Disclosed are a transmission method and a base station comprising: user equipment confirming a handover to be performed; transmitting to a macro cell a data forwarding request message for requesting forwarding of downlink data of a small cell to the user equipment, when the user equipment can establish an X2 or S1 interface with the macro cell to perform the handover; receiving from the macro cell a data forwarding response message for indicating establishment of a wireless bearer with the macro cell; and transmitting the downlink data to the macro cell through the established wireless bearer, based on the data forwarding response message.