Secondary Cell Group Dormancy Control via DCI Bitmap

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Solution Overview

Problem

In current radio communication systems, indicating dormancy of a secondary cell using DCI configuration fields not for scheduling lacks flexibility, as it is difficult to specify which secondary cell should transition to dormancy.

Innovation Solution

A terminal is equipped with a receiving unit to receive dormancy configuration from a base station through higher layer signaling and control information through the physical layer, and a control unit that transitions secondary cell groups to dormant or non-dormant states based on specific fields in the control information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If dormancy of a secondary cell is indicated by configuring a part of fields of DCI to be not for scheduling, then power saving is achieved, but flexibility to specify which secondary cell should transition to dormancy is lost

Engineering Contradiction:

Improvepower savingVSAvoidflexibility to specify secondary cell

Core Design Contradiction:

Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent segments the secondary cells into groups and assigns bitmap indices to each group. The DCI includes a bitmap field where each bit corresponds to a specific secondary cell group, allowing flexible specification of which groups transition to dormancy. This segmentation enables precise control while maintaining the power saving benefits of DCI-based indication.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a bitmap as an intermediary structure between the DCI and the secondary cells. The bitmap field in DCI serves as a mediator that maps bit positions to secondary cell groups, enabling flexible and efficient indication of dormancy status without requiring complete reconfiguration of DCI fields.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If a bitmap is used to indicate dormancy of secondary cell groups, then flexibility is improved, but the complexity of DCI configuration increases

Engineering Contradiction:

Improveflexibility to specify secondary cell groupVSAvoidDCI configuration complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes the bitmap field in DCI multi-functional by configuring it to serve both as a dormancy indication mechanism and as a flexible specification tool for secondary cell groups. The same bitmap structure used for dormancy indication also enables the base station to dynamically select which specific groups should transition to dormant state, eliminating the need for separate configuration mechanisms.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12342226B2Terminal and communication method

Publication Date: 2025.06.24 NTT DOCOMO INC

AI summary

A terminal includes a receiving unit that receives a configuration on dormancy of one or more secondary cells from a base station through higher layer signaling, and that receives control information including a notification related to dormancy through a physical layer; and a control unit that transitions a secondary cell group configured by the configuration to a dormant state or a non-dormant state on a per secondary cell group basis, based on a specific field included in the control information.