Handover failure: too early, too late, wrong cell — HO failure classification

Too Late and Too Early HO

The 3GPP defines three categories of handover failures that directly point to the parameter adjustment needed. Too Late Handover occurs when the UE experiences RLF on the source cell before or during handover execution — the serving cell degrades before the A3 condition triggers or the TTT is too long. The UE re-establishes on the cell it should have handed over to. Fix: reduce A3 offset and/or reduce TTT. Too Early Handover means the HO completes successfully but the UE experiences RLF on the target cell shortly afterward (typically under 1 second) and re-establishes back on the original…