so… let me decode :
1/ incoming HO very low = incoming HO success rate is very bad ?
2/ there is now interference = there NO interference ???
3/ there is a village under mountain = the village is buried under the mountain ?
basically your quetion is: what are the possible causes of poor inc HO success %
– poor coverage
– interference on one TRX
– same BCCH/BSIC or TCH/BSIC as a nearby cell
– hardware failure on a TRX or a combiner (path balance issue)
if nothing works, identify what is the “outgoing” serving cell and perform a drive test along the main roads from serving to target.