Method and apparatus for qos-based pdcp sdu discard operation in wireless communication system

A method performed by a base station in a wireless communication system, the method comprising:

• generating configuration information on a first timer and a second timer for packet data convergence protocol (PDCP) service data unit (SDU) discarding;
• and
• transmitting the configuration information to a terminal,
• wherein, in case that a protocol data unit (PDU) set to which a PDCP SDU of a PDCP entity of the terminal belongs has low importance, the first timer is applied for the PDCP SDU, and
• wherein, in case that the PDU set does not have low importance, the second timer is applied for the PDCP SDU.

A terminal of a wireless communication system, the terminal comprising:

• a transceiver;
• and
• a controller,
• wherein the controller is configured to:
• receive, from a base station and through the transceiver, configuration information on a first timer and a second timer for packet data convergence protocol (PDCP) service data unit (SDU) discarding,
• obtain a PDCP SDU from an upper layer of a PDCP entity of the terminal,
• in case that a protocol data unit (PDU) set to which the PDCP SDU belongs has low importance, start the first timer for the PDCP SDU, and
• in case that the PDU set does not have low importance, start the second timer for the PDCP SDU.

A base station of a wireless communication system, the base station comprising:

• a transceiver;
• and
• a controller,
• wherein the controller is configured to:
• generate configuration information on a first timer and a second timer for packet data convergence protocol (PDCP) service data unit (SDU) discarding, and
• transmit the configuration information to a terminal through the transceiver,
• wherein, in case that a protocol data unit (PDU) set to which a PDCP SDU of a PDCP entity of the terminal belongs has low importance, the first timer is applied for the PDCP SDU, and
• wherein, in case that the PDU set does not have low importance, the second timer is applied for the PDCP SDU.