Question: What is the required range for timer TR1M when a Mobile Station (MS) operates in Narrow Band (NB) modes, specifically NB-S1 mode or NB-N1 mode, with control plane CIoT optimization?
Option 1: Greater than 195 seconds and less than 205 seconds
Option 2: Greater than 35+360 seconds and less than 45+360 seconds
Option 3: Exactly 300 seconds for both NB-S1 and NB-N1 modes
Option 4: Less than 100 seconds for NB-S1 mode and greater than 200 seconds for NB-N1 mode
Explanation: According to specifications, timer TR1M for control plane CIoT optimization in EPS services with NB-S1 mode, or 5GS services with NB-N1 mode, should be set between greater than 35+360 seconds and less than 45+360 seconds. This balances reliable message delivery and prevents undue network delays in these optimized narrowband modes.