A mobile communications system for communicating data to/from mobile units, including: one or more base stations to communicate data to/from the mobile units; first and second groups of one or more mobile units to communicate with the one or more base stations via respective first and second carriers. The base stations can provide, on the first carrier, common information for at least one mobile unit in the first group and for at least one mobile unit in the second group. The base stations can provide allocation information in the first and second carriers, the allocation information including an indication of the location of the common information within the first carrier. At least one mobile unit in the second group is configured, 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.