Thanks but...
But still there is no information on the radar about if it`s what we consider as primary radar in the west. I presume it is a kind of primary radar which doesn`t display received information from an airplane like height and id. I'm not even sure if Tupolev 154 had a transponder. There radar seems to provide information on horisontal and vertical position with a single dot which indicates the plane. No information on height and ID is displayed.