A method for setting up a dual-connectivity during a handover procedure by a target base station, the method comprising: receiving , from a source base station, a handover request message; determining whether to add a secondary base station for setting up the dual-connectivity for a user equipment, UE, in response to the handover request message; transmitting , to the secondary base station, a secondary base station addition request message according to the determination; receiving , from the secondary base station, a secondary base station addition request acknowledge message corresponding to the secondary base station addition request message; determining a data forwarding mode corresponding to an indirect data forwarding from the source base station via the target master base station to the secondary base station or to a direct data forwarding from the source base station to the secondary base station; transmitting , to the source base station, a handover request acknowledge message including information related to the indirect data forwarding or information related to the direct data forwarding in response to the determination of adding the secondary base station, wherein the information related to the indirect data forwarding includes a tunnel endpoint identifier, TEID, and a transport layer address allocated by the target base station and wherein the information related to the direct data forwarding includes a TEID and a transport layer address received from the secondary base station; in case the indirect data forwarding mode is determined, receiving , from the source base station, data forwarded based on the information related to the indirect data forwarding; receiving , from the UE, a radio resource control, RRC, reconfiguration complete message; and transmitting , to the secondary base station, a secondary base station reconfiguration complete message in response to the RRC reconfiguration complete message. receiving , from a source base station, a handover request message; determining whether to add a secondary base station for setting up the dual-connectivity for a user equipment, UE, in response to the handover request message; transmitting , to the secondary base station, a secondary base station addition request message according to the determination; receiving , from the secondary base station, a secondary base station addition request acknowledge message corresponding to the secondary base station addition request message; determining a data forwarding mode corresponding to an indirect data forwarding from the source base station via the target master base station to the secondary base station or to a direct data forwarding from the source base station to the secondary base station; transmitting , to the source base station, a handover request acknowledge message including information related to the indirect data forwarding or information related to the direct data forwarding in response to the determination of adding the secondary base station, wherein the information related to the indirect data forwarding includes a tunnel endpoint identifier, TEID, and a transport layer address allocated by the target base station and wherein the information related to the direct data forwarding includes a TEID and a transport layer address received from the secondary base station; in case the indirect data forwarding mode is determined, receiving , from the source base station, data forwarded based on the information related to the indirect data forwarding; receiving , from the UE, a radio resource control, RRC, reconfiguration complete message; and transmitting , to the secondary base station, a secondary base station reconfiguration complete message in response to the RRC reconfiguration complete message. <EOS>