PC5 QoS Flow Remapping to SL-DRB in Sidelink Communication
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Solution Overview
Problem
Current wireless communication systems face challenges in efficiently remapping Quality of Service (QoS) flows for sidelink communication in next-generation networks, particularly in supporting high-data throughput and diverse communication services like voice over IP and multimedia, where existing solutions do not effectively manage QoS flow remapping for sidelink data radio bearers.
Innovation Solution
A method and apparatus are introduced from the perspective of User Equipment (UE) to support PC5 QoS flow remapping to SL-DRB, involving establishing sidelink communication, mapping PC5 QoS flows to SL-DRBs, and transmitting specific messages and control PDUs to confirm and manage the remapping process, ensuring seamless data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If QoS flow remapping is implemented for sidelink communication, then data transmission efficiency and reliability are improved, but system complexity increases due to additional message exchanges and mapping management
Solution Approach 1:
The source UE performs QoS flow remapping before data transmission by sending a PC5 RRC message to the target UE indicating the new SL-DRB mapping. This preliminary action allows both UEs to establish the correct mapping relationship in advance, ensuring efficient data transmission without requiring complex real-time coordination during actual data flow.
Solution Approach 2:
The PC5 RRC message serves as an intermediary carrier to transmit the QoS flow to SL-DRB mapping information between source UE and target UE. This intermediary mechanism simplifies the complexity by providing a standardized message structure for remapping notification, avoiding the need for complex direct coordination protocols between UEs.
2Reliability
If end-marker control PDU is transmitted after QoS flow remapping, then data transmission reliability is improved by confirming successful remapping, but transmission time increases due to additional confirmation steps
Solution Approach 1:
The source UE transmits an end-marker control PDU after successful QoS flow remapping to provide feedback confirmation to the target UE. This feedback mechanism ensures that the target UE knows the remapping has been successfully executed and can switch to the new SL-DRB mapping, thereby improving transmission reliability. The timing is optimized to send the end-marker only after lower layer confirmation or receipt of PC5 RRC complete message, minimizing unnecessary delays.
3Adaptability or versatility
If multiple SL-DRBs are configured for PC5 QoS flows, then adaptability of sidelink communication is improved, but device complexity increases due to multiple mapping management requirements
Solution Approach 1:
The patent divides the QoS flow management into separate SL-DRB mappings, allowing each PC5 QoS flow to be independently mapped to appropriate SL-DRBs based on service requirements. This segmentation enables flexible adaptation to different service types (e.g., voice over IP, multimedia) while maintaining manageable complexity through structured mapping relationships defined in PC5 RRC messages.
Data Source
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AI summary
A method and apparatus are disclosed from the perspective of a first User Equipment (UE) to support PC5 QoS flow to SL-DRB (Sidelink-Data Radio Bearer) remapping. In one embodiment, the method includes the first UE establishing a sidelink communication with a second UE (1405). The method further includes the first UE mapping a PC5 QoS flow of the sidelink communication to a first SL-DRB (1410). The method also includes the first UE transmitting a PC5 RRC (Radio Resource Control) message to the second UE, wherein the PC5 RRC message indicates the PC5 QoS flow is mapped to a second SL-DRB (1415). In addition, the method includes the first UE transmitting an end-marker control PDU (Protocol Data Unit) to the second UE after successful transmission of the PC5 RRC message has been confirmed by lower layer(s) or after receiving a PC5 RRC complete message corresponding to the PC5 RRC message from the second UE (1420).