Conditional Handover RLF Reporting for Mobility Failure Classification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current RLF reporting after successful conditional handover does not provide clear insights into whether the handover configuration was improperly timed or if the target cell failed to configure the UE correctly, leading to ambiguity in network optimization.
Innovation Solution
The UE retains and logs additional information in the RLF report, including successful handover details and CHO configuration from the source cell, along with elapsed times and measurements, to enable the network to better classify mobility failure types and optimize handover configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the UE deletes CHO configuration after successful handover execution, then the UE memory is cleared and preparation for new handover is enabled, but the network loses the ability to determine whether the handover was properly timed or if the target cell failed to configure the UE correctly
Solution Approach 1:
The patent segments the CHO configuration storage into different retention states: the configuration is retained in a specific state after successful handover execution and only deleted when explicitly instructed by network signaling or after a timer expires. This segmentation allows the UE to maintain handover configuration information for network analysis purposes while still preparing for new handovers, resolving the contradiction between memory management and information preservation.
Solution Approach 2:
The patent implements preliminary retention of CHO configuration information after successful handover execution, before the UE prepares for new handover configurations. This preliminary action ensures that the network receives complete RLF report information including handover configuration details, enabling the network to determine whether the handover was properly timed or if the target cell failed to configure the UE correctly, while still allowing for subsequent memory clearance when appropriate.
2Loss of information
If the UE retains all handover configuration information indefinitely, then the network has complete information for analysis, but the UE memory is occupied and cannot be used for new configurations
Solution Approach 1:
The patent implements dynamic memory management for CHO configuration information, where the retention state changes based on network signaling and timer expiration. The UE retains configuration information in a controlled state after successful handover, but can clear it when network instructed or after timer expiry. This dynamic approach allows the UE to maintain information for network analysis while freeing memory for new configurations, resolving the contradiction between information retention and memory availability.
Solution Approach 2:
The patent implements preliminary retention of CHO configuration information for a limited duration or under specific conditions before automatic clearance or network-instructed deletion. This preliminary retention ensures the network receives complete RLF report information while preventing indefinite memory occupation, allowing the UE to balance information preservation with memory availability for new handover preparations.
3Device complexity
If the network does not receive detailed handover configuration information in RLF reports, then the reporting mechanism remains simple, but the network cannot classify mobility failure types (too early, too late, wrong cell)
Solution Approach 1:
The patent implements preliminary retention and inclusion of handover configuration information in RLF reports, enabling the network to receive detailed data about the handover process. This preliminary action provides the network with the necessary information to classify mobility failure types (too early, too late, wrong cell) accurately, while the reporting mechanism itself remains a standard extension that does not significantly increase complexity.
Solution Approach 2:
The patent enhances the RLF report as a feedback mechanism from the UE to the network, including detailed handover configuration information such as source cell, target cell, and configuration parameters. This feedback enables the network to analyze the handover process and classify failure types accurately, providing the network with the insights needed to optimize mobility robustness while maintaining a relatively simple reporting structure.
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
Systems and methods are disclosed for enhancements to Mobility Robustness Optimization (MRO) in case of Radio Link Failure (RLF) after successful (conditional) handover. In one embodiment, a method performed by a wireless device comprises receiving a handover (HO) configuration or conditional handover (CHO) configuration from a source cell and declaring a RLF in association with a HO or CHO to a target cell. The method further comprises generating a RLF report responsive to declaring the RLF, the RLF report comprising the HO configuration or CHO configuration, a successful HO report, information about one or more associated time durations, one or more radio link measurements for one or more CHO candidate cells associated to the CHO configuration received from the source cell, or any combination thereof. The method further comprises transmitting the RLF report to a network node.