Method and apparatus for transmitting/receiving data using plurality of carriers in mobile communication system

1. A method by a terminal in a wireless communication system, comprising:

receiving, from a first base station with which a first cell group is associated, a control message for configuring a second cell group associated with a second base station, wherein the control message includes first information on a bearer type;

identifying whether the bearer type is a first bearer type, wherein a bearer is associated with both the first base station and the second base station in the first bearer type;

if the bearer type is the first bearer type, obtaining second information in the control message, wherein the second information indicates whether uplink transmission is performed via the second cell group associated with the second base station for the first bearer type;

if the second information indicates that the uplink transmission is performed via the second cell group associated with the second base station for the first bearer type, transmitting uplink data via the second cell group associated with the second base station, and

transmitting uplink data via the second cell group associated with the second base station if the bearer type is a second bearer type, wherein a bearer is related to the second cell group associated with the second base station in the second bearer type.

2. The method of claim 1 , wherein the first bearer type corresponds to a multi-logical channel (LCH)-radio bearer (RB) and the second bearer type corresponds to a single-logical channel (LCH)-Secondary Cell Group (SCG)-radio bearer (RB).

3. The method of claim 1 , further comprises:

if the second information does not indicate that the uplink transmission is performed via the second cell group associated with the second base station for the first bearer type, transmitting uplink data via the first cell group.

4. A method by a first base station with which a first cell group is associated in a wireless communication system, comprising:

determining, with a second base station, to configure a second cell group associated with the second base station; and

transmitting, to a terminal, a control message for configuring the second cell group associated with the second base station,

wherein the control message includes first information on a bearer type,

wherein if the bearer type is a first bearer type, the control message further includes second information indicating whether uplink transmission is performed via the second cell group associated with the second base station for the first bearer type, a bearer being associated with both the first base station and the second base station in the first bearer type, and

wherein transmission and reception of data via the first cell group associated with the first base station is omitted if the bearer type is a second bearer type, wherein a bearer is related to the second cell group associated with the second base station in the second bearer type.

5. The method of claim 4 , wherein the first bearer type corresponds to a multi-logical channel (LCH)-radio bearer (RB) and the second bearer type corresponds to a single-logical channel (LCH)-Secondary Cell Group (SCG)-radio bearer (RB).

6. The method of claim 4 , further comprising:

receiving uplink data via the first cell group if the bearer type is the first bearer type and the second information does not indicate that the uplink transmission is performed via the second cell group associated with the second base station for the first bearer type.

7. A method by a second base station with which a second cell group is associated in a wireless communication system, comprising:

determining, with a first base station, to configure the second cell group; and

receiving uplink data from a terminal via the second cell group,

wherein a control message, which is transmitted from the first base station associated with a first cell group to the terminal, for configuring the second cell group includes first information on a bearer type,

wherein, if the bearer type is a first bearer type, the control message further includes second information indicating whether uplink transmission is performed via the second cell group associated with the second base station for the first bearer type, a bearer being associated with both the first base station and the second base station in the first bearer type,

wherein, if the second information indicates that the uplink transmission is performed via the second cell group associated with the second base station for the first bearer type, uplink data is transmitted from the terminal via the second cell group associated with the second base station,

wherein uplink data is transmitted from the terminal via the second cell group associated with the second base station if the bearer type is a second bearer type, and

wherein a bearer is related to the second cell group associated with the second base station in the second bearer type.

8. The method of claim 7 ,

wherein the first bearer type corresponds to a multi-logical channel (LCH)-radio bearer (RB) and the second bearer type corresponds to a single-logical channel (LCH)-Secondary Cell Group (SCG)-radio bearer (RB).

9. A terminal comprising:

a transceiver configured to transmit and receive signals with a first base station and a second base station; and

a control unit configured to:

receive from the first base station with which a first cell group is associated, a control message for configuring a second cell group associated with the second base station, wherein the control message includes first information on a bearer type;

identify whether the bearer type is a first bearer type, wherein a bearer is associated with both the first base station and the second base station in the first bearer type;

if second information indicates that uplink transmission is performed via the second cell group associated with the second base station for the first bearer type, transmit uplink data via the second cell group associated with the second base station; and

transmit uplink data via the second cell group associated with the second base station if the bearer type is a second bearer type, wherein a bearer is related to the second cell group associated with the second base station in the second bearer type.

10. The terminal of claim 9 , wherein the first bearer type corresponds to a multi-logical channel (LCH)-radio bearer (RB) and the second bearer type corresponds to a single-logical channel (LCH)-Secondary Cell Group (SCG)-radio bearer (RB).

11. The terminal of claim 9 , wherein the control unit is further configured to:

if the second information does not indicate that the uplink transmission is performed via the second cell group associated with the second base station for the first bearer type, transmit uplink data via the first cell group.

12. A first base station with which a first cell group is associated, the first base station comprising:

a transceiver configured to transmit and receive signals with a terminal and a second base station; and

a control unit configured to:

determine, with the second base station, whether to configure a second cell group associated with the second base station; and

transmit, to the terminal, a control message for configuring the second cell group associated with the second base station,

wherein the control message includes first information on a bearer type,

wherein if the bearer type is a first bearer type, the control message further includes second information indicating whether uplink transmission is performed via the second cell group associated with the second base station for the first bearer type, a bearer being associated with both the first base station and the second base station in the first bearer type, and

wherein transmission and reception of data via the first cell group associated with the first base station is omitted if the bearer type is a second bearer type, wherein a bearer is related to the second cell group associated with the second base station in the second bearer type.

13. The first base station of claim 12 , wherein the first bearer type corresponds to a multi-logical channel (LCH)-radio bearer (RB) and the second bearer type corresponds to a single-logical channel (LCH)-Secondary Cell Group (SCG)-radio bearer (RB).

14. The first base station of claim 12 , wherein the control unit is further configured to receive uplink data via the first cell group if the bearer type is the first bearer type and the second information does not indicate that the uplink transmission is performed via the second cell group associated with the second base station for the first bearer type.

15. A second base station with which a second cell group is associated, the second base station comprising:

a transceiver configured to transmit and receive signals with a terminal and a first base station; and

a control unit is configured to:

determine, with the first base station, whether to configure the second cell group; and

receive uplink data from the terminal via the second cell group,

wherein a control message, which is transmitted from the first base station associated with a first cell group to the terminal, for configuring the second cell group includes first information on a bearer type,

wherein, if the bearer type is a first bearer type, the control message further includes second information indicating whether uplink transmission is performed via the second cell group associated with the second base station for the first bearer type, a bearer being associated with both the second base station and the first base station in the first bearer type,

wherein, if the second information indicates that the uplink transmission is performed via the second cell group associated with the second base station for the first bearer type, uplink data is transmitted from the terminal via the second cell group associated with the second base station,

wherein uplink data is transmitted from the terminal via the second cell group associated with the second base station if the bearer type is a second bearer type, and

wherein a bearer is related to the second cell group in the second bearer type.

16. The second base station of claim 15 ,

wherein the first bearer type corresponds to a multi-logical channel (LCH)-radio bearer (RB) and the second bearer type corresponds to a single-logical channel (LCH)-Secondary Cell Group (SCG)-radio bearer (RB).