Timing Advance Delay Handling in Carrier Aggregation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems, particularly in carrier aggregation (CA) and dual connectivity (DC) scenarios, user equipment (UE) faces challenges in making multiple timing adjustments simultaneously due to different transmission time intervals (TTIs) from various serving cells, leading to potential conflicts and undefined responses when applying different timing advance (TA) commands.
Innovation Solution
The UE employs a single constant TA adjustment delay or the maximum TA adjustment delay across all serving cells, regardless of the TTI lengths, to ensure simultaneous application of TA commands without conflicts, thereby simplifying the timing adjustment process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If different TA adjustment delays are applied for different TTI lengths, then processing efficiency is improved for each individual TTI, but conflicts occur when multiple TA commands need to be applied simultaneously
Solution Approach 1:
The patent changes the TA adjustment delay parameter from being variable (dependent on TTI length) to being fixed (constant value for all TTIs). This resolves the contradiction by eliminating the source of conflicts while maintaining processing efficiency through the fixed, predictable timing behavior.
Solution Approach 2:
The patent applies a universal TA adjustment delay value across all serving cells and TTI lengths, making the timing adjustment mechanism applicable uniformly regardless of the specific TTI configuration. This eliminates conflicts between different TA commands while maintaining efficiency.
2Reliability
If a single constant TA adjustment delay is used across all serving cells, then conflicts between multiple TA commands are avoided, but processing efficiency may be reduced compared to TTI-specific delays
Solution Approach 1:
The patent optimizes the constant TA adjustment delay parameter to achieve the best balance between reliability and efficiency. By carefully selecting the fixed delay value, the system maintains reliable timing alignment while minimizing the impact on processing efficiency.
3Loss of time
If TTI lengths are shortened to reduce latency, then response time is improved, but the complexity of managing multiple TA commands increases
Solution Approach 1:
The patent changes the TA adjustment delay from a variable parameter to a fixed parameter, which simplifies the management of multiple TA commands while allowing shortened TTI lengths to reduce latency. The fixed parameter approach eliminates the complexity of coordinating different delays across multiple short TTIs.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Systems and methods are provided for handling different timing advance (TA) adjustment delays corresponding to different transmission time intervals (TTIs) from different serving cells under carrier aggregation or dual connectivity. A user equipment (UE) selects and implements one TA adjustment delay even if two or more serving cells transmit with different TTIs. In one embodiment, the UE uses a predetermined TA adjustment delay for each of a plurality of TA commands received from serving cells with different TTI lengths. In another embodiment, the UE uses a TA adjustment delay that is a maximum value of the TA adjustment delays for the TTIs from the different serving cells.