There is provided support mechanisms for at least one adding and removing a cell from operation in a heterogeneous radio network having a first type of basic cell for providing basic radio coverage and a second type of cell associated to a basic cell as a capacity enhancing cell. A capacity enhancing cell is selectively switched on and off (S1); when the capacity enhancing cell is shut down the cell does not exist over the air while cell configuration information is kept and when the capacity enhancing cell is switched on the cell becomes available again over the air interface. An indication of shut-down and a wake-up call message for switch-on of the capacity enhancing cell are communicated (S2) between a base station serving the capacity enhancing cell and a base station serving the basic cell. In this way energy savings can be supported without disrupting service availability.