A wireless device receives control messages comprising configuration parameters of a plurality of carriers comprising at least one backward compatible carrier and at least one non-backward compatible carrier. The control messages comprise information indicating a carrier type and information associating at least one of said at least one non-backward compatible carrier with one of said at least one backward compatible carrier. The wireless device transmits channel state information of one of said at least one non-backward compatible carrier on an uplink carrier of one of said at least one backward compatible carrier.