Conditional Handover Signaling for Reliable Non-Terrestrial Cell Selection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In non-terrestrial networks (NTN), handover reliability is challenged by the indistinct difference in reference signal strength across cell centers and edges, exacerbated by weather impairments, leading to delayed or premature handovers due to inappropriate RSRP/RSRQ threshold configurations.
Innovation Solution
A method for conditional handover that includes acquiring configuration information of candidate cells and sending a message with execution conditions, such as reference signal and state conditions, to guide terminal devices in selecting suitable target cells for handover, reducing real-time calculations and signaling overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If RSRP/RSRQ threshold is configured excessively high, then handover triggering is delayed, but handover reliability deteriorates due to premature or frequent triggering
Solution Approach 1:
The patent changes the handover triggering parameters from using only RSRP/RSRQ thresholds to a composite evaluation mechanism that incorporates execution state conditions (location, velocity, acceleration) alongside reference signal conditions. This parameter transformation allows the system to adapt handover timing dynamically based on terminal movement characteristics, resolving the contradiction between timely and reliable handover triggering.
Solution Approach 2:
The patent introduces dynamic execution state conditions that adapt to terminal movement patterns. By evaluating location, velocity, and acceleration in real-time, the handover mechanism becomes dynamic rather than static, allowing optimal handover timing that accounts for both signal quality and terminal motion state, thus improving both reliability and timing accuracy.
2Reliability
If RSRP/RSRQ threshold is configured low, then handover triggering is timely, but handover reliability deteriorates due to premature or frequent triggering
Solution Approach 1:
The patent transforms the handover decision parameters from simple signal strength thresholds to a multi-dimensional evaluation including execution state conditions. This allows the system to distinguish between genuine handover opportunities and false triggers caused by temporary signal fluctuations, improving reliability while maintaining timely response.
Solution Approach 2:
The patent implements feedback mechanisms by continuously monitoring terminal execution state (location, velocity, acceleration) and using this information to adjust handover triggering decisions. This feedback loop prevents premature handovers by verifying that signal quality changes correlate with actual terminal movement patterns.
3Measurement precision
If conditional handover execution conditions include only reference signal conditions, then signaling overhead is reduced, but handover accuracy deteriorates due to inability to distinguish terminal movement patterns
Solution Approach 1:
The patent segments the handover execution conditions into distinct components: reference signal conditions (signal quality) and execution state conditions (terminal movement characteristics). This segmentation allows the system to evaluate multiple factors independently and combine them for accurate handover decisions, improving precision without overwhelming complexity.
Solution Approach 2:
The patent performs preliminary evaluation of execution state conditions before triggering handover. By pre-assessing terminal location, velocity, and acceleration, the system prepares accurate handover decisions in advance, improving measurement precision while managing complexity through structured preliminary analysis.
4Measurement precision
If conditional handover uses comprehensive execution conditions including location and velocity, then handover accuracy improves, but signaling overhead and calculation complexity increase
Solution Approach 1:
The patent divides comprehensive execution conditions into manageable segments: reference signal conditions and execution state conditions. This segmentation enables modular evaluation of multiple parameters (location, velocity, acceleration) without creating overwhelming calculation complexity, as each parameter can be assessed independently and combined systematically.
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
Provided are a conditional handover method, a communication node, and a storage medium. The method includes: in response to determining that a second communication node performs a conditional handover, acquiring configuration information of at least one candidate cell; and sending a first message to the second communication node, where the first message includes the configuration information of the at least one candidate cell and a conditional handover execution condition, the first message is used to instruct the second communication node to select at least one candidate cell meeting the execution condition from the at least one candidate cell as a target cell and to perform a handover to the target cell according to the configuration information, where in response to the target cell being a non-terrestrial network cell, the execution condition includes a reference signal condition and an execution state condition.