RLC PDU Segmentation Parameter Determination for 5G
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In 5G mobile communication systems, the removal of RLC SDU concatenation to reduce latency increases RLC and upper layer overhead and decreases spectral efficiency, with larger RLC PDU segments risking fragmentation due to Transport Block Size limitations.
Innovation Solution
A method to determine segmentation parameters for RLC PDUs, including size and number of segments, using predictions of expected channel quality, traffic volume, and available bandwidth, employing static allocation, machine learning, or reinforcement learning algorithms to maximize segment size within the Transport Block Size, thereby optimizing payload to overhead ratio and reducing fragmentation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If RLC SDU concatenation is removed to reduce latency, then latency is reduced, but RLC and upper layer overhead increases and spectral efficiency decreases
Solution Approach 1:
The patent performs RLC segmentation in advance (pre-processing) before the UL grant is received, allowing the UE to prepare RLC PDUs without waiting for the grant. This preliminary segmentation action reduces latency while the predicted TBS optimization ensures spectral efficiency is maintained by adjusting segment sizes to fit transport blocks effectively.
Solution Approach 2:
The patent dynamically changes segmentation parameters (PDU size, number of segments) based on predicted TBS and channel conditions. By adjusting these parameters, the system optimizes the balance between overhead reduction and spectral efficiency, ensuring that segment sizes are maximized while fitting within transport block constraints.
2Productivity
If RLC PDU segment size is increased to reduce overhead, then overhead is reduced, but fragmentation risk increases due to Transport Block Size limitations
Solution Approach 1:
The patent uses predicted TBS as feedback to adjust segmentation parameters. The UE predicts the upcoming TBS and uses this information to determine optimal PDU segment sizes that maximize overhead efficiency while ensuring segments fit within the predicted transport block size, thereby minimizing fragmentation risk.
Solution Approach 2:
The patent makes segmentation parameters dynamic rather than static. The PDU size and number of segments are adjusted based on predicted channel conditions and TBS, allowing the system to adapt to varying transport block sizes and minimize fragmentation while maintaining high overhead efficiency.
Data Source
AI summary
A technique for determining segmentation parameters for use in segmenting Radio Link Control, RLC, Protocol Data Units, PDUs, in an RLC preprocessing procedure performed by a User Equipment, UE, prior to receiving an Uplink, UL, grant for transmission of the RLC PDUs is disclosed, wherein the segmentation parameters comprise a size of RLC PDU segments and a number of RLC PDU segments to be included into a physical layer Transport Block, TB. A method implementation of the technique comprises determining (S302) a TBS prediction of an expected physical layer Transport Block Size, TBS, determining (S304) an observation prediction of at least one of an expected channel quality, an expected traffic volume and an expected available bandwidth observable during transmission of the RLC PDUs, and determining (S306) the size of RLC PDU segments and the number of RLC PDU segments based on the TBS prediction and the observation prediction, wherein the size of RLC PDU segments and the number of RLC PDU segments are determined to maximize the size of RLC PDU segments while keeping a total size of the number of RLC PDU segments within the expected TBS.