DAPS Mobility Radio Link Failure Handling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems face challenges in efficiently managing mobility procedures, particularly during make-before-break (MBB) mobility, where maintaining radio links and handling radio link failures (RLF) can lead to unnecessary transmissions and increased power consumption.
Innovation Solution
Implementing a dual active protocol stack (DAPS) mobility procedure that includes radio link monitoring (RLM) to detect consecutive out-of-sync indications and stop transmissions on the source cell after detecting an RLF, allowing for seamless handover to a target cell while reducing power consumption and avoiding residual data handling issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If radio link monitoring continues on source cell during MBB mobility, then mobility seamlessness is improved, but power consumption increases
Solution Approach 1:
The system performs preliminary detection of RLF condition before completely stopping monitoring. By detecting consecutive out-of-sync indications and identifying RLF status in advance, the system can proactively stop monitoring on the source cell, preventing unnecessary power consumption while maintaining mobility seamlessness through early warning mechanisms.
Solution Approach 2:
Instead of continuous full monitoring, the system applies partial monitoring by stopping RLF monitoring on the source cell after RLF is detected. This partial action approach reduces power consumption by eliminating redundant monitoring on the source cell while maintaining sufficient monitoring on the target cell to ensure mobility reliability.
2Reliability
If transmission continues on source cell after RLF detection, then data completeness is improved, but unnecessary transmissions increase power consumption
Solution Approach 1:
The system uses feedback from RLM outcomes to control transmission behavior. When RLF is detected through consecutive out-of-sync indications, this feedback triggers immediate cessation of transmission on the source cell. This feedback mechanism ensures that transmission stops only when necessary, avoiding unnecessary power consumption while maintaining data completeness through intelligent control.
Solution Approach 2:
The system extracts and isolates the transmission function on the source cell separately from the target cell transmission. By taking out the source cell transmission component and independently controlling it based on RLF status, the system can eliminate unnecessary transmissions on the failed source cell while maintaining data flow through the target cell, thus reducing power consumption without compromising data completeness.
3Reliability
If dual active protocol stack is maintained during handover, then handover seamlessness is improved, but device complexity increases
Solution Approach 1:
The system segments the protocol stack management into distinct phases: active dual-stack phase during handover preparation and execution, and single-stack phase after handover completion. By segmenting the complexity temporally, the system maintains handover seamlessness through dual active stacks when needed while reducing complexity by deactivating one stack after handover, thus managing device complexity effectively.
Solution Approach 2:
The system dynamically adjusts the number of active protocol stacks based on handover phase. During handover execution, both source and target protocol stacks remain active to ensure seamlessness. After successful handover completion, the source protocol stack is deactivated, dynamically reducing complexity. This dynamic adaptation allows the system to maintain handover seamlessness while managing device complexity through flexible configuration.
Data Source
AI summary
The present disclosure relates to method and apparatus for mobility in wireless communications. According to an embodiment of the present disclosure, a method performed by a wireless device in a wireless communication system comprises: performing a dual active protocol stack (DAPS) mobility procedure for a mobility from a source cell to a target cell while maintaining a radio link for the source cell; performing a radio link monitoring (RLM) comprising a monitoring of a number of consecutive out-of-sync indications received on a radio link for the source cell during the DAPS mobility procedure; and after detecting a radio link failure (RLF) for the source cell based on the RLM, stopping a transmission on the radio link for the source cell during the DAPS mobility procedure.