A method for data transmission in a base station of a communication network with a user equipment dominated by the base station, wherein the communication network comprises a cellular network and an assistant wireless network dedicated to the cellular network; the assistant wireless network comprises at least one assistant wireless network access node; the assistant network uses unlicensed frequency spectrum resources; and the at least one assistant wireless network access node is connected to the base station via a wired or wireless link, wherein the method comprises the following steps: a. maintaining a first control channel in the cellular network between the base station and the user equipment, wherein the first control channel is used for exchanging with the user equipment control signalling of a data channel in the cellular network; b. exchanging control signalling of an emulation data channel with the user equipment; wherein the control signalling of the emulation data channel comprises - establishing and releasing information of the emulation data channel, d. establishing the emulation data channel that connects the base station to the user equipment via the assistant wireless network and the wired or wireless link between the assistant wireless network access node and the base station; and e. at least receiving data from or sending data to the user equipment via the emulation data channel; wherein the exchanging further comprises: establishing a second control channel for exchanging with the user equipment the control signalling of the emulation data channel, wherein the second control channel connects the base station to the user equipment via the assistant wireless network and the wired or wireless link between the assistant wireless network access node and the base station; and wherein the method further comprises, between the exchanging and the establishing the emulation data channel: based on a first predetermined condition, selecting the data channel in the cellular network and/or the emulation data channel to receive data from or send data to the user equipment, and sending to the user equipment an instruction for indicating a selection result, wherein the first predetermined condition comprises at least one of the following items: load condition between the data channel in the cellular network and the emulation data channel; a data type of a traffic; or power consumption of the user equipment. a. maintaining a first control channel in the cellular network between the base station and the user equipment, wherein the first control channel is used for exchanging with the user equipment control signalling of a data channel in the cellular network; b. exchanging control signalling of an emulation data channel with the user equipment; wherein the control signalling of the emulation data channel comprises - establishing and releasing information of the emulation data channel, - establishing and releasing information of the emulation data channel, d. establishing the emulation data channel that connects the base station to the user equipment via the assistant wireless network and the wired or wireless link between the assistant wireless network access node and the base station; and e. at least receiving data from or sending data to the user equipment via the emulation data channel; establishing a second control channel for exchanging with the user equipment the control signalling of the emulation data channel, wherein the second control channel connects the base station to the user equipment via the assistant wireless network and the wired or wireless link between the assistant wireless network access node and the base station; and wherein the method further comprises, between the exchanging and the establishing the emulation data channel: based on a first predetermined condition, selecting the data channel in the cellular network and/or the emulation data channel to receive data from or send data to the user equipment, and sending to the user equipment an instruction for indicating a selection result, wherein the first predetermined condition comprises at least one of the following items: load condition between the data channel in the cellular network and the emulation data channel; a data type of a traffic; or power consumption of the user equipment. based on a first predetermined condition, selecting the data channel in the cellular network and/or the emulation data channel to receive data from or send data to the user equipment, and sending to the user equipment an instruction for indicating a selection result, wherein the first predetermined condition comprises at least one of the following items: load condition between the data channel in the cellular network and the emulation data channel; a data type of a traffic; or power consumption of the user equipment. load condition between the data channel in the cellular network and the emulation data channel; a data type of a traffic; or power consumption of the user equipment.