NTN RACH Synchronization Using Satellite Trajectory and Elevation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication systems with non-terrestrial networks face inefficiencies and reliability issues in selecting between 2-Step and 4-Step RACH procedures, leading to suboptimal performance, increased network utilization, and higher power consumption.
Innovation Solution
A dynamic selection technique for UEs to choose between 2-Step and 4-Step RACH procedures based on satellite elevation angle and trajectory, enabling efficient communication by reducing message exchange and power consumption while maintaining reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a 2-Step RACH procedure is used, then communication efficiency and power consumption are improved, but reliability deteriorates due to lower resilience to connectivity issues
Solution Approach 1:
The patent implements dynamic selection between 2-Step and 4-Step RACH procedures based on real-time evaluation of link quality metrics including satellite elevation angle, trajectory, and predicted connectivity conditions. This allows the system to adapt the RACH procedure type dynamically rather than using a fixed approach, thereby optimizing both efficiency and reliability according to current operational conditions.
Solution Approach 2:
The system changes operational parameters by selecting different RACH procedure types (2-Step vs. 4-Step) based on evaluated conditions such as satellite elevation angle thresholds, predicted link quality, and network configuration. This parameter change enables the system to switch between efficiency-oriented and reliability-oriented communication modes as needed.
2Reliability
If a 4-Step RACH procedure is used, then reliability is improved through better resilience to connectivity issues, but communication efficiency and power consumption worsen due to increased message exchange
Solution Approach 1:
The system dynamically determines whether to use 4-Step RACH by evaluating current link quality conditions, satellite position, and predicted connectivity. This dynamic approach ensures that the more reliable 4-Step procedure is used only when necessary, rather than always, thereby maintaining reliability while improving overall communication efficiency.
Solution Approach 2:
The system changes the RACH procedure type parameter based on evaluated conditions including satellite elevation angle, trajectory predictions, and network configuration. This allows switching from the efficiency-oriented 2-Step procedure to the reliability-oriented 4-Step procedure when conditions warrant it.
3Productivity
If dynamic selection between 2-Step and 4-Step RACH is implemented, then communication efficiency is improved by reducing message exchange, but device complexity increases due to additional selection criteria evaluation
Solution Approach 1:
The system performs preliminary evaluation of satellite ephemeris data, elevation angles, and trajectory predictions before initiating RACH procedures. This advance preparation and pre-computation of selection criteria simplifies the actual selection process during runtime, reducing the perceived complexity during operation.
Solution Approach 2:
The patent replaces complex mechanical decision-making with algorithmic evaluations based on satellite orbital mechanics and geometric calculations. By substituting physical complexity with computational logic based on well-defined physical models, the system achieves efficient dynamic selection without excessive device complexity.
Data Source
AI summary
Disclosed are methods, systems, and computer-readable medium to perform operations including: determining a trajectory and an elevation angle of a first communications satellite of a non-terrestrial network relative to a user equipment (UE); determining, based on the trajectory and the elevation angle of the first communication satellite, whether one or more first criteria have been satisfied; and performing at least one of: (i) upon determining that the one or more first criteria have been satisfied, causing the UE to perform a 2-Step Random Access Channel (RACH) procedure with respect to the first communications satellite and the non-terrestrial network, or (ii) upon determining that the one or more first criteria have not been satisfied, causing the UE to perform a 4-Step RACH procedure with respect to the first communications satellite and the non-terrestrial network.