In a data transmission process of a heterogeneous LWA network, the base station device receives a series of data packets and a signal intensity information. A communication address of each of the series of data packet is directed to a specified user mobile device, and the signal intensity information indicates an intensity of a signal transmitted between the specified user mobile device and a wireless network access point device in communication with the base station device and the specified user mobile device. If the signal intensity information complies with a first specific condition and a status of data transmission associated with the user mobile device complies with a second specific condition, partial data packets are assigned to be transferred to the user mobile device by the wireless network access point device, and partial data packets are assigned to be transferred to the user mobile device by the base station device.