1) Fault location to the abnormal TCH release (all possible reasons)
If the difference between "TCH performance measurement -> TCH seizure requests (total)" and "TCH performance measurement -> Successful TCH seizures (total)" is greater than 50, the radio link alarm is caused by the abnormal TCH release.
2) Fault location to the abnormal TCH release caused by the low success rate of the TCH assignment
“TCH seizure requests (handover not included)” – “Successful TCH seizures (handover not included)” = Times of the abnormal TCH releases caused by low success rate of the TCH assignment.
3) Fault location to the abnormal TCH release caused by the low success rate of incoming cell handovers
The low success rate of incoming cell handovers is classified into the low success rate of incoming internal inter-cell handovers and the low success rate of incoming external inter-cell handovers.
a. Number of abnormal TCH releases (internal incoming cell handover) = TCH seizure requests (internal incoming cell handover) – Successful TCH seizures (internal incoming cell handover).
b. Number of abnormal TCH releases (external incoming cell handover) = TCH seizure requests (external incoming cell handover) – Successful TCH seizures (external incoming cell handover).