1: The UE must support LTE Cat-M only.
Option 2: The UE must be connected to a 4G network exclusively.
Option 3: The UE's manufacturer must have implemented a proprietary CIoT protocol.
Option 4: The UE must also support NB-IoT/5GC and have a ue-Category-NB.
Explanation: For a UE to support RRC Connection Re-establishment for the Control Plane CIoT 5GS Optimisation, it requires two key conditions: supporting NB-IoT/5GC for compatibility with narrowband IoT and 5G core network standards, and having a ue-Category-NB, signifying the UE's capability to operate within narrowband categories, ensuring efficient resource utilization for CIoT applications optimized for control plane in 5GS.