Conditional Handover and PSCell Change Failure Recovery
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Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently managing failure recovery during the joint operation of conditional handover and conditional PSCell addition or change, leading to connection interruptions and inefficiencies in 5G/NR networks.
Innovation Solution
Implementing a failure recovery procedure that includes triggering a joint operation of conditional handover and conditional PSCell change, determining failure events, and performing recovery procedures such as RRC re-establishment and fast MCG/SCG recovery to handle failures in the joint operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If joint operation of conditional handover and conditional PSCell addition or change is implemented, then handover efficiency and network performance are improved, but system complexity and difficulty of failure recovery increase
Solution Approach 1:
The patent segments the joint operation failure recovery into distinct scenarios: MCG link failure, SCG link failure, CHO execution failure, and CPC execution failure. Each scenario has a dedicated recovery procedure, simplifying the overall complex failure recovery process by dividing it into manageable, scenario-specific segments.
Solution Approach 2:
The patent establishes preliminary failure recovery configurations before joint operation failures occur. The network pre-configures recovery parameters, alternative cell lists, and recovery conditions, so that when a failure occurs, the UE can immediately execute the pre-planned recovery procedure without complex real-time decision-making.
2Loss of time
If fast MCG link recovery is configured, then connection interruption time is reduced, but requirements for network configuration and coordination increase
Solution Approach 1:
The network pre-configures fast MCG link recovery parameters including alternative PCell lists, recovery conditions, and transmission resources before failures occur. This preliminary setup enables rapid recovery by eliminating the need for complex real-time configuration exchanges during actual failure events.
Solution Approach 2:
The UE autonomously executes fast MCG link recovery by independently evaluating pre-configured recovery conditions and selecting appropriate alternative PCells from the pre-provided list, without requiring complex real-time network coordination or additional signaling during the recovery process.
3Reliability
If conditional PSCell change execution is halted upon CHO failure, then resource conflicts are avoided, but handover recovery time increases
Solution Approach 1:
The patent dynamically adjusts CPC execution based on CHO status. When CHO succeeds, CPC continues normally. When CHO fails, CPC is halted to avoid conflicts. This dynamic adaptation ensures reliability while minimizing time loss by only pausing CPC when necessary.
Solution Approach 2:
The system implements feedback mechanisms where the UE reports CHO execution results to the network, which then provides feedback commands to either continue or halt CPC execution. This feedback loop ensures reliable conflict avoidance while enabling rapid resumption of CPC when CHO recovery is successful.
Data Source
AI summary
Methods and apparatuses for a joint operation of a conditional handover (CHO) and a conditional primary secondary cell group (SCG) cell (PSCell) addition/change (CPA/CPC) in a wireless communication system. A method of a UE comprises triggering a joint operation of a CHO and a CPC and determining whether the CHO fails while performing the joint operation of the CHO and the CPC. The method further includes halting a CPC execution condition evaluation or a CPC execution based on a determination that the CHO fails and performing a failure recovery procedure for the joint operation of the CHO and the CPC.