It is provided a method, comprising detecting a trigger; estimating, for each of one or more deactivated helper cells, a respective estimated transferred load if the trigger is detected, wherein the respective estimated transferred load will be transferred from a reference cell to the respective helper cell if the respective helper cell will be activated, and the one or more deactivated helper cells belong to a power saving group consisting of the reference cell and one or more helper cells; determining determine a candidate cell among the deactivated helper cells, wherein the estimated transferred load of the candidate cell is maximum among the estimated transferred loads; instructing activating of the candidate cell.