Patent ID: 11864275
Assignee: ZTE CORPORATION
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A data transmission system, comprising: a source distributed unit (DU) comprising a first processor and a first storage device, a centralized unit (CU) comprising a second processor and a second storage device, and a target DU comprising a third processor and a third storage device,
wherein the source DU is configured to report a packet data convergence protocol (PDCP) transmission status report to the CU, wherein the PDCP transmission status report enables the CU to determine which PDCP protocol data unit (PDU) data is not successfully received by a user equipment (UE);
wherein the CU is configured to receive the PDCP transmission status report, acquire PDCP PDU data which is not successfully received by the UE according to the PDCP transmission status report and resend the acquired PDCP PDU data to the target DU;
wherein the target DU is configured to receive and cache the acquired PDCP PDU data sent by the CU in advance;
wherein the CU is further configured to transmit a radio resource control (RRC) reconfiguration instruction to the UE via the source DU, and inform the UE to perform DU switching;
wherein the target DU is further configured to, after the DU switching from the source DU to the target DU is completed, receive a triggered PDCP status report from the UE, wherein the triggered PDCP status report informs the target DU of the PDCP PDU data which is not successfully received by the UE; and
wherein the target DU is further configured to retransmit the PDCP PDU data which is not successfully received by the UE in cached PDCP PDU data to the UE according to the triggered PDCP status report.