Uplink Timing Reference Management in Carrier Aggregation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing mobile communication systems, particularly in LTE, face challenges in improving uplink data rate and end-user Quality of Service (QoS) due to limitations in managing multiple uplink carriers and timing references, which are essential for efficient data transmission.
Innovation Solution
The proposed method involves configuring secondary carriers into a Secondary-Timing Advance Group (S-TAG), deactivating the downlink timing reference carrier, and determining if other activated secondary carriers can serve as new downlink timing references, allowing for dynamic adjustment of uplink transmission timing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple downlink carriers are configured in a Secondary-Timing Advance Group, then uplink data rate is improved, but timing management complexity increases
Solution Approach 1:
The patent divides the timing management function by introducing a specific downlink timing reference carrier within the S-TAG. This segmentation allows different carriers to have different roles (reference vs. non-reference), simplifying the overall timing management architecture while supporting multiple carriers for increased data rate.
Solution Approach 2:
The downlink timing reference carrier serves multiple functions: it provides the timing reference for uplink transmission, enables random access procedures, and facilitates timing alignment across multiple carriers in the S-TAG. This multi-functionality reduces the need for separate mechanisms for each carrier.
2Adaptability or versatility
If a downlink timing reference carrier is deactivated, then system adaptability is improved, but timing reference availability may be compromised
Solution Approach 1:
The patent enables dynamic reconfiguration of the downlink timing reference carrier within the S-TAG. When the original reference carrier is deactivated, the system can dynamically select a different carrier to serve as the new timing reference, maintaining timing reference availability while adapting to changing network conditions.
Solution Approach 2:
The system prepares for potential reference carrier deactivation by having mechanisms in place to identify and switch to alternative timing reference carriers within the S-TAG. This cushioning approach ensures that timing reference availability is maintained even when carriers are deactivated for various reasons.
3Reliability
If dynamic switching of downlink timing reference carrier is implemented, then system reliability is improved, but procedure complexity increases
Solution Approach 1:
The patent implements a self-service mechanism where the terminal autonomously identifies and switches to a new downlink timing reference carrier within the S-TAG when the original reference carrier is deactivated. This self-service approach improves reliability by ensuring continuous timing reference availability while avoiding the need for complex network-controlled switching procedures.
Data Source
AI summary
The present invention relates to a method and apparatus for transmitting data using a multi-carrier in a mobile communication system. The method of transmitting data in user equipment of a wireless communication system using a carrier aggregation technique according to an embodiment of the present invention includes the steps of setting secondary cells included in an S-TAG (Secondary-Timing Advance Group) configured of only secondary cells (SCells), deactivating a downlink timing reference cell in the S-TAG; determining whether other activated secondary cells exist besides the deactivated downlink timing reference cell in the S-TAG, and when the other activated secondary cells exist in the S-TAG, setting one of the other activated secondary cells as a new downlink timing reference cell. According to the present invention, uplink transmission speed can be increased in the user equipment and user QoS can be improved by transmitting data using one or more uplink carriers in the terminal.