UE NR Early Measurement Configuration After Cell Reselection
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Solution Overview
Problem
In wireless communication networks, UEs face challenges in determining the synchronization timing reference for SMTC information during early measurements after cell reselection, especially when moving to cells other than the original PCell, leading to inefficiencies in IDLE state inter-frequency measurements.
Innovation Solution
The UE is provided with a new radio early measurement configuration that includes SMTC information based on the timing reference of the target cell, allowing it to determine synchronization and perform accurate measurements even when changing cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE uses SMTC timing reference from the original PCell after cell reselection, then the early measurement configuration can be maintained, but the timing reference becomes inaccurate when moving to non-synchronized cells
Solution Approach 1:
The target cell broadcasts SMTC timing information in advance in its SIB1 message, allowing the UE to obtain the correct timing reference before performing measurements. This preliminary provision of timing information resolves the contradiction by ensuring accuracy is established upfront rather than relying on outdated PCell timing.
Solution Approach 2:
The SIB1 message of the target cell acts as an intermediary that carries SMTC timing information, bridging the gap between cell reselection and accurate timing reference establishment. This intermediary provides the necessary timing data without requiring direct synchronization with the original PCell.
2Device complexity
If the UE stops IDLE state inter-frequency measurements after cell reselection due to missing frequency configuration, then measurement complexity is reduced, but measurement capability is lost
Solution Approach 1:
The SIB1 message serves multiple functions: it provides both cell reselection parameters and SMTC timing information for early measurements. This multi-functionality ensures that measurement capability is maintained without increasing overall system complexity, as the same broadcast message fulfills multiple purposes.
Solution Approach 2:
The target cell autonomously provides the necessary SMTC timing information in its SIB1 broadcast, enabling the UE to self-configure measurements without requiring additional dedicated signaling or complex UE-side configuration processing.
3Measurement precision
If the UE re-acquires SMTC timing from target cell SIB after cell reselection, then timing accuracy is improved, but measurement delay increases
Solution Approach 1:
The target cell prepares and broadcasts SMTC timing information in SIB1 in advance, so the UE can immediately use this information upon cell reselection without requiring additional acquisition time. This preliminary preparation eliminates the time penalty while maintaining accuracy.
Data Source
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AI summary
This disclosure provides systems, methods, and apparatus, including computer programs encoded on computer storage media, for wireless communication by a user equipment (UE). In one aspect, the UE is configured to select, by a user equipment (UE), a list of synchronization signal block (SSB) frequencies included in at least one message as a selected list of SSB frequencies. The UE is further configured to determine, based on whether a first frequency included in the selected list of SSB frequencies is an overlapping carrier or a non-overlapping carrier, whether to perform a new radio (NR) early measurement operation for the first frequency. The UE is also configured to identify a SSB-based measurement timing configuration (SMTC) based on a determination to perform the NR early measurement operation for the first frequency, and to initiate the NR early measurement operation for the first frequency using the identified SMTC.