A method comprising: providing at least first and second operationally adjacent base stations, each base station providing (72; 71) at least one cell (F2a, F2b) in respect of a first carrier and at least one cell (F1a, F1b) in respect of a second carrier; wherein for the first carrier, the cell area (F2b) provided by the first base station is substantially larger than the cell area (F2a) provided by the second base station and the cells (F2a, F2b) in respect of the first carrier overlap providing a first carrier handover area; the method characterised by: for the second carrier, the cell area (F1b) provided by the first base station is substantially smaller than the cell area (F1a) provided by said second base station; wherein the cells (F1a, F1b, F2a, F2b) of the first and second carrier are arranged such that: the cells (F1a, F1b) in respect of the second carrier overlap providing a second handover area; and the cell (F2b) provided by the first base station in respect of the first carrier and the cell (F1a) provided by the second base station in respect of the second carrier overlap providing a third handover area which is large in size compared to each of the first and second handover areas. providing at least first and second operationally adjacent base stations, each base station providing (72; 71) at least one cell (F2a, F2b) in respect of a first carrier and at least one cell (F1a, F1b) in respect of a second carrier; wherein for the first carrier, the cell area (F2b) provided by the first base station is substantially larger than the cell area (F2a) provided by the second base station and the cells (F2a, F2b) in respect of the first carrier overlap providing a first carrier handover area; the method characterised by: for the second carrier, the cell area (F1b) provided by the first base station is substantially smaller than the cell area (F1a) provided by said second base station; wherein the cells (F1a, F1b, F2a, F2b) of the first and second carrier are arranged such that: the cells (F1a, F1b) in respect of the second carrier overlap providing a second handover area; and the cell (F2b) provided by the first base station in respect of the first carrier and the cell (F1a) provided by the second base station in respect of the second carrier overlap providing a third handover area which is large in size compared to each of the first and second handover areas. for the second carrier, the cell area (F1b) provided by the first base station is substantially smaller than the cell area (F1a) provided by said second base station; wherein the cells (F1a, F1b, F2a, F2b) of the first and second carrier are arranged such that: the cells (F1a, F1b) in respect of the second carrier overlap providing a second handover area; and the cell (F2b) provided by the first base station in respect of the first carrier and the cell (F1a) provided by the second base station in respect of the second carrier overlap providing a third handover area which is large in size compared to each of the first and second handover areas. the cells (F1a, F1b) in respect of the second carrier overlap providing a second handover area; and the cell (F2b) provided by the first base station in respect of the first carrier and the cell (F1a) provided by the second base station in respect of the second carrier overlap providing a third handover area which is large in size compared to each of the first and second handover areas.