A wireless communications system comprising: a master base station (110; 321) configured to control a first wireless communication using LTE-A; a secondary base station configured to have the function of both the first wireless communication and a second wireless communication using WLAN; and a mobile station (120; 311) configured to perform data transmission and reception, of one or more EPS bearers, with the master base station (110; 321) directly via the first wireless communication and concurrently with the secondary base station via the second wireless communication, wherein the master base station (110; 321) is configured to process the data by a convergence layer, wherein a sequence number is added, wherein the convergence layer is a layer where optionally ciphering and header compression is performed; the master base station (110; 321) is further configured to split the data of one or more EPS bearers in the convergence layer and to transfer some of the data from each EPS bearer directly to the mobile station (120; 311) via the first wireless communication and the rest of the data from each EPS bearer to the secondary base station, through a different GTP tunnel for each EPS bearer; the secondary base station is further configured to apply GRE tunneling for each EPS bearer, to the received data, to set an available MAC address of the mobile station (120; 311) as a destination address and to transmit the data that is converted to MAC Ethernet frames to the mobile station (120; 311), and the mobile station (120; 311) is configured to identify the EPS bearer corresponding to the data using the GRE tunneling, wherein the mobile station (120; 311) is configured to perform, according to the sequence number, sequence control of the data transmitted from the master base station (110; 321) via the first wireless communication and data transmitted from the secondary base station via the second wireless communication. a master base station (110; 321) configured to control a first wireless communication using LTE-A; a secondary base station configured to have the function of both the first wireless communication and a second wireless communication using WLAN; and a mobile station (120; 311) configured to perform data transmission and reception, of one or more EPS bearers, with the master base station (110; 321) directly via the first wireless communication and concurrently with the secondary base station via the second wireless communication, wherein the master base station (110; 321) is configured to process the data by a convergence layer, wherein a sequence number is added, wherein the convergence layer is a layer where optionally ciphering and header compression is performed; the master base station (110; 321) is further configured to split the data of one or more EPS bearers in the convergence layer and to transfer some of the data from each EPS bearer directly to the mobile station (120; 311) via the first wireless communication and the rest of the data from each EPS bearer to the secondary base station, through a different GTP tunnel for each EPS bearer; the secondary base station is further configured to apply GRE tunneling for each EPS bearer, to the received data, to set an available MAC address of the mobile station (120; 311) as a destination address and to transmit the data that is converted to MAC Ethernet frames to the mobile station (120; 311), and the mobile station (120; 311) is configured to identify the EPS bearer corresponding to the data using the GRE tunneling, wherein the mobile station (120; 311) is configured to perform, according to the sequence number, sequence control of the data transmitted from the master base station (110; 321) via the first wireless communication and data transmitted from the secondary base station via the second wireless communication.