A method for selecting one or more secondary cells, SCells for supporting communication with a user equipment, UE, by carrier aggregation, CA. The one or more SCells is/are selected from a set of SCell candidates available for an access node. The method includes estimating a probability that the UE connected to a primary cell, PCell, of the access node is in coverage of an SCell in the set of candidates, predicting available resources for the SCell, calculating a CA value for the SCell based on the estimated probability, an estimated spectral efficiency and the predicted available resources, and calculating a CA value for each SCell of the set of SCell candidates, ranking the SCells of the set of SCell candidates based on their calculated CA values, and selecting one or more SCells for providing CA with the UE based on the ranking.