The present invention relates to methods at a base station of changing Radio Access Technology (RAT) of a mobile terminal in a communications network, and related base stations performing the methods. In one embodiment, a change to be made from a serving RAT to a first target RAT is determined, and a quality measure of the first target RAT is estimated based on a quality measure of the serving RAT. The mobile terminal is instructed to change to the first target RAT responsive to determining that the estimated signal quality measure of the first target RAT exceeds a quality threshold value.