Adaptive PCell Interruption Timing for SCell Activation
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Solution Overview
Problem
Current wireless communication systems face delays in secondary cell (SCell) activation and deactivation due to the suspension of data communication during radio frequency frontend reconfiguration, which affects latency and efficiency in E-UTRA carrier aggregation.
Innovation Solution
The proposed solution involves modifying the timing of primary cell (PCell) interruption based on transmission time interval (TTI) and hybrid automatic repeat request (HARQ) processing time, allowing for earlier SCell activation and deactivation by specifying delays for PCell interruption in subframes, such as not occurring before subframe n+5 for 1 ms TTI with 4 subframe HARQ processing time, or subframe n+2 for subslot TTI.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If SCell activation/deactivation is performed with standard TTI timing, then radio frequency frontend reconfiguration is completed reliably, but data communication interruption time increases
Solution Approach 1:
The patent applies dynamics by making the interruption timing adaptive rather than fixed. The base station determines the actual interruption time based on real-time RF frontend reconfiguration status and reports this to the UE. This dynamic adjustment allows the system to complete reconfiguration reliably while minimizing unnecessary interruption time, resolving the contradiction between reliability and time loss.
Solution Approach 2:
The patent changes the parameter of interruption timing from a predetermined fixed value to a variable value based on actual reconfiguration needs. By modifying the timing parameter dynamically according to the specific TTI length and reconfiguration status, the system achieves both reliable completion of RF frontend reconfiguration and reduced data communication interruption.
2Manufacturing precision
If PCell interruption is delayed to allow RF frontend reconfiguration, then SCell activation/deactivation is completed accurately, but latency increases
Solution Approach 1:
The patent applies preliminary action by having the base station perform RF frontend reconfiguration in advance before the actual SCell activation or deactivation takes effect. The base station starts the reconfiguration process early, then uses the determined interruption time to ensure the configuration is complete before data communication resumes, thereby achieving accurate activation/deactivation with reduced latency.
Solution Approach 2:
The patent implements feedback by having the base station report the actual RF frontend reconfiguration status and determined interruption time to the UE. This feedback mechanism allows the UE to adjust its timing accordingly, ensuring accurate SCell activation/deactivation while minimizing unnecessary delays and reducing overall latency.
3Adaptability or versatility
If standard TTI length is used for PCell interruption, then system compatibility is maintained, but transmission efficiency decreases
Solution Approach 1:
The patent applies dynamics by making the interruption timing adaptable to different TTI lengths and reconfiguration scenarios. The base station determines the appropriate interruption time based on the actual TTI length used in the system, whether standard or shortened. This dynamic adaptation maintains system compatibility across different configurations while optimizing transmission efficiency for each specific scenario.
Solution Approach 2:
The patent achieves universality by creating a mechanism that works across multiple TTI configurations (standard TTI and shortened TTI) without requiring separate handling for each case. The base station's determination of interruption time based on actual reconfiguration status provides a universal solution that maintains compatibility while improving efficiency for both standard and shortened TTI modes.
Data Source
AI summary
Systems and methods provide solutions for PCell interruption for SCell activation and deactivation. A user equipment (UE) may select the delay of PCell interruption based on the transmission time interval (TTI) and the processing time (e.g., the hybrid automatic repeat request (HARD) processing time). A UE may be configured to process a physical downlink shared channel (PDSCH) comprising an activation command or a deactivation command in a first subframe for an SCell. In response to the activation or deactivation command, based on a TTI length corresponding to the PDSCH, the UE determines the delay for PCell interruption. The delay corresponds to a selected second subframe after the first subframe, wherein a first delay for a first TTI length is longer than a second delay for a second TTI length, and wherein the second TTI length is a shortened TTI (sTTI) compared to the first TTI length.