On BSC level there are two parameters which control these statistics. LOWSSDL and LOWSSUL.
If at the time of drop DL_RXLEV is lower than LOWSSDL then it is considered as “Drop due to Low SS DL” similarly if UL_RXLEV is less than LOWSSUL “Drop due to Low SS UL” and if both are low then “Drop due to Low SS Both Links”
But please keep in mind that these parameters only affect the Drop Reasons statistics, not the actual number of drops. As none of the stats mentioned by Pix are available in Ericsson so you may initiate a CTR(cell traffic recording) to troubleshoot the issue. It will tell you the radio conditions and TA before the drop occurred and will help you to sort out the problem hopefully.
Following commands can be used to change the parameters:
RAEPC:PROP=LOWSSDL-value;
RAEPC:PROP=LOWSSUL-value;
where vaue can be anything from 47 to 110 (negative dBm)