UE Beam Indicator Lists for Low-Latency Mobility Cell Switching

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current 5G NR systems face challenges in efficiently managing beam switching during mobility events, leading to increased latency and overhead due to the need for RRC reconfigurations, which are not optimized for low-latency and high-reliability scenarios like URLLC and mMTC.

Innovation Solution

The implementation of a user equipment (UE) that receives two lists of beam indicators: one for pre-processing before mobility cell switch and another for post-switch operations, allowing for lower-layer triggered mobility (LTM) without RRC reconfiguration, thereby reducing latency and overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If RRC reconfiguration is used for beam switching during mobility events, then beam management is achieved, but latency and overhead increase

Engineering Contradiction:
Improvebeam management reliabilityVSAvoidcell-switching latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the beam indicator configuration into two separate lists: a first list for pre-processing before mobility cell switch and a second list for post-switch operations. This segmentation allows the UE to perform lower-layer triggered mobility without requiring full RRC reconfiguration, thereby reducing latency while maintaining reliable beam management.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary action by configuring the first list of beam indicators in advance, before the mobility cell switch occurs. The UE can pre-process signals from the target cell using these pre-configured beam indicators, enabling faster cell switching without waiting for RRC reconfiguration after the switch.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If RRC reconfiguration is used for beam switching during mobility events, then beam management is achieved, but overhead increases

Engineering Contradiction:
Improvebeam management reliabilityVSAvoidconfiguration overhead
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent segments the configuration information into two distinct lists of beam indicators with different purposes. The first list is used for pre-processing before mobility, and the second list is used for post-switch operations. This segmentation allows the network to provide targeted configuration information, reducing the overall overhead compared to full RRC reconfiguration while maintaining complete beam management functionality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts only the essential beam indicator configurations needed for mobility operations into separate lists, removing the need for complete RRC reconfiguration. By taking out only the necessary beam management parameters into these dedicated lists, the overhead is significantly reduced while the critical beam management reliability is preserved.

Inventive Principle:
Principle #2Taking out (Extraction)

3Loss of time

If separate lists of beam indicators are provided for pre-processing and post-switch operations, then cell-switching latency is reduced, but configuration complexity increases

Engineering Contradiction:
Improvecell-switching latencyVSAvoidconfiguration structure
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent segments beam indicator configuration into functionally distinct lists to enable lower-layer triggered mobility without RRC reconfiguration. The first list contains beam indicators for pre-processing before cell switch, while the second list contains beam indicators for post-switch operations. This segmentation allows the UE to perform mobility operations with reduced latency by using pre-configured beam indicators from the first list during the transition, while the network manages the complexity of maintaining and updating these separate lists.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4589859A1User equipment and base station involved in configuration procedure
Publication Date: 2025.07.23 PANASONIC INTELLECTUAL PROPERTY CORP OF AMERICA
  • EP4589859A1 patent drawingFigure 1~3
  • EP4589859A1 patent drawingFigure 4~5
  • EP4589859A1 patent drawingFigure 6~7

AI summary

The present disclosure relates to a user equipment comprising the following. A receiver receives configuration information for each of at least one mobility candidate cell, the configuration information configuring: • a first list of one or more beam indicators, the first list being usable by the UE for preprocessing of signals from the respective mobility candidate cell when located in a serving cell of the UE before a mobility cell switch to the respective mobility candidate cell, • a second list of one or more beam indicators, the second list being usable by the UE for one or more of signal transmission and signal reception when located in the respective mobility candidate cell after a mobility cell switch. At least a part of the first list is also usable by the UE for one or more of the signal transmission and signal reception after the mobility cell switch.