An apparatus includes an interface connectable to a network, and a controller configured to control a network including UE(s). An uplink connection of the UE(s) is configured on component carrier(s), and a timing advance related instruction with respect to the component carrier(s) is sent to the UE(s), by which validity of the timing advance is changed. An apparatus includes an interface connectable to a network, wherein an uplink connection of the apparatus is configured on component carrier(s), the interface being configured to receive a timing advance related instruction. A controller is configured to change a timing advance validity with respect to the component carrier(s) in response to receiving the timing advance related instruction. Likewise, corresponding methods and computer program products are proposed.