MAC CE Multiplexing Across HARQ Schemes for Uplink Grants
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Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently multiplexing media access control (MAC) control elements (CEs) with varying reliability and latency requirements into MAC protocol data units (PDUs) associated with uplink grants, necessitating a solution that accounts for different QoS demands.
Innovation Solution
The solution involves grouping MAC CEs based on their reliability and latency needs and multiplexing them into PDUs using appropriate uplink grants, allowing for feedback-based or non-feedback-based retransmission schemes, and enabling scheduling requests (SRs) for urgent CEs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If HARQ feedback is enabled for all MAC CEs, then reliability is improved, but latency increases due to feedback overhead
Solution Approach 1:
The patent applies local quality by differentiating HARQ feedback requirements for different MAC CEs based on their specific reliability and latency needs. High-priority MAC CEs (e.g., BSR, PHR) receive HARQ feedback enabled for reliable transmission, while low-priority MAC CEs use HARQ feedback disabled for low-latency transmission. This selective approach optimizes each MAC CE's transmission characteristics according to its functional requirements.
Solution Approach 2:
The patent segments MAC CEs into different priority groups (first priority and second priority) with distinct HARQ feedback configurations. This segmentation allows the system to apply different retransmission schemes to different MAC CE types, enabling simultaneous optimization of reliability for critical CEs and latency for non-critical CEs within the same uplink transmission.
2Productivity
If multiple MAC CEs with different retransmission schemes are multiplexed into the same MAC PDU, then resource utilization is improved, but complexity of managing different schemes increases
Solution Approach 1:
The patent merges multiple MAC CEs with different retransmission scheme requirements into a single MAC PDU for transmission. By combining high-priority and low-priority MAC CEs in one PDU, the system maximizes uplink resource utilization and ensures that both reliability-critical and latency-critical CEs are transmitted efficiently in the same resource allocation.
Solution Approach 2:
The patent applies local quality by associating different HARQ process IDs with different priority MAC CEs within the same MAC PDU. High-priority MAC CEs are associated with first HARQ process IDs (feedback enabled), while low-priority MAC CEs are associated with second HARQ process IDs (feedback disabled). This differentiation manages complexity by providing clear identification and handling rules for each MAC CE type.
Data Source
AI summary
The present application relates to a method and an apparatus for multiplexing MAC CEs. One embodiment of the subject application provides a method including: receiving an uplink grant associated with a first retransmission scheme; selecting one or more first media access control (MAC) control elements (CEs) from a first number of MAC CEs according to the first retransmission scheme, wherein the one or more first MAC CEs are associated with the first retransmission scheme; and multiplexing the one or more first MAC CEs to a MAC protocol data unit (PDU) associated with an uplink grant.