MAC PDU Transmission via Control Uplink Grants for Lower Latency
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Solution Overview
Problem
The challenge in wireless communication systems is to efficiently utilize limited radio resources for transmitting data and control information while minimizing latency and delay, particularly in applications that are latency-sensitive.
Innovation Solution
A method and apparatus for transmitting a Medium Access Control (MAC) protocol data unit (PDU) based on a control uplink grant, involving the steps of transmitting information indicating the amount of MAC control elements to be sent, receiving a control uplink grant, constructing a MAC PDU, and transmitting it using the grant, with prioritization of higher-priority MAC CEs when resources are limited.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a unified uplink grant is used for both data and MAC CE transmissions, then resource allocation is simplified, but processing time and latency increase due to combined handling requirements
Solution Approach 1:
The patent segments the uplink grant into two distinct types: data UL grant for data transmissions and control UL grant for MAC CE transmissions. This segmentation allows each grant type to be processed independently with optimized handling procedures, reducing overall processing time while maintaining resource allocation efficiency
Solution Approach 2:
The patent introduces a grant type indicator as an intermediary element that identifies whether a received UL grant is for data or control purposes. This indicator enables the UE to quickly determine the appropriate processing path without complex analysis, reducing processing latency while maintaining simplified resource allocation
2Productivity
If multiple MAC CEs are transmitted together in a single MAC PDU, then resource utilization improves, but latency increases for high-priority CEs due to lower-priority CEs occupying resources
Solution Approach 1:
The patent implements dynamic resource allocation where the UE determines whether to include multiple MAC CEs in a single PDU based on real-time conditions including available resources, CE priorities, and transmission requirements. This dynamic approach allows high-priority CEs to be transmitted immediately when resources are limited, while allowing resource sharing when conditions permit, thus balancing utilization efficiency with latency requirements
Solution Approach 2:
The patent applies different handling rules to different MAC CEs based on their priority levels and specific requirements. High-priority CEs receive preferential treatment with guaranteed transmission opportunities, while lower-priority CEs can wait for resource availability. This localized quality differentiation ensures that critical control information is transmitted without delay while still achieving good overall resource utilization
3Productivity
If the UE waits for a control UL grant to transmit MAC CEs, then resource allocation efficiency improves, but transmission delay increases
Solution Approach 1:
The patent implements preliminary action by having the network pre-configure control UL grants for MAC CE transmissions. These grants are prepared in advance and can be immediately activated when MAC CEs need to be transmitted, eliminating the need for real-time grant acquisition and thus reducing transmission delay while maintaining efficient resource allocation
Solution Approach 2:
The patent ensures continuity of useful action by maintaining control UL grants in a ready state at the network side, allowing immediate transmission of MAC CEs when needed. This continuous readiness state eliminates idle waiting time while preserving the efficiency benefits of controlled resource allocation, as grants are continuously available but only activated when actual transmission is required
Data Source
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AI summary
The present disclosure relates to a method of transmitting a Medium Access Control (MAC) protocol data unit (PDU) by a user equipment (UE) in a wireless communication system. Especially, the method includes the steps of based on a first Medium Access Control (MAC) control element (CE) being triggered, transmitting, on a data uplink (UL) grant to a network, information indicating an amount of the first MAC CE to be transmitted; receiving a control UL grant from the network; constructing a MAC protocol data unit (PDU) including the first MAC CE; and transmitting the MAC PDU using the control UL grant.