Priority-Based Re-selection

Technical Explanation

In SIB4 and SIB5, carrier frequencies are assigned absolute integer priorities (0 to 7). A UE continuously attempts to reselect to a higher-priority carrier if its signal quality exceeds Thresh_high. It only reselects to a lower-priority carrier if the serving cell drops below Thresh_serving_low and the candidate exceeds Thresh_low.

Key Functions

• Governs multi-layer frequency mobility based on absolute carrier tiers (0-7)
• Forces UEs to camp on high-capacity mid-band/mmWave whenever available
• Provides controlled offloading to coverage layers when capacity fades