Timing Advance Acquisition for Pre-Handover Uplink Synchronization
Solution Overview
Problem
Cell handover in wireless communication systems causes interruption in data transmission due to the lack of effective methods for obtaining Timing Advance (TA) before handover, leading to uncertainties in uplink synchronization.
Innovation Solution
A method and apparatus for a terminal device and network device to manage TA obtaining through signaling that instructs or configures operations like measurement and synchronization, allowing the terminal device to calculate or receive TA, and includes mechanisms for the network device to confirm TA acquisition before sending a switch command.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If cell handover is performed without TA obtaining, then handover speed is improved, but uplink synchronization reliability deteriorates
Solution Approach 1:
The patent applies preliminary action by enabling the terminal device to obtain TA information before the handover is executed. The network device sends TA information to the terminal device in advance (e.g., via RRC signaling or MAC CE), allowing the terminal to perform uplink synchronization prior to handover. This ensures that when handover occurs, the terminal is already synchronized, eliminating the need for post-handover synchronization procedures and thus improving both speed and reliability.
2Measurement precision
If TA is obtained through traditional methods after handover, then uplink synchronization accuracy is improved, but data transmission interruption time increases
Solution Approach 1:
The patent resolves this contradiction by performing TA acquisition in advance before handover execution. The network device provides TA information to the terminal device through pre-configuration or pre-measurement procedures (such as using downlink signal timing to calculate TA). This allows the terminal to maintain accurate uplink synchronization during and after handover without experiencing transmission interruptions, as the synchronization is already established beforehand.
3Reliability
If the network device manages TA obtaining through signaling, then TA acquisition reliability is improved, but signaling overhead increases
Solution Approach 1:
The patent applies universality by making the TA information serve multiple purposes. The same TA information that ensures reliable uplink synchronization is also used for uplink resource allocation and timing management. By integrating TA management into existing signaling frameworks (RRC configuration, MAC CE), the patent achieves reliable TA acquisition without adding separate dedicated signaling channels, thus minimizing overhead while maintaining reliability.
Data Source
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AI summary
A Timing Advance (TA) obtaining method and apparatus, a terminal device, and a network device are provided. The method includes: receiving, by a terminal device, a first signaling sent by a network device, wherein the first signaling is used to instruct, or configure, or activate a first operation on a first cell, and the first operation includes at least one of the following: measurement, downlink synchronization, or uplink synchronization; performing, by the terminal device, the first operation on the first cell, and obtaining, by the terminal device, a Timing Advance (TA) of the first cell based on the first operation.