There is provided mechanisms for controlling total average transmission power of a radio base station over a fixed time period. A method is performed by a control device. The method comprises obtaining values of average total transmission power of at least one previous transmission from the radio base station. The method comprises determining a resource factor value from the value of average total transmission power and a set point value of the average total transmission power. The method comprises determining, based on the resource factor value, an action that restricts the amount of code-division multiple access (CDMA) resources to be used at least for a current transmission. The method comprises controlling the total average transmission power over the fixed time period by initiating the determined action at least for the current transmission.