A method for performing communication by a user equipment, UE , in a wireless communication system, the method comprising: receiving, from a small cell, cell state information; and communicating with the small cell based on the cell state information, wherein a macro cell and the small cell are aggregated and provided to the UE, wherein a base station for the small cell is different from a base station for the macro cell, wherein the macro cell is a primary cell and the small cell is a secondary cell, wherein the a physical uplink control channel, PUCCH, is transmitted on the small cell, wherein both the macro cell and the small cell respectively perform scheduling, wherein the cell state information includes cell change information, time related information, target cell related information, PUCCH cell information and hybrid automatic repeat request, HARQ, process related information, wherein cell state change information indicates that the small cell changes from an OFF state to an ON state or from the ON state to the OFF state, wherein the time related information indicates a time when a state change of the small cell applies and a time period when the state change is to apply, wherein the time related information further indicates a handover period and a period when a delay request signal is to be transmitted, wherein the target cell related information indicates a carrier index or an identifier of a target cell to which the UE is to hand over, wherein the PUCCH cell information indicates a cell on which the PUCCH is transmitted, wherein the HARQ process related information is information for instructing to take over a HARQ process that has been performed for the small cell whose state is to be changed from the ON state to the OFF state, wherein the cell state information is transmitted through downlink control information, DCI, and wherein the DCI is masked with a radio network temporary identifier, RNTI, for the purpose of delivering the cell state information. receiving, from a small cell, cell state information; and communicating with the small cell based on the cell state information, wherein a macro cell and the small cell are aggregated and provided to the UE, wherein a base station for the small cell is different from a base station for the macro cell, wherein the macro cell is a primary cell and the small cell is a secondary cell, wherein the a physical uplink control channel, PUCCH, is transmitted on the small cell, wherein both the macro cell and the small cell respectively perform scheduling, wherein the cell state information includes cell change information, time related information, target cell related information, PUCCH cell information and hybrid automatic repeat request, HARQ, process related information, wherein cell state change information indicates that the small cell changes from an OFF state to an ON state or from the ON state to the OFF state, wherein the time related information indicates a time when a state change of the small cell applies and a time period when the state change is to apply, wherein the time related information further indicates a handover period and a period when a delay request signal is to be transmitted, wherein the target cell related information indicates a carrier index or an identifier of a target cell to which the UE is to hand over, wherein the PUCCH cell information indicates a cell on which the PUCCH is transmitted, wherein the HARQ process related information is information for instructing to take over a HARQ process that has been performed for the small cell whose state is to be changed from the ON state to the OFF state, wherein the cell state information is transmitted through downlink control information, DCI, and wherein the DCI is masked with a radio network temporary identifier, RNTI, for the purpose of delivering the cell state information. <EOS>