Cell Group Configuration for Uplink Timing Advance Management
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Solution Overview
Problem
Current cellular network technologies face challenges in efficiently managing multiple timing advance groups (TAGs) in uplink transmission, leading to excessive timing differences between TAGs, which can result in network performance deterioration and unwanted interference.
Innovation Solution
A method for wireless devices to receive RRC messages configuring cell groups, allowing for the transmission of sounding reference signals (SRS) overlapping in time between cells within the same TAG, and dropping configured SRS transmissions if they overlap with preambles in other cells, while ensuring sufficient power for parallel transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple timing advance groups are used for uplink transmission, then the network can support more cells and improve coverage, but excessive timing differences between TAGs occur leading to network performance deterioration and unwanted interference
Solution Approach 1:
The patent segments cells into different cell groups (TAGs) with distinct timing advance values, allowing independent timing management for each group. This segmentation enables the network to support multiple timing advances simultaneously, improving coverage while controlling timing differences within each segment to maintain performance reliability.
Solution Approach 2:
The patent applies different timing advance configurations to different cell groups locally. Each TAG receives customized timing parameters based on its specific propagation conditions, allowing optimal local performance while managing overall network timing differences to prevent interference.
2Productivity
If SRS transmissions are allowed to overlap in time between cells in the same TAG, then uplink transmission efficiency is improved, but power requirements increase for parallel transmission
Solution Approach 1:
The patent dynamically manages SRS transmissions by allowing temporal overlaps within the same TAG when power conditions permit, while providing mechanisms to adjust and drop transmissions when power becomes limiting. This dynamic approach maximizes transmission efficiency during favorable conditions while maintaining reliability during power-constrained scenarios.
3Reliability
If SRS transmissions are dropped when overlapping with preambles, then timing synchronization is maintained, but transmission opportunities are reduced
Solution Approach 1:
The patent segments the network into multiple TAGs, allowing SRS transmissions to proceed in one TAG even when preambles are transmitted in another TAG. This segmentation reduces the need to drop transmissions while maintaining timing synchronization within each TAG, thereby preserving both reliability and transmission opportunities.
Data Source
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AI summary
A wireless device transmits one packet on a second cell in symbols of a subframe. The symbols comprise the last symbol of the subframe. The wireless device transmits a sounding reference signal (SRS) in the last symbol on a first cell if: the wireless device is configured with cell groups; the wireless device has sufficient power to transmit the SRS and the packet; and the first cell is different from the second cell. The wireless device drops the SRS in the last symbol if the wireless device is not configured with cell groups.