A method and system for selectively activating and deactivating secondary cells in a wireless communication system are disclosed. According to one aspect, the invention provides a finite state machine having a plurality of states facilitating secondary cell activation and deactivation decisions. The states of the finite state machine include a deactivated state and an activated state. In the deactivated state, a secondary cell is deactivated and a media access control element, MAC CE, for deactivation is sent to the UE. The base station in the deactivated state is not allocating resources for maintaining transmission on the secondary cell. In the activated state, the secondary cell is active and a MAC CE for activation is sent to the UE. In the activated state, the base station is ready to transmit on the secondary cell.