Conditional Handover Updates for Low-Latency 5G Mobility
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Solution Overview
Problem
Current 5G NR handover procedures are prone to failures due to reactive decision-making by the network, leading to inefficiencies and increased signaling delays, particularly in scenarios requiring ultra-low latency and high reliability.
Innovation Solution
Implementing a conditional handover procedure where user equipment receives initial and updated configurations from a base station, allowing it to evaluate and execute handovers based on predefined conditions, reducing reliance on network-initiated commands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the network performs reactive handover decision-making, then the handover process is simpler to implement, but handover reliability deteriorates and latency increases
Solution Approach 1:
The patent applies preliminary action by pre-configuring multiple candidate target cells and their associated execution conditions before the actual handover is needed. The network provides the UE with a set of candidate cells and conditions (e.g., measurement thresholds, signal quality criteria) in advance, so that when handover becomes necessary, the UE can immediately evaluate and execute without waiting for network decisions. This eliminates reactive decision-making while maintaining implementation simplicity.
Solution Approach 2:
The patent implements self-service by enabling the UE to autonomously evaluate execution conditions and decide when to perform handover based on pre-configured criteria. The UE monitors signal quality and other parameters locally, compares them against the pre-set conditions, and triggers handover independently without requiring continuous network control. This self-service approach improves handover reliability and reduces latency while keeping the decision-making logic simple through pre-established rules.
2Loss of time
If the network waits for measurement reports to trigger handover, then signaling is reduced, but handover latency increases
Solution Approach 1:
The patent applies preliminary action by pre-establishing execution conditions and candidate cell configurations before handover is needed. The network provides the UE with measurement conditions, threshold values, and target cell information in advance, eliminating the need to wait for measurement reports when handover becomes necessary. This enables immediate handover execution upon condition satisfaction, significantly reducing latency without requiring additional signaling messages.
Solution Approach 2:
The patent implements feedback by having the UE continuously monitor local signal quality and other parameters against pre-configured execution conditions. The UE evaluates these conditions in real-time using locally stored configuration data, and when conditions are met, triggers handover autonomously. This feedback mechanism operates without requiring network signaling, as the UE uses pre-provided criteria to make real-time decisions, thus reducing latency without increasing signaling overhead.
3Measurement precision
If the network provides detailed handover configuration, then handover precision improves, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the handover configuration into distinct, manageable components: candidate cell identifiers, execution conditions with specific thresholds, measurement parameters, and trigger criteria. Each component is independently configured and can be processed separately by the UE. This segmented approach enables precise handover evaluation through detailed conditions while keeping the overall configuration structure simple and organized, making it easier to implement and manage.
Solution Approach 2:
The patent implements local quality by providing UE-specific execution conditions and thresholds that are optimized for individual user scenarios. The network can configure different handover criteria for different UEs based on their specific needs, location, or service requirements. This allows high precision handover evaluation tailored to each UE's local conditions without requiring complex universal configuration, as each UE receives customized parameters that simplify the evaluation process while maintaining precision.
Data Source
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AI summary
The present disclosure relates to a user equipment comprising the following. A receiver of the UE receives from a base station, an initial configuration for a conditional handover in a higher-layer message, wherein the initial conditional handover configuration identifies one or more candidate handover cells and one or more execution conditions for executing the conditional handover. Processing circuitry of the UE inactivates or activates evaluation of conditional handover execution conditions for candidate handover cells, in response to the received initial conditional handover configuration. The processing circuitry performs, for each activated evaluation, the evaluation of the one or more conditional handover execution conditions as to whether to perform the conditional handover towards one of the candidate handover cells. The receiver receives, from the base station, a conditional handover configuration update in a lower-layer message, wherein the conditional handover configuration update instructs the UE to update the conditional handover configuration.