NTN Cell Selection Using Trajectory and Service Time
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing non-terrestrial network (NTN) cell reselection and conditional handover methods in 5G NR do not ensure the selection of the optimal cell, leading to potential service duration and trajectory mismatches, resulting in increased power consumption due to frequent neighbor cell measurements.
Innovation Solution
A method and apparatus for selecting an NTN cell by determining trajectory and service time information based on received system parameters, prioritizing cells for reselection or handover to ensure optimal cell choice, reducing power consumption by selecting cells with longer service duration and favorable trajectories.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing NTN cell reselection and conditional handover methods are used, then cell selection is performed based on conventional criteria, but optimal cell selection is not ensured leading to service duration and trajectory mismatches
Solution Approach 1:
The patent changes the selection parameters from conventional signal strength-based criteria to trajectory-based parameters including service time, trajectory alignment, and relative motion characteristics. This allows the UE to select cells that provide longer service duration and better trajectory alignment, resolving the service duration mismatch problem while maintaining service continuity.
Solution Approach 2:
The patent performs preliminary trajectory analysis and service time calculation before cell selection. By pre-computing parameters such as time to closest approach, service duration, and trajectory alignment for candidate cells, the UE can make informed selection decisions that ensure optimal service continuity and avoid future service duration mismatches.
2Measurement precision
If frequent neighbor cell measurements are performed to ensure optimal cell selection, then cell selection accuracy improves, but power consumption increases
Solution Approach 1:
The patent extracts and prioritizes only the most critical measurement parameters needed for trajectory-based cell selection, such as service time and trajectory alignment metrics. By focusing measurements on these key parameters rather than performing comprehensive neighbor cell measurements, the UE achieves accurate cell selection while significantly reducing power consumption.
Solution Approach 2:
The patent performs measurements selectively based on trajectory conditions rather than continuously measuring all neighbor cells. When trajectory alignment and service time parameters indicate a suitable cell, the UE performs targeted measurements to confirm selection, avoiding excessive measurements and reducing power consumption while maintaining selection accuracy.
3Ease of operation
If cells are selected based on conventional criteria without trajectory consideration, then selection process is simple, but service duration and trajectory alignment are not optimized
Solution Approach 1:
The patent enables the UE to autonomously calculate trajectory-based parameters such as service time, trajectory alignment, and time to closest approach using available satellite ephemeris and UE position information. This self-service approach maintains operational simplicity while significantly improving service duration optimization, as the UE independently evaluates candidate cells based on trajectory metrics without complex network coordination.
Data Source
AI summary
A method for selecting a non-terrestrial network (NTN) cell by a user equipment (UE) is provided. The method includes receiving one or more system parameters from a serving NTN cell and a plurality of NTN neighbor cells, determining trajectory information associated with the plurality of NTN neighbor cells based on the one or more received system parameters, and selecting the NTN cell among the plurality of NTN neighbor cells to perform at least one of a cell reselection and a conditional hand over (CHO) based on the determined trajectory information associated with the plurality of NTN neighbor cells.