Methods and apparatus are provided for controlling activation or deactivation of a carrier frequency in a multi-carrier/cell system. Activation or deactivation of a subsidiary carrier frequency is determined according to a parameter associated with the subsidiary carrier frequency. When the subsidiary carrier frequency is to be activated or deactivated, a message, such as an HS-SCCH order, is transmitted to a terminal to instruct the terminal to activate or deactivate the subsidiary carrier frequency. In this manner, a certain carrier frequency can be flexibly activated or deactivated in accordance with real-time assessment of multi-carrier/cell conditions.