The present patent application discloses a method and apparatus for activating or de-activating a secondary carrier, comprising informing a serving radio network controller when a secondary carrier was activated or de-activated, receiving a confirmation from the serving radio network controller that non-serving NodeB cells have achieved synchronization, and scheduling a UE upon receiving confirmation. In another example, the present patent application discloses a method and apparatus for de-activating a secondary carrier, comprising controlling de-activation of the secondary carrier using high-speed shared control channel orders, receiving acknowledgement of said high-speed shared control channel orders, and informing a serving radio network controller when the secondary carrier was de-activated.