Method and apparatus for driving PDCP entity during DAPS handover in next-generation wireless communication system
The disclosure relates to a communication method and system for converging a 5 th -Generation (5G) communication system for supporting higher data rates beyond a 4 th -Generation (4G) system with a technology for Internet of Things (IoT). The disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The disclosure provides a method and an apparatus for operating a PDCP entity during a handover having no transmission/reception interruption.
1. A method performed by a terminal in a wireless communication system, the method comprising:
receiving, from a source base station, a first radio resource control (RRC) message configuring a data radio bearer (DRB) associated with a dual active protocol stack (DAPS) handover, the first RRC message including information on status report required, and the information indicating that the DRB is configured to transmit a packet data convergence protocol (PDCP) status report in uplink;
performing, with a target base station, a random access procedure for a DAPS handover based on the first RRC message;
in case that a successful completion of the of the random access procedure is identified by a medium access control (MAC) entity, indicating the successful completion of the random access procedure to an upper layer;
in case that the successful completion of the random access procedure is identified by the upper layer, requesting uplink data switching for the DRB to a PDCP entity;
in case that request of the uplink data switching from the upper layer is identified by the PDCP entity,
triggering a first PDCP status report for the DRB; and
transmitting, to the target base station, the triggered first PDCP status report.
2. The method of claim 1 , wherein the DRB associated with the first PDCP status report is at least one of acknowledged mode (AM) DRB or unacknowledged mode (UM) DRB.
3. The method of claim 1 , further comprising:
receiving, from the target base station, a second RRC message including an indication to release a connection with the source base station;
triggering a second PDCP status report for the DRB based on the indication; and
transmitting, to the target base station, the triggered second PDCP status report.
4. A method performed by a base station in a wireless communication system, the method comprising:
performing, with a terminal, a random access procedure for a dual active protocol stack (DAPS) handover by using a data radio bearer (DRB) associated with the DAPS handover;
in case that the random access procedure is successfully completed, receiving, from the terminal, a first PDCP status report for the DRB;
transmitting, to the terminal, a radio resource control (RRC) message including an indication to release a connection with a source base station; and
receiving, from the terminal, a second PDCP status report for the DRB.
5. The method of claim 4 , wherein the DRB associated with the first PDCP status report is at least one of acknowledged mode (AM) DRB or unacknowledged mode (UM) DRB.
6. The method of claim 4 ,
wherein the DRB associated with the second PDCP status report is an acknowledged mode (AM) DRB.
7. A terminal in a wireless communication system, the terminal comprising:
a transceiver configured to transmit and receive a signal; and
a controller configured to:
receive, from a source base station, a first radio resource control (RRC) message configuring a data radio bearer (DRB) associated with a dual active protocol stack (DAPS) handover, the first RRC message including information on status report required, and the information indicating that the DRB is configured to transmit a packet data convergence protocol (PDCP) status report in uplink,
perform, with a target base station, a random access procedure for a DAPS handover based on the first RRC message,
in case that a successful completion of the of the random access procedure is identified by a medium access control (MAC) entity, indicate the successful completion of the random access procedure to an upper layer,
in case that the successful completion of the random access procedure is identified by the upper layer, request uplink data switching for the DRB to a PDCP entity,
in case that request of the uplink data switching from the upper layer is identified by the PDCP entity
trigger a first PDCP status report for the DRB, and
transmit, to the target base station, the triggered first PDCP status report.
8. The terminal of claim 7 , wherein the DRB associated with the first PDCP status report is at least one of acknowledged mode (AM) DRB or unacknowledged mode (UM) DRB.
9. The terminal of claim 7 , wherein the controller is further configured to:
receive, from the target base station, a second RRC message including an indication to release a connection with the source base station;
trigger a second PDCP status report for the DRB based on the indication; and
transmit, to the target base station, the triggered second PDCP status report.
10. A base station in a wireless communication system, the base station comprising:
a transceiver configured to transmit and receive a signal; and
a controller configured to:
perform, with a terminal, a random access procedure for a dual active protocol stack (DAPS) handover by using a data radio bearer (DRB) associated with the DAPS handover,
in case that the random access procedure is successfully completed, receive, from the terminal, a first PDCP status report for the DRB,
transmit, to the terminal, a radio resource control (RRC) message including an indication to release a connection with a source base station, and
receive, from the terminal, a second PDCP status report for the DRB.
11. The base station of claim 10 , wherein the DRB associated with the first PDCP status report is at least one of acknowledged mode (AM) DRB or unacknowledged mode (UM) DRB.
12. The base station of claim 10 , wherein the DRB associated with the second PDCP status report is an acknowledged mode (AM) DRB.