Method and device for retransmitting data

A method for retransmitting data, comprising:

• receiving, by a first device, on a data radio bearer (DRB), a first packet data convergence protocol (PDCP) protocol data unit (PDU) transmitted by a second device, wherein the first device is a radio access network (RAN) and the second device is a user equipment (UE) that does not send a PDCP status report;
• performing, by the first device, on a PDCP layer of the first device, an integrity protection (IP) verification for the first PDCP PDU;
• transmitting, by the first device, the PDCP status report to the second device when the IP verification for the first PDCP PDU is failed and a trigger condition is met, wherein the triggering condition is used for triggering the first device to transmit the PDCP status report to the second device;
• wherein the transmitting, by the first device, the PDCP status report to the second device when the IP verification for the first PDCP PDU is failed and the trigger condition is met, comprises:
• triggering the first device to transmit the PDCP status report to a second device when the IP verification for the first PDCP PDU is failed and a time interval after the failed IP verification for the first PDCP PDU is greater than or equal to a second threshold;
• wherein a timer is configured on the PDCP layer of the first device, wherein the method further comprises:
• stopping the timer after the first device transmits the PDCP status report to the second device;
• restarting the timer when the IP verification performed on the PDCP layer of the first device for a second PDCP PDU is failed, wherein the second PDCP PDU is a first PDCP PDU with failed IP verification after the first PDCP PDU.