Buffer Status Report Method for Multi-LCG Uplink Allocation
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Solution Overview
Problem
Current buffer status report (BSR) methods in LTE communication systems are inadequate for reporting uplink buffer status when more than four logical channel groups (LCGs) are configured for user equipment (UE), leading to inefficient resource allocation.
Innovation Solution
A method for generating and sending a buffer status report that includes buffer indexes for up to eight LCGs, allowing the network-side device to accurately allocate uplink resources by using variable bit lengths for the buffer index and optional LCG identity, thereby supporting more than four LCGs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the BSR reports buffer status for each logical channel separately, then the network-side device can allocate uplink resources accurately, but the signaling overhead increases significantly
Solution Approach 1:
The patent merges multiple logical channels into logical channel groups (LCGs) and reports buffer status at the LCG level rather than individual logical channel level. This grouping approach reduces the number of BSR reports while still providing sufficient information for uplink resource allocation, thus resolving the contradiction between allocation accuracy and signaling overhead.
Solution Approach 2:
The patent designs a universal BSR structure that can handle both short BSR (single LCG) and long BSR (multiple LCGs) scenarios using the same reporting mechanism. The long BSR format can report buffer status for all four LCGs simultaneously, making the system versatile for different uplink data volumes and reducing the frequency of multiple separate reports.
2Productivity
If the UE establishes more radio bearers to handle increased service volume, then the service capacity increases, but the number of LCGs exceeds the four-LCG limitation of existing BSR formats
Solution Approach 1:
The patent introduces dynamic BSR formats that can adapt to different numbers of LCGs. The long BSR format dynamically includes buffer status information for multiple LCGs (up to four LCGs with 6-bit buffer indexes each), allowing the system to accommodate increased service volume and more radio bearers while maintaining BSR reporting capability.
Solution Approach 2:
The patent extends the BSR structure by adding another dimension - the long BSR format that can carry buffer status for multiple LCGs simultaneously. This dimensional extension allows the system to handle more than four LCGs by using multiple long BSR reports or combining information across different BSR types, thus adapting to increased service requirements.
3Device complexity
If the BSR uses a fixed 6-bit buffer index format, then the reporting structure remains simple, but the BSR cannot accommodate buffer reporting requirements when more than four LCGs are configured
Solution Approach 1:
The patent segments the BSR reporting into different formats (short BSR and long BSR) that can be selected based on the number of LCGs and uplink data conditions. The long BSR format segments buffer status information across multiple LCGs, with each LCG having its own buffer index field. This segmentation allows support for more than four LCGs while maintaining relatively simple fixed-width buffer index fields (6 bits per LCG).
Solution Approach 2:
The patent changes the BSR structure parameters by introducing variable-length buffer index fields and optional LCG identity fields. The buffer index can be 5-16 bits depending on the configuration, and LCG identity fields (when needed) are 3-4 bits. These parameter changes enable the BSR to accommodate more than four LCGs while balancing structure simplicity and adaptability.
Data Source
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AI summary
A method for sending a buffer status report BSR and user equipment are provided, to resolve a prior-art problem that a BSR cannot meet a buffer reporting requirement when more than four LCGs are configured for UE. The method for sending a BSR includes: generating, by user equipment UE, the BSR, where eight logical channel groups LCGs are configured for the UE, the BSR includes a buffer index of at least one of the eight LCGs, the buffer index of the LCG indicates an uplink buffer amount of the LCG, the BSR occupies X bytes, a buffer index of one LCG occupies N bits, X is an integer ranging from 1 to 17, N is an integer ranging from 5 to 16, and a case in which X is 1 and N is 6 does not exist; and sending, by the UE, the BSR to a network-side device.