A technique, including initiating an access procedure by making from a communication device an uplink transmission on one component carrier of a plurality of component carriers associated with an access node; thereafter receiving at said communication device group information specifying a group of said plurality of component carriers sharing uplink transmission timing information as a group to which said one component carrier belongs; and making from said communication device a further uplink transmission on said one component carrier using uplink transmission timing information for said group specified in said group information.