NTN Downlink Configuration Timing Using RTT Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In non-terrestrial networks (NTN), the large distance between a terminal and a satellite leads to inconsistent understanding between the terminal and network devices due to the network device's inability to use updated downlink configurations before receiving feedback, as current processing delays are not accounted for in existing communication systems.
Innovation Solution
The terminal device determines the effective time of downlink configurations based on signal transmission round trip time (RTT) to ensure the network device can receive feedback and apply updated configurations consistently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the terminal device uses traditional processing delay to determine downlink configuration effective time, then the terminal can process configurations quickly, but the network device cannot use updated configurations before receiving feedback, leading to inconsistent understanding
Solution Approach 1:
The terminal device performs preliminary calculation of the effective time of downlink configuration by adding processing delay to the reception time. This preliminary action ensures that both terminal and network device can synchronize on when the configuration becomes effective, resolving the inconsistency problem before feedback is exchanged.
Solution Approach 2:
The patent introduces feedback mechanism where the terminal device feeds back the effective time information to the network device. This feedback loop allows the network device to adjust its configuration timing accordingly, ensuring both sides have consistent understanding of when the configuration takes effect.
2Reliability
If the network device waits for feedback from terminal device before applying updated downlink configuration, then configuration consistency is improved, but communication efficiency deteriorates due to large distance in NTN
Solution Approach 1:
The terminal device calculates and determines the effective time of downlink configuration in advance based on reception time and processing delay. This preliminary determination allows the network device to apply configurations without waiting for feedback, improving efficiency while maintaining synchronization through the pre-calculated effective time.
3Device complexity
If the terminal device considers only processing delay for downlink configuration, then the configuration process is simple, but the large distance in NTN causes inconsistent understanding between terminal and network side
Solution Approach 1:
The patent changes the parameter used for time calculation from simple processing delay to processing delay combined with reception time. By using the effective time = reception time + processing delay parameter combination, the system achieves consistent understanding between terminal and network device while maintaining reasonable calculation complexity.
Data Source
AI summary
A wireless communication method and a terminal device, the method including the following. A terminal device receives a media access control (MAC) control element (CE) transmitted from a network device, where the MAC CE indicates a first downlink configuration. The terminal device determines an effective time of the first downlink configuration and/or an effective time of the MAC CE according to a signal transmission RTT between the terminal device and the network device.