Method and apparatus for transmitting and receiving data in wireless communication system

1. A method performed by a centralized unit (CU)-user plane (UP) of a base station in a wireless communication system, the method comprising:

receiving, from a CU-control plane (CP) of the base station, a bearer context modification request message,

wherein the bearer context modification request message comprises information associated with a request for a packet data convergence protocol (PDCP) sequence number (SN) status; and

transmitting, based on the bearer context modification request message, a bearer context modification response message to the CU-CP of the base station,

wherein the bearer context modification response message comprises information associated with the PDCP SN status and information indicating at least one quality of service (QoS) flow, of which a service data adaptation protocol (SDAP) end marker is not received by the CU-UP of the base station.

2. The method of claim 1 , wherein the information associated with the request for the PDCP SN status comprises information used by the CU-CP of the base station to request provision of the PDCP SN status from the CU-UP of the base station.

3. The method of claim 1 , wherein the information indicating the at least one QoS flow, of which the SDAP end marker is not received comprises information indicating the at least one QoS flow, of which the SDAP end marker is not received by the CU-UP of the base station, in case that remapping of a QoS flow to a data radio bearer (DRB) is performed by the CU-CP of the base station.

4. The method of claim 1 , wherein the information indicating the at least one QoS flow, of which the SDAP end marker is not received is included in the bearer context modification response message in response to a handover being performed when the CU-CP of the base station performs remapping of a QoS flow to a data radio bearer (DRB).

5. The method of claim 1 , further comprising:

transmitting a bearer context modification required message to the CU-CP of the base station, wherein the bearer context modification required message comprises an identifier of a QoS flow, of which the SDAP end marker is received by the CU-UP of the CU of the base station; and

receiving, from the CU-CP of the base station, based on the bearer context modification required message, a bearer context modification confirm message.

6. A centralized unit (CU)-user plane (UP) of a base station in a wireless communication system, the CU-UP comprising:

a transceiver; and

at least one processor coupled with the transceiver and configured to:

receive, from a CU-control plane (CP) of the base station, a bearer context modification request message,

wherein the bearer context modification request message comprises information associated with a request for a packet data convergence protocol (PDCP) sequence number (SN) status, and

transmit, based on the bearer context modification request message, a bearer context modification response message to the CU-CP of the base station,

wherein the bearer context modification response message comprises information associated with the PDCP SN status and information indicating at least one quality of service (QoS) flow, of which a service data adaptation protocol (SDAP) end marker is not received by the CU-UP of the base station.

7. The CU-UP of claim 6 , wherein the information associated with the request for the PDCP SN status comprises information used by the CU-CP of the base station to request provision of the PDCP SN status from the CU-UP of the base station.

8. The CU-UP of claim 6 , wherein the information indicating the at least one QoS flow, of which the SDAP end marker is not received comprises information indicating the at least one QoS flow, of which the SDAP end marker is not received by the CU-UP of the base station, in case that remapping of a QoS flow to a data radio bearer (DRB) is performed by the CU-CP of the base station.

9. The CU-UP of claim 6 , wherein the information indicating the at least one QoS flow, of which the SDAP end marker is not received is included in the bearer context modification response message in response to a handover being performed when the CU-CP of the base station performs remapping of a QoS flow to a data radio bearer (DRB).

10. The CU-UP of claim 6 , wherein the at least one processor is further configured to:

transmit a bearer context modification required message to the CU-CP of the base station, wherein the bearer context modification required message comprises an identifier of a QoS flow, of which the SDAP end marker is received by the CU-UP of the CU of the base station, and

receive, from the CU-CP of the base station, based on the bearer context modification required message, a bearer context modification confirm message.

11. A method performed by a centralized unit (CU)-control plane (CP) of a base station in a wireless communication system, the method comprising:

transmitting a bearer context modification request message to a CU-user plane (UP) of the base station,

wherein the bearer context modification request message comprises information associated with a request for a packet data convergence protocol (PDCP) sequence number (SN) status; and

receiving, based on the bearer context modification request message, a bearer context modification response message from the CU-UP of the base station,

wherein the bearer context modification response message comprises information associated with the PDCP SN status and information indicating at least one quality of service (QoS) flow, of which a service data adaptation protocol (SDAP) end marker is not received by the CU-UP of the base station.

12. The method of claim 11 , wherein the information associated with the request for the PDCP SN status comprises information used by the CU-CP of the base station to request provision of the PDCP SN status from the CU-UP of the base station.

13. The method of claim 11 , wherein the information indicating the at least one QoS flow, of which the SDAP end marker is not received comprises information indicating the at least one QoS flow, of which the SDAP end marker is not received by the CU-UP of the base station, in case that remapping of a QoS flow to a data radio bearer (DRB) is performed by the CU-CP of the base station.

14. The method of claim 11 , wherein the information indicating the at least one QoS flow, of which the SDAP end marker is not received is included in the bearer context modification response message in response to a handover being performed when the CU-CP of the base station performs remapping of a QoS flow to a data radio bearer (DRB).

15. The method of claim 11 further comprising:

receiving a bearer context modification required message from the CU-UP of the base station, wherein the bearer context modification required message comprises an identifier of a QoS flow, of which the SDAP end marker is received by the CU-UP of the base station; and

transmitting, based on the bearer context modification required message, a bearer context modification confirm message to the CU-UP of the base station.

16. A centralized unit (CU)-control plane (CP) of a base station in a wireless communication system, the CU-CP comprising:

a transceiver; and

at least one processor coupled with the transceiver and configured to:

transmit a bearer context modification request message to a CU-user plane (UP),

wherein the bearer context modification request message comprises information associated with a request for a packet data convergence protocol (PDCP) sequence number (SN) status, and

receive, based on the bearer context modification request message, a bearer context modification response message from the CU-UP of the base station,

wherein the bearer context modification response message comprises information associated with the PDCP SN status and information indicating at least one quality of service (QoS) flow, of which a service data adaptation protocol (SDAP) end marker is not received by the CU-UP of the base station.

17. The CU-CP of claim 16 , wherein the information associated with the request for the PDCP SN status comprises information used by the CU-CP of the base station to request provision of the PDCP SN status from the CU-UP of the base station.

18. The CU-CP of claim 16 , wherein the information indicating the at least one QoS flow, of which the SDAP end marker is not received comprises information indicating the at least one QoS flow, of which the SDAP end marker is not received by the CU-UP of the base station, in case that remapping of a QoS flow to a data radio bearer (DRB) is performed by the CU-CP of the base station.

19. The CU-CP of claim 16 , wherein the information indicating the at least one QoS flow, of which the SDAP end marker is not received is included in the bearer context modification response message in response to a handover being performed when the CU-CP of the base station performs remapping of a QoS flow to a data radio bearer (DRB).

20. The CU-CP of claim 16 , wherein the at least one processor is further configured to:

receive a bearer context modification required message from the CU-UP of the base station, wherein the bearer context modification required message comprises an identifier of a QoS flow, of which the SDAP end marker is received by the CU-UP of the base station, and

transmit, based on the bearer context modification required message, a bearer context modification confirm message to the CU-UP of the base station.