Mobile Wireless Data Transfer with LTM Cell Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems face challenges in minimizing service interruption and latency during cell switching, particularly in 5G networks, due to the reliance on L3 measurements and RRC signaling for serving cell changes, which incur significant overhead and delay.
Innovation Solution
Implementing Layer 1/Layer 2 Triggered Mobility (LTM) procedures, where a base station sends L1 measurement reports to a UE, allowing for efficient cell switching through MAC CE commands, and optimizing data transfer by discarding and retransmitting specific radio bearers with ROHC protocol resets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If L3 measurements and RRC signaling are used for serving cell change, then configuration reliability is improved, but service interruption time and latency increase
Solution Approach 1:
The patent segments the radio bearers into first set (signaling bearers) and second set (data bearers), applying different handling strategies to each. Signaling bearers undergo complete reset for reliability, while data bearers maintain state for continuity, resolving the contradiction between reliability and interruption time
Solution Approach 2:
The patent performs preliminary actions by discarding PDCP SDUs/PDCP PDUs before the actual cell switch occurs, and by maintaining ROHC context information in advance. This preparation enables faster transition and reduces service interruption time while maintaining configuration reliability
2Manufacturing precision
If complete L2 reset is performed for cell switch, then configuration accuracy is improved, but data transfer efficiency deteriorates
Solution Approach 1:
The patent segments the reset operation by applying complete L2 reset only to signaling radio bearers (first set) while maintaining context for data radio bearers (second set). This selective approach ensures configuration accuracy for signaling while preserving data transfer efficiency
Solution Approach 2:
The patent discards PDCP SDUs/PDCP PDUs for signaling bearers to ensure clean configuration, while recovering and maintaining ROHC context information for data bearers. This selective discarding and recovering mechanism resolves the contradiction between configuration accuracy and data transfer efficiency
3Reliability
If L3 triggered reconfiguration is used, then protocol compliance is improved, but overhead and latency increase
Solution Approach 1:
The patent replaces L3 triggered reconfiguration mechanism with L2 triggered reconfiguration using MAC CE commands. This substitution reduces protocol overhead and latency while maintaining compliance through standardized MAC layer procedures
Solution Approach 2:
The patent performs preliminary configuration of radio bearers before the actual switch occurs, allowing the UE to prepare necessary parameters in advance. This preliminary action reduces the overhead and latency associated with L3 triggered reconfiguration while maintaining protocol compliance
Data Source
AI summary
A method to enable efficient data transfer for cell switch in conjunction with LTM operation is provided. The method of the terminal includes receiving from a base station a RRC reconfiguration message, receiving from the base station a specific MAC PDU that contains the first identifier of a specific configuration, discarding for a first set of radio bearers all stored PDCP SDUs and PDCP PDUs, and performing for a second set of radio bearers transmission of PDCP SDUs after reset of ROHC protocol. The first set of radio bearers comprises specific signaling radio bearers and the second set of radio bearers comprises specific data radio bearers.