Channel state information reporting on licensed and unlicensed carriers

A non-transitory computer-readable medium storing instructions that when executed by a mobile station cause the mobile station to report channel state information, CSI, to a base station in a mobile communication system in which a plurality of downlink component carriers and at least one uplink component carrier are configured for communication between the base station and the mobile station, comprising:

• receiving from the base station a trigger message that triggers the reporting of channel state information for at least one of the plurality of downlink component carriers, the trigger message being received in a subframe nTrigger;
• and
• reporting to the base station, the triggered channel state information for the at least one of the plurality of downlink component carriers based on reference signals, RS, present on the at least one of the plurality of downlink component carriers, in a subframe nReport later than nTrigger,
• wherein the received trigger message indicates that the reference signals, RS, on the basis of which the channel state information is to be reported, are present in a subframe nRS on the at least one of the plurality of downlink component carriers, where nTrigger≦nRS<nReport.