Systems and methods provide component carrier management in carrier aggregation systems. A medium access control (MAC) protocol data unit (PDU) includes an activation/deactivation MAC subheader and an activation/deactivation MAC control element (CE). A plurality of configured carriers are categorized into at least one cell group. Configured secondary cells (SCells) are activated/deactivated according to the activation/deactivation MAC subheader and the activation/deactivation MAC CE.