A method in a wireless communication terminal including monitoring a terminal specific search space of a first Component Carrier (CC) from a base unit, wherein the search space corresponds to a set of Physical Downlink Control CHannel (PDCCH) candidates monitored by the terminal for PDCCH messages, and receiving an activation message on the first CC, wherein the activation message activates at least one additional CC. The size of the search space monitored by the terminal after receiving the activation message is greater than the size of the search space monitored before receiving the activation message.