Method and apparatus for switching connection in wireless communication system

1. A method for switching from a device-to-device (D2D) connection to a base station-to-device (B2D) connection, by a first device, in a wireless communication system, the method comprising:

transmitting first data traffic to a second device through the D2D connection, wherein the first device is in a radio resource control (RRC) idle state, wherein the second device is in a RRC connected state;

receiving a B2D switch request message from a base station, wherein the B2D switch request message includes information on the second device, a switch unit, D2D connection/link identifier(s) of the second device, an enhanced packet system (EPS) bearer identity, a data radio bearer (DRB) identity, a radio link control (RLC) configuration, a logical channel identity, and a B2D switch time identifying when the first device is to switch from the D2D connection to a B2D connection;

transmitting a B2D switch response message, to the base station, as a response to the B2D switch request message;

releasing the D2D connection, wherein, according to the switch unit, the D2D connection is released per flow, per bearer, or for all flows; and

transmitting second data traffic to the base station, which delivers the second data traffic to the second device.

2. The method of claim 1 , further comprising:

receiving a paging message from the base station; and

performing an RRC connection establishment procedure with the base station.

3. The method of claim 1 , further comprising performing an RRC connection reconfiguration procedure with the base station.