R-Criterion

Technical Explanation

When evaluating intra-frequency or equal-priority inter-frequency cells, the UE ranks candidate cells: Serving Cell Rank Rs = Qmeas,s + Q_hyst; Neighbor Cell Rank Rn = Qmeas,n - Q_offset. If a neighbor cell maintains Rn > Rs for duration Treselection, the UE re-selects to that neighbor.

Key Functions

• Ranks neighbor cells against serving cell using hysteresis and offsets
• Prevents ping-pong re-selections via hysteresis parameter Q_hyst
• Directs UE to the best radio channel during idle/inactive mobility