PSCell Parameter Retention for Low-Latency SCG Dormancy Reporting

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Solution Overview

Problem

In wireless communication systems, particularly in 5G NR, the latency and synchronization issues with physical layer measurements during secondary cell group (SCG) dormancy lead to reduced effectiveness of measurement reporting, especially when the master node (MN) and secondary node (SN) are not synchronized, and existing methods for reporting measurements introduce additional latency.

Innovation Solution

The UE maintains a parameter set for the primary serving cell (PSCell) while in a dormant state with respect to the SCG, allowing it to transmit physical layer measurements to the secondary node (SN) based on parameter change messages, reducing latency and ensuring the SCG link is not lost during dormancy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the UE releases the parameter set for PSCell during SCG dormancy to reduce power consumption, then power consumption is reduced, but latency increases when resuming communications

Engineering Contradiction:

Improvepower consumptionVSAvoidlatency

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The UE selectively maintains or releases parameter sets based on the specific cell group state. For SCG dormancy, the parameter set for PSCell is maintained locally while other parameters may be released, achieving localized optimization that balances power consumption and latency requirements.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The UE maintains the parameter set for PSCell in advance during SCG dormancy before actual communication resumption is needed. This preliminary retention of parameters ensures that when communication needs to resume, the UE can immediately use the maintained parameters without additional signaling, thus reducing latency while still allowing power savings compared to full active state.

Inventive Principle:

Principle #10Preliminary action

2Use of energy by moving object

If the UE releases the SCG link during dormancy to save power, then power consumption is reduced, but synchronization is lost leading to measurement latency

Engineering Contradiction:

Improvepower consumptionVSAvoidsynchronization

Core Design Contradiction:

Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The UE maintains the SCG link specifically for PSCell in a dormant state while potentially releasing other SCG links. This selective maintenance preserves synchronization and measurement capabilities for the primary serving cell while still achieving power consumption reduction compared to maintaining all SCG links fully active.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The UE maintains the SCG link for PSCell in a dormant state continuously, allowing measurement reporting to continue without interruption. This continuous maintenance of the link ensures synchronization is preserved and measurement precision is maintained, while the dormant state still provides power savings compared to full active communication.

Inventive Principle:

Principle #20Continuity of useful action

3Measurement precision

If additional signaling is used to update parameters during dormancy, then measurement accuracy is improved, but power consumption and latency increase

Engineering Contradiction:

Improvemeasurement accuracyVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The parameter set for PSCell is maintained in advance during dormancy without requiring additional signaling updates. This preliminary retention of accurate parameters ensures measurement accuracy is preserved while avoiding the power consumption and latency overhead of continuous signaling exchanges during the dormant period.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The UE uses the maintained parameter set autonomously during dormancy for measurement reporting without requiring external signaling updates. This self-service approach allows the UE to continue accurate measurements using existing parameters, eliminating the need for additional signaling that would increase power consumption and latency.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS12489582B2User equipment (UE) physical layer measurement reporting in secondary cell group (SCG) dormancy

Publication Date: 2025.12.02 QUALCOMM INC

AI summary

This disclosure provides systems, methods and apparatus, including computer programs encoded on computer storage media, for a user equipment (UE) entering a dormant state with respect to a secondary cell group (SCG) of a node network (SN) having a primary serving cell (PSCell). In one aspect, the UE may maintain a parameter set for at least the PSCell while the UE is in the dormant state with respect to the SCG. For example, the UE may receive a parameter change message from either the SN or a master network (MN) and transmit a parameter change acknowledgment to either the SN or the MN. The parameter change message may be transmitted as one or both of a downlink control information (DCI) or media access control (MAC) control element (CE). The UE may transmit physical layer measurements to the SN based on the parameter set.