Communication apparatus for a cellular communication system, the communication apparatus comprising: means for operating a first cell using a first component carrier and a second cell using a second component carrier, wherein: reference signals of a first type are provided in a control region and in a data region of sub-frames communicated using the first component carrier; the reference signals of the first type are not provided in sub-frames communicated using the second component carrier; and reference signals of a second type are provided in a data region but are not provided in a control region of sub-frames communicated using the second component carrier; means for communicating with a mobile communication device using the first component carrier; means for communicating with the mobile communication device using the second component carrier; means for receiving, from the mobile communication device, results of measurements performed on the reference signals of the first type for the first component carrier and results of measurements performed on the reference signals of the second type for the second component carrier; characterized by further comprising means for determining from the results of the measurements performed on the reference signals of the second type, whether or not said mobile communication device is within an area covered by said second cell; and means for transmitting to the mobile communication device, in dependence on whether or not said mobile communication device is within the area covered by said second cell, information for allowing said mobile communication device to communicate using said second component carrier in said second cell. means for operating a first cell using a first component carrier and a second cell using a second component carrier, wherein: reference signals of a first type are provided in a control region and in a data region of sub-frames communicated using the first component carrier; the reference signals of the first type are not provided in sub-frames communicated using the second component carrier; and reference signals of a second type are provided in a data region but are not provided in a control region of sub-frames communicated using the second component carrier; reference signals of a first type are provided in a control region and in a data region of sub-frames communicated using the first component carrier; the reference signals of the first type are not provided in sub-frames communicated using the second component carrier; and reference signals of a second type are provided in a data region but are not provided in a control region of sub-frames communicated using the second component carrier; means for communicating with a mobile communication device using the first component carrier; means for communicating with the mobile communication device using the second component carrier; means for receiving, from the mobile communication device, results of measurements performed on the reference signals of the first type for the first component carrier and results of measurements performed on the reference signals of the second type for the second component carrier; characterized by further comprising means for determining from the results of the measurements performed on the reference signals of the second type, whether or not said mobile communication device is within an area covered by said second cell; and means for transmitting to the mobile communication device, in dependence on whether or not said mobile communication device is within the area covered by said second cell, information for allowing said mobile communication device to communicate using said second component carrier in said second cell.