Conditional Handover Thresholds for Wireless Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems face challenges in ensuring seamless handovers between cells, particularly in 5G networks, leading to potential disruptions and inefficiencies due to unreliable handover command delivery and increased signaling overhead.
Innovation Solution
The implementation of conditional handover techniques, where a lower threshold triggers early measurement reports and prepares target cells for handover, ensuring reliable handover command delivery by configuring a higher threshold for execution, thereby reducing user data interruption and improving handover robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If early measurement reports are triggered using a lower threshold to prepare target cells for handover, then handover reliability is improved, but signaling overhead increases
Solution Approach 1:
The system performs preliminary actions by triggering measurement reports at a lower threshold before the actual handover is needed. This allows target cells to be prepared in advance with handover commands, ensuring that when handover becomes necessary, the commands are already available and the target cell is ready, thereby improving handover reliability without requiring excessive signaling at the critical moment
Solution Approach 2:
The system changes the threshold parameter for triggering measurement reports, using a lower threshold than traditional methods. This parameter change enables earlier detection of suitable target cells and triggers preparation activities sooner, improving the likelihood of successful handover while managing signaling overhead through selective triggering based on the modified threshold criterion
2Reliability
If conditional handover with multiple target cells is implemented, then handover robustness is improved, but device complexity increases
Solution Approach 1:
The system segments the handover evaluation process by maintaining separate evaluation criteria and measurement report triggers for each potential target cell. Each target cell has its own conditional handover configuration with specific thresholds and parameters, allowing the UE to evaluate multiple candidates independently and select the most suitable one, thereby improving robustness while managing complexity through structured segmentation
Solution Approach 2:
The system implements partial evaluation by focusing UE resources on evaluating specific target cells that meet predefined criteria rather than continuously evaluating all possible target cells. The UE performs measurements and evaluations only for cells that trigger the conditional handover conditions, reducing overall computational complexity while maintaining robustness through targeted evaluation of promising candidates
3Reliability
If higher threshold is configured for handover execution, then false handover triggers are reduced, but handover latency increases
Solution Approach 1:
The system performs preliminary handover preparation by sending handover commands to target cells and configuring conditional handover parameters in advance, before the higher threshold is actually triggered. This preliminary action ensures that when the higher threshold is finally met, the handover execution can proceed quickly using pre-prepared configurations, thereby reducing the negative impact of latency while maintaining the reliability benefits of the higher threshold
Solution Approach 2:
The system dynamically adjusts the handover process by using different thresholds for different stages: a lower threshold for triggering measurement reports and preparation, and a higher threshold for final handover execution. This dynamic approach allows the system to balance between early preparation (improving reliability) and timely execution (reducing latency) by adapting threshold requirements to the specific phase of the handover process
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
An apparatus of a user equipment (UE) includes processing circuitry, where to configure the UE for conditional handover between a source base station (SBS) and a target base station (TBS) in a wireless network, the processing circuitry is to decode measurement configuration information from the SBS. The measurement configuration information indicating a measurement event and a first threshold associated with the measurement event to trigger measurement reporting. A measurement report is encoded for transmission to the SBS, the measurement report triggered based on the first threshold. RRC signaling is received from the SBS. The RRC signaling includes a conditional handover command indicating a second threshold for the measurement event, the second threshold being higher than the first threshold. A handover from the SBS to the TBS is performed based on the conditional handover command after detecting that the measurement event satisfies the second threshold.