User Equipment CHO Retention for Radio Link Failure Recovery
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Solution Overview
Problem
In scenarios with highly frequent handovers, wireless communication networks face challenges such as radio link failures (RLF) and handover failures (HOF) due to late or early conditional handover (CHO) execution, leading to repeated CHO preparations that cause additional delay and signaling overhead.
Innovation Solution
Implementing a method where user equipment retains at least a part of conditional handover information during a re-establishment procedure following a failure, allowing for faster and more efficient updating and execution of consecutive CHO preparations without repeating all preparations from scratch.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a single CHO command is used for multiple consecutive CHOs to enable fast cell switching, then handover speed is improved, but the likelihood of RLF and HOF increases due to late or early CHO execution
Solution Approach 1:
The patent implements dynamic adjustment of CHO execution timing based on real-time radio conditions. The UE monitors radio quality metrics and dynamically determines whether to execute CHO early or wait for more favorable conditions, allowing the system to adapt to changing channel states and optimize the trade-off between handover speed and reliability
Solution Approach 2:
The patent changes key parameters including CHO execution timing, measurement thresholds, and evaluation criteria based on radio conditions. By adjusting these parameters dynamically, the system can prevent both early execution (which causes HOF) and late execution (which causes RLF), thereby improving reliability while maintaining fast handover capability
2Reliability
If CHO preparations are repeated after re-establishment procedure to ensure connectivity, then reliability is improved, but additional delay and signaling overhead occur
Solution Approach 1:
The patent performs preliminary actions by maintaining CHO configurations and preparation information in the UE before re-establishment is needed. When radio link failure occurs, the UE already has CHO configurations ready to use, eliminating the need to repeat the entire CHO preparation process after re-establishment, thus reducing delay while ensuring reliability
Solution Approach 2:
The patent ensures continuity of useful action by preserving CHO preparation information across the re-establishment procedure. Instead of interrupting and restarting CHO preparations, the system maintains the preparation state continuously, allowing the UE to quickly resume or complete handovers after re-establishment without significant delay
3Device complexity
If all CHO configurations are released after failure to free up resources, then device complexity is reduced, but further failures may occur due to lack of prepared CHO information
Solution Approach 1:
The patent implements a selective discarding and recovering strategy where CHO configurations are not completely discarded after failure. Instead, the UE recovers and retains essential CHO preparation information that can be reused or quickly updated, balancing resource management with the need to prevent further failures
Solution Approach 2:
The patent extracts and separates the essential CHO preparation information from the complete CHO configuration set. By taking out only the critical components needed for fast handover execution and retaining them after failure, the system reduces complexity by removing unnecessary configurations while maintaining reliability through preservation of essential handover capabilities
Data Source
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AI summary
The disclosure inter alia relates to a user equipment. The user equipment may comprise at least one processor. The user equipment may further comprise at least one memory storing instructions. The instructions, when executed by the at least one processor, may cause the user equipment to perform receiving conditional handover information from a first network node. The instructions, when executed by the at least one processor, may further cause the user equipment to perform retaining at least a part of the conditional handover information during a re-establishment procedure following a failure affecting a radio link of the user equipment.