User Equipment Radio Link Failure Recovery via Conditional Handover

The patent implements conditional handover by delivering handover commands in advance to the UE before the actual handover is needed. The UE stores multiple candidate handover configurations and their associated execution conditions, then monitors these conditions during operation. When a condition is satisfied, the corresponding handover is executed automatically. This preliminary action approach ensures that handover commands are already available when needed, improving handover success rate while managing complexity through structured condition monitoring.

The patent applies preliminary action by pre-configuring multiple candidate cells with their respective handover configurations before radio link failure occurs. When RLF is detected, the UE immediately checks whether any pre-configured candidate cells satisfy their execution conditions. If a suitable candidate exists, the handover is executed directly without initiating a cell selection procedure or starting a monitoring timer. This approach eliminates the time loss associated with cell selection while maintaining reliable link failure recovery through pre-prepared handover options.

The patent resolves this contradiction by delivering handover commands in advance rather than at the moment of failure. The network provides the UE with multiple candidate handover configurations and their execution conditions before RLF occurs. The UE stores these configurations locally and monitors the conditions. When a condition is satisfied or RLF occurs, the corresponding handover is executed immediately using the pre-delivered command. This approach increases device complexity slightly for configuration management but dramatically reduces handover interruption time, achieving seamless handover with minimal service delay.