MTC Terminal System Information Update Mechanism
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Solution Overview
Problem
In LTE systems, changing system information is time-consuming, especially for MTC terminals using repetitious transmission for coverage enhancement, as they need to acquire and update all system information from SIB1, which can lead to inadequate communication if the process takes too long.
Innovation Solution
A user terminal and radio base station system that allows MTC terminals to change only a part of the system information based on the content of the modification, by including information related to the content of the modification in the modification order, enabling quicker updates and maintaining adequate communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If MTC terminals use repetitious transmission for coverage enhancement, then coverage is improved, but system information update time increases
Solution Approach 1:
The system information is segmented into multiple SIBs (System Information Blocks), each containing specific types of information. The network can indicate which specific SIBs have been modified, allowing terminals to update only those segments rather than reacquiring all system information, thus reducing update time while maintaining coverage enhancement benefits
Solution Approach 2:
The network performs preliminary action by broadcasting modification indicators (such as systemInfoModification in paging messages) before the actual system information change. This allows MTC terminals to be notified in advance and selectively acquire only the modified SIBs, rather than performing full system information acquisition, thereby reducing update time while maintaining coverage enhancement
2Loss of information
If MTC terminals acquire all system information from SIB1, then system information completeness is ensured, but update time increases
Solution Approach 1:
The invention extracts and isolates the modification indicator information from the complete system information acquisition process. By taking out the modification indication (which SIBs have changed) as a separate element, the terminal can selectively acquire only the necessary SIBs rather than all system information, ensuring completeness of updated information while reducing update time
Solution Approach 2:
The network provides feedback information (modification indicators) that tells terminals which specific system information has changed. This feedback mechanism allows terminals to make informed decisions about what information to acquire, ensuring they get all necessary updates without unnecessarily acquiring unchanged information, thus balancing completeness with efficiency
Data Source
AI summary
The present invention is designed so that adequate communication is allowed even when system information is changed. The present invention provides a receiving section that receives a DL signal, which includes information that orders a modification of system information, and a control section that controls the modification of the system information based on the DL signal, and, when information related to content of the modification of the system information is included in the information ordering the modification, the control section changes a part or all of the system information based on the information related to the content of the modification. Also, in the modification order information, information to indicate that the system information is not changed and information to indicate the content of the modification when the system information is changed are defined as different pieces of bit information in the same bit field.