Yes Safar, LOL is based on the path loss criteria. Now assuming you are using BSTXPWR=43 (1800), with LOL=140 and LOLHYST=3
We will get following values.
1) UL to OL (Handover Border) will be, Rxlevel (DL) >= -[140-3-43].
Rxlev(DL) >= -94.
(Now this means your UL will try to handover call to OL even if RXlevel are as low as -93,-94 dbm. This means that rxlev at OL will be even lesser due to higher pathloss of higher frequencies. This will decrease your assignment to OL success rates.
2) FBOFFS is used to decide when will the OL handover the call to UL. (It can be eliminated if you include the OWN BCCH frequency in the active MF LIST).
If not using FBOFFS but including own BCCH in active MF List, following formula is used
Rxlevel(DL) < -(LOL + LOLHYST - BSTXPWR) Rxlevel(DL) < -(140+3-43) Rxlevel(DL) < -(100) 3) Now, as you can see, the borders of UL OL are UL to OL -> -94 dBm
OL to UL -> -100 dBm.
Although the OL to UL limit seems somewhat reasonable, UL to OL is far too stretched. This will be degrading KPIs of your cells.
You should, make the UL to OL limit somewhere near -80->-85dBm and OL to UL limit -99 dBm. This will give you a nice balance between subcell utilization and call drop rates.