SDAP End-Marker Signaling for QoS Flow-to-DRB Remapping
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Solution Overview
Problem
Existing 3GPP standards for New Radio (NR) wireless networks face challenges in ensuring in-order delivery of packets during QoS flow to data radio bearer (DRB) remapping, particularly in RLC unacknowledged mode, which can lead to user experience issues due to potential loss of SDAP end markers and buffering delays.
Innovation Solution
Enhanced methods for transmitting and receiving SDAP end markers with improved reliability, including hybrid automatic repeat request (HARQ) retransmission, PDCP duplication, and adaptive L1/L2 configurations, to ensure reliable QoS flow remapping and in-order delivery of packets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If SDAP end markers are transmitted in RLC unacknowledged mode during QoS flow remapping, then the remapping process is faster, but the reliability of packet delivery deteriorates due to potential loss of end markers
Solution Approach 1:
The transmitting UE proactively sends SDAP end marker control PDUs to indicate the last packet on the old DRB before completing the remapping. This preliminary action ensures the receiving UE is notified in advance of the mapping change, allowing it to buffer and reorder packets correctly without waiting for acknowledgment
Solution Approach 2:
The receiving UE sends SDAP end marker acknowledgments back to the transmitting UE to confirm receipt of the end marker. This feedback mechanism allows the transmitting UE to verify that the remapping notification was successfully received, enabling reliable delivery confirmation in unacknowledged mode
2Stability of the object's composition
If the receiving UE buffers packets to ensure in-order delivery during remapping, then packet delivery order is improved, but buffering delays increase latency
Solution Approach 1:
The receiving UE buffers packets only temporarily upon receiving the SDAP end marker control PDU, holding them until the acknowledgment is received. This limited preliminary buffering ensures in-order delivery without prolonged delays, as the buffer is released immediately once confirmation is obtained
Solution Approach 2:
The buffering behavior is dynamically adjusted based on the receipt of end marker acknowledgments. The UE buffers packets only when necessary (upon receiving end marker) and releases them immediately upon confirmation, creating a dynamic rather than static buffering strategy that minimizes latency
Data Source
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AI summary
The present application relates to devices and components including apparatuses, systems, and methods for technologies for signaling related to quality of service flow to data radio bearer mapping updates in wireless networks.