RRC Resume Multicast Configuration Across Cell Reselection

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Solution Overview

Problem

Terminal devices in RRC inactive state experience difficulties in correctly receiving multicast services after multiple cell reselections due to inconsistent multicast configuration information across different serving cells, leading to interruptions and increased power consumption.

Innovation Solution

The terminal device stores multicast configuration information from the last serving cell and uses it to resume the RRC connected state, ensuring consistent multicast reception by sending an RRC resume request message and receiving the RRC resume message with pre-stored configuration, thereby reducing interruptions and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the terminal device obtains multicast configuration information from MCCH messages of different serving cells after multiple cell reselections, then the terminal device can receive multicasts in different serving cells, but the multicast configuration information includes different MRB configurations causing inconsistency and reception failure

Engineering Contradiction:

Improvemulticast reception capabilityVSAvoidmulticast reception accuracy

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The terminal device stores the MRB configuration from the anchor base station before cell reselection. When resuming the RRC connected state, the terminal device restores this pre-stored MRB configuration to ensure consistency with the network side, preventing configuration mismatch and multicast reception failure.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The terminal device copies the MRB configuration information from the anchor base station and stores it locally. This copied configuration is then restored after cell reselection to replace the inconsistent configuration obtained from MCCH messages of different serving cells, ensuring configuration consistency.

Inventive Principle:

Principle #26Copying

2Ease of operation

If the terminal device performs multiple cell reselections in RRC inactive state, then the terminal device can maintain connection to different serving cells, but the terminal device cannot restore the original MRB configuration causing multicast reception interruption

Engineering Contradiction:

Improvecell reselection flexibilityVSAvoidmulticast reception interruption time

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The terminal device performs preliminary storage of the MRB configuration before cell reselection occurs. This pre-stored configuration enables quick restoration after reselection without requiring time-consuming reconfiguration procedures, thereby reducing multicast reception interruption time.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If the terminal device restores MRB configuration after cell reselection, then the terminal device can maintain multicast reception, but the terminal device consumes additional power for configuration management and state transitions

Engineering Contradiction:

Improvemulticast reception continuityVSAvoidterminal device power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The terminal device autonomously manages its own MRB configuration by storing it locally and restoring it after cell reselection. This self-service approach eliminates the need for network-side configuration retransmission and complex interaction procedures, reducing power consumption while ensuring configuration consistency.

Inventive Principle:

Principle #25Self-service

4Adaptability or versatility

If the terminal device obtains multicast configuration from serving cells during cell reselection, then the terminal device can adapt to new serving cells, but the configuration information from different cells causes inconsistency with anchor base station

Engineering Contradiction:

Improveserving cell adaptabilityVSAvoidMRB configuration consistency

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The terminal device preliminarily stores the authoritative MRB configuration from the anchor base station before cell reselection. After reselection, this pre-stored configuration is restored to override the inconsistent configuration obtained from new serving cells, maintaining configuration stability and consistency.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The terminal device applies different configuration sources selectively: using the anchor base station's MRB configuration for multicast reception while allowing flexibility in serving cell selection. This local quality approach ensures that the critical MRB configuration remains consistent while maintaining adaptability to different serving cells.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS20260067988A1Communication method and apparatus, and system

Publication Date: 2026.03.05 HUAWEI TECH CO LTD

AI summary

A communication method and apparatus, and a system, to improve efficiency of receiving a multicast service. The communication method includes: sending a radio resource control (RRC) resume request message to a first network device; receiving an RRC resume message sent by the first network device; entering an RRC connected state from an RRC inactive state; and receiving a first multicast based on a first multicast broadcast service radio bearer (MRB), where the first MRB is determined based on the RRC resume message and first multicast configuration information, the first multicast configuration information is obtained from a second network device, and the second network device is a network device in a last serving cell in an RRC connected state.