RRC Re-establishment Data Forwarding Between Base Stations
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Solution Overview
Problem
During connection failures between terminal devices and base stations, existing technologies face challenges in efficiently re-establishing data transmission between source and target base stations, particularly due to radio link failures, handover failures, and integrity protection check failures, which disrupt ongoing services.
Innovation Solution
A method involving a second access network device requesting context information from a first access network device, followed by the transmission of PDCP data packets and transmission status indication, ensures seamless data transmission during the re-establishment procedure, minimizing signaling overheads and maintaining service continuity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the terminal device initiates an RRC re-establishment request after connection failure, then the RRC connection can be re-established between the terminal device and the target base station, but data transmission between the source base station and target base station is disrupted
Solution Approach 1:
The source base station forwards PDCP data packets to the target base station before the RRC re-establishment procedure is completed. This preliminary action ensures that data transmission is not interrupted during the connection recovery process, as the target base station already has the necessary data packets ready to be transmitted to the terminal device after re-establishment.
Solution Approach 2:
The source base station acts as an intermediary by receiving PDCP data packets from the core network and forwarding them to the target base station. This intermediary role enables seamless data transmission during the handover and re-establishment process, bridging the gap between the source and target base stations without requiring direct communication between them.
2Productivity
If all PDCP data packets are transmitted during re-establishment procedure, then data continuity is maintained, but signaling overhead increases
Solution Approach 1:
Instead of transmitting all possible PDCP data packets during the re-establishment procedure, the system transmits only the necessary packets identified through the PDU service receiving information. This partial action approach maintains data continuity while avoiding the transmission of redundant packets, thereby reducing signaling overhead and energy consumption.
Solution Approach 2:
The target base station provides feedback to the source base station through PDU service receiving information, indicating which PDCP data packets have been received and which are still needed. This feedback mechanism enables the source base station to transmit only the necessary data packets, optimizing the balance between data continuity and signaling overhead.
Data Source
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AI summary
Embodiments of this application provide a data transmission method and device. The method is used in a re-establishment procedure, and includes: obtaining, by a first access network device, a first message from a second access network device, where the first message is used to request context information of a terminal device; and sending, by the first access network device, a data packet to the second access network device. The first access network device is a corresponding access network device of the terminal device before the re-establishment procedure, and the second access network device is a corresponding access network device when the terminal device initiates the re-establishment procedure. In the embodiments of this application, after obtaining the message used to request the context information of the terminal device, the first access network device sends the data packet to the second access network device, thereby implementing data transmission between the first access network device and the second access network device in the re-establishment procedure.