A message for reporting a channel quality of a communication system supporting carrier aggregation and operation on multiple component carriers, the message comprising: a first channel quality field consisting of a known number of bits and containing a plurality of channel quality measures, each channel quality measure providing a channel quality measure of a respective component carrier of a plurality of component carriers available for communication between a base station and a terminal, wherein the first channel quality field consists of a number of sub-fields, wherein each sub-field is associated to a respective component carrier and wherein the number of sub-fields is defined by the number of component carriers available for communication between a base station and a communication terminal, and a second channel quality field consisting of a variable number of bits, wherein the number of bits and structure of the second channel quality field is indicated by the content of the bits of the first channel quality field, wherein each channel quality measure of the first channel quality field indicates whether or not a further second channel quality measure for a respective component carrier is present in the second channel quality field, wherein a channel quality measure of a respective component carrier comprised in the first channel quality field consists of a wide band modulation and coding scheme indicator and/or a wide band rank indicator and no further channel quality measure of said component carrier is comprised in the second channel quality field, if the wideband modulation and coding scheme indicator or the wideband rank indicator for the component carrier indicates "out of range" or "undefined", wherein the rank indicator indicates the rank of the transmission matrix to be employed for multi-antenna transmission. a first channel quality field consisting of a known number of bits and containing a plurality of channel quality measures, each channel quality measure providing a channel quality measure of a respective component carrier of a plurality of component carriers available for communication between a base station and a terminal, wherein the first channel quality field consists of a number of sub-fields, wherein each sub-field is associated to a respective component carrier and wherein the number of sub-fields is defined by the number of component carriers available for communication between a base station and a communication terminal, and a second channel quality field consisting of a variable number of bits, wherein the number of bits and structure of the second channel quality field is indicated by the content of the bits of the first channel quality field, wherein each channel quality measure of the first channel quality field indicates whether or not a further second channel quality measure for a respective component carrier is present in the second channel quality field, wherein a channel quality measure of a respective component carrier comprised in the first channel quality field consists of a wide band modulation and coding scheme indicator and/or a wide band rank indicator and no further channel quality measure of said component carrier is comprised in the second channel quality field, if the wideband modulation and coding scheme indicator or the wideband rank indicator for the component carrier indicates "out of range" or "undefined", wherein the rank indicator indicates the rank of the transmission matrix to be employed for multi-antenna transmission.