NTN Cell Handover Triggering Using Doppler Shift Thresholds
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Solution Overview
Problem
The conventional CHO mechanism in NTN communication fails to accurately determine the occasion for handover due to inaccuracies in trigger conditions, particularly in scenarios involving satellite motion and relative device motion, leading to unreliable handover processes.
Innovation Solution
A network resource configuration method that utilizes Doppler frequency shift and change rate thresholds, along with other signal quality metrics, to accurately identify the target cell for handover, ensuring timely and precise cell switching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional CHO trigger conditions (RSRP/RSRQ thresholds, location-based, timer-based) are used in NTN communication, then the handover mechanism can be implemented, but the accuracy of determining handover occasions deteriorates due to satellite motion and relative device motion causing moving overlapping areas
Solution Approach 1:
The patent introduces Doppler frequency shift and Doppler frequency shift change rate as new parameters for handover triggering. These parameters dynamically change with satellite motion and device motion, allowing the handover trigger conditions to adapt to the moving overlapping area scenario. The network device configures Doppler frequency shift thresholds and change rate thresholds that reflect the actual motion characteristics, enabling accurate determination of handover occasions despite the dynamic environment.
2Measurement precision
If Doppler frequency shift and change rate thresholds are configured for handover determination, then the accuracy and timeliness of handover triggering is improved, but the device complexity increases due to additional measurement and evaluation requirements
Solution Approach 1:
The patent leverages the existing Doppler frequency shift measurement capability that is already required for timing advance maintenance in NTN systems. By reusing this existing measurement for handover triggering purposes, the patent avoids adding separate measurement mechanisms. The terminal device uses the same Doppler frequency shift measurements for both timing advance calculation and handover condition evaluation, thereby achieving improved handover accuracy without proportionally increasing device complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Improves the accuracy and timeliness of handover processes in NTN communication by using Doppler frequency shift and change rate thresholds, enhancing user experience.
Implementation Method 1
the configuration information includes first threshold information corresponding to at least one candidate cell, and a first threshold includes at least one of a Doppler frequency shift threshold or a Doppler frequency shift change rate threshold
Implementation Method 2
a first threshold includes at least one of a Doppler frequency shift threshold or a Doppler frequency shift change rate threshold
Data Source
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AI summary
This application provides a network resource configuration method and apparatus, and relates to the field of communication technologies, to resolve a problem that a conventional trigger condition in an inter-communication cell switching mechanism cannot accurately determine an occasion for a terminal device handover, thereby improving accuracy and timeliness of the inter-communication cell handover of the terminal device. The method includes: A terminal device receives configuration information from a network device, where the configuration information includes first threshold information corresponding to at least one candidate cell, and a first threshold includes at least one of a Doppler frequency shift threshold, a timing advance TA rate threshold, or a Doppler frequency shift change rate threshold; the terminal device determines a target cell from the at least one candidate cell based on the configuration information; and the terminal device initiates a handover to the target cell.