When positioning the 4KPR-15R personal cell repeater, the big foot side of the repeater unit faces the room where you desire enhanced coverage. The repeater unit does not need line of sight to the window. Rather, it must face away from the window, and be at least 8' to 12' from the window antenna. The big foot side of the repeater unit must always face the room, not the window.
4KPR-15R Personal Cell Repeater