Yes, if the candidate target is congested, the fast traffic ho will fail due to congestion.
But I must disagree with you : the HO inc fail due to congestion is NOT a KPI !!
HO congestion means the BSC detects a HO, and check for available candidate. If it doesn’t find the candidate is congested, what is actually the impact for the subscriber ? Not being able to setup the call ? So it is as if fast traffic HO is disabled… >> call setup fails.
But sometimes, the BSC finds a candidate with a free TCH >> call setup succeeds.
Altogether, you increaase the probability of call setup success, even though you artificially increse the inc HO congestion.
The KPI for HO is actually “outgoing HO execution success rate”, which doesn’t take into account congestion failures.