Cell Switching Timing Without L3 Signaling in NTN Networks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication systems face challenges in triggering cell switching procedures without Layer 3 (L3) signaling, particularly in scenarios where L3 signaling is not exchanged, such as in satellite communication with earth-fixed cells in Non-Terrestrial Networks (NTN), leading to inefficiencies and potential failures in cell switching.
Innovation Solution
A communication method and apparatus that utilize time information to initiate cell switching without L3 signaling, including the use of timers, indication information, and pre-configured uplink resources to ensure successful switching, along with mechanisms for timing alignment and reporting of timing advances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If cell switching is performed without L3 signaling, then switching speed and efficiency are improved, but reliability of switching procedure deteriorates due to lack of confirmation signaling
Solution Approach 1:
The terminal device is pre-configured with time information indicating when switching without L3 signaling should take effect. This preliminary configuration allows the device to automatically execute switching at the predetermined time without waiting for L3 signaling, thereby achieving fast switching while maintaining reliability through pre-planned coordination between network and terminal.
Solution Approach 2:
The patent introduces feedback mechanisms where the terminal device sends indication information to the network device to confirm switching completion, and the network device can send timing information to coordinate switching. This feedback loop ensures that even without full L3 signaling, both parties remain synchronized and can detect switching status, thereby maintaining reliability.
2Loss of energy
If switching without L3 signaling is implemented, then signaling overhead is reduced, but difficulty in triggering and coordinating switching increases
Solution Approach 1:
The patent uses time information as an intermediary mechanism to coordinate switching between network device and terminal device. Instead of complex L3 signaling, the predetermined time information acts as a common reference that both parties use to trigger switching simultaneously, simplifying the coordination process while reducing signaling overhead.
Solution Approach 2:
The time information serves multiple functions: it triggers switching at the terminal, coordinates the switching timing at the network device, and provides a common reference for both parties. This multi-functionality reduces the need for separate signaling messages, thereby reducing overhead while maintaining coordination capability.
3Measurement precision
If switching is triggered based on time information, then switching accuracy is improved, but complexity of timing management increases
Solution Approach 1:
The network device pre-calculates and provides time information to the terminal device before switching is needed. This preliminary action allows the terminal to simply follow the predetermined timing without complex real-time calculations, achieving accurate switching while keeping terminal complexity low.
Solution Approach 2:
The terminal device uses the received time information to autonomously determine when to switch without requiring continuous network coordination or complex timing algorithms. The device serves itself by independently executing switching based on the pre-provided time reference, simplifying timing management.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
This application provides a communication method and a communication apparatus. In the method, a terminal device receives time information from a first cell, where the time information indicates first time at which switching without layer 3 (L3) signaling takes effect; and performs switching from the first cell to a second cell based on the time information. In this solution, the terminal device triggers, based on the received time information, to start a switching procedure without L3 signaling, so that the switching procedure without L3 signaling is correctly started. This helps the terminal device correctly perform cell switching.