The invention relates methods for triggering channel quality feedback for at least one of plural component carriers of a communication system available for downlink transmission. The invention suggests a mechanism for triggering channel quality feedback from a terminal where the downlink control signaling overhead for the selection of component carrier(s) to be reported on is minimized. One aspect of the invention is a new interpretation of a predetermined format for dedicated control information comprising a CQI request flag, which is depending on the status of the CQI request flag. In case the CQI request flag is set at least one further bit of the dedicated control information is interpreted as information indicative of the one or more component carriers available for downlink transmission to the terminal and the terminal is providing channel quality feedback on the channel quality experienced on the indicated component carrier or component carriers.