Secondary Timing Advance Acquisition via Random Access
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Solution Overview
Problem
In LTE systems, configuring secondary cells without using existing primary cell timing advances leads to increased signaling overhead and resource wastage due to the need for terminals to initiate random access procedures to obtain secondary timing advances, which can result in uplink collisions and resource mismanagement.
Innovation Solution
A method where a terminal initiates a random access procedure to obtain a secondary timing advance after receiving a secondary cell activation command, thereby reducing unnecessary signaling overhead and resource waste by synchronizing uplink transmissions with the base station using calibrated timing advance commands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a terminal obtains a secondary timing advance by initiating random access in the secondary cell after secondary cell configuration, then the secondary timing advance can be acquired, but signaling overhead and system resources are increased and wasted
Solution Approach 1:
The patent applies preliminary action by having the terminal obtain the secondary timing advance immediately after secondary cell configuration, before actual data transmission begins. This is achieved by initiating random access procedure right after the secondary cell is configured, rather than waiting until it is activated. The timing advance is obtained in advance, so when the secondary cell becomes active for data transmission, the terminal already has the necessary timing advance value, avoiding the need for additional random access procedures and reducing signaling overhead.
2Reliability
If a terminal obtains a secondary timing advance by initiating random access in the secondary cell, then the timing synchronization is achieved, but system resources are wasted
Solution Approach 1:
The patent applies preliminary action by performing the random access procedure to obtain timing advance immediately after secondary cell configuration, before the cell is activated for data transmission. This ensures uplink synchronization is established in advance, so when the secondary cell becomes active, the terminal is already synchronized, avoiding additional random access procedures and conserving system resources.
3Measurement precision
If random access is initiated frequently to obtain secondary timing advance, then timing accuracy is maintained, but signaling overhead increases
Solution Approach 1:
The patent applies preliminary action by obtaining the timing advance immediately after secondary cell configuration, establishing timing accuracy in advance. The terminal then maintains this timing advance during the time alignment timer period without needing to initiate additional random access procedures, thus maintaining timing accuracy while minimizing signaling overhead.
Solution Approach 2:
The patent applies continuity of useful action by establishing the timing advance once and maintaining it continuously through the time alignment timer mechanism. Instead of repeatedly initiating random access procedures, the terminal continuously uses the obtained timing advance value within the valid period defined by the time alignment timer, ensuring continuous uplink synchronization without repeated signaling exchanges.
Data Source
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AI summary
Embodiments of the present invention provide a method and a device for obtaining a secondary timing advance. The method includes: after a secondary cell activation command is received or after a secondary cell is activated, if a secondary time alignment timer TAT of the secondary cell does not run, initiating, by a terminal, a random access procedure; and obtaining, by the terminal, the secondary TA according to a TA received in the random access procedure. With the method and the device for obtaining a timing advance according to embodiments of the present invention, a terminal initiates a random access procedure to obtain a secondary timing advance after the terminal receives a secondary cell activation command sent by a base station or after a secondary cell is activated, thereby saving signaling overhead and system resources.