A method for communicating Downlink Control Information (DCI) in an asymmetric multicarrier communication network environment, the method comprising: determining a carrier type corresponding to DCI to be transmitted to a mobile station from a plurality of carrier types, encoding the DCI in a DCI format, wherein the DCI format comprises a set of fields corresponding to the determined carrier type, and transmitting the DCI encoded in the DCI format to the mobile station through a downlink control channel on a primary carrier, wherein the DCI format comprises a carrier index field indicating type of the fields in the DCI format encoding the DCI and the carrier type corresponding to the encoded DCI.