A mobile communications system for communicating data to and/or from mobile units, the system comprising: one or more base stations arranged to communicate data to or from the mobile units via a wireless access interface within one or more frequency bands, and one or more of the base stations is arranged to provide a plurality of logically separate carriers for transmitting data to mobile units, wherein each of the logically separate carriers comprises physical communications resources within the one or more frequency bands of the wireless access interface; a first group of one or more mobile units arranged to communicate with the one or more base stations via at least a first carrier of the plurality of carriers; a second group of one or more mobile units arranged to communicate with the one or more base stations via at least a second carrier of the plurality of carriers; wherein the one or more base stations are operable to provide common information on the first carrier, the common information being for at least one mobile unit in the first group and for at least one mobile unit in the second group; the one or more base stations are operable to provide allocation information in the first carrier, the allocation information comprising an indication of the location of the common information within the first carrier; the one or more base stations are further operable to provide allocation information in the second carrier, the allocation information comprising an indication of the location of the common information within the first carrier; and at least one mobile unit in the second group is arranged, upon reception of the allocation information in the second carrier, to access the common information provided by the one or more base stations in the first carrier. one or more base stations arranged to communicate data to or from the mobile units via a wireless access interface within one or more frequency bands, and one or more of the base stations is arranged to provide a plurality of logically separate carriers for transmitting data to mobile units, wherein each of the logically separate carriers comprises physical communications resources within the one or more frequency bands of the wireless access interface; a first group of one or more mobile units arranged to communicate with the one or more base stations via at least a first carrier of the plurality of carriers; a second group of one or more mobile units arranged to communicate with the one or more base stations via at least a second carrier of the plurality of carriers; wherein the one or more base stations are operable to provide common information on the first carrier, the common information being for at least one mobile unit in the first group and for at least one mobile unit in the second group; the one or more base stations are operable to provide allocation information in the first carrier, the allocation information comprising an indication of the location of the common information within the first carrier; the one or more base stations are further operable to provide allocation information in the second carrier, the allocation information comprising an indication of the location of the common information within the first carrier; and at least one mobile unit in the second group is arranged, upon reception of the allocation information in the second carrier, to access the common information provided by the one or more base stations in the first carrier.