RRC Inactive Paging Handling for Multicast and SDT Conflicts

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Solution Overview

Problem

In wireless communication systems, terminal devices in RRC inactive state may fail to enter the RRC connected state upon receiving a multicast activation notification, leading to missed multicast services due to conflicts with SDT transmission paging.

Innovation Solution

A communication method that allows terminal devices to determine conditions under which they can receive multicast services without entering the RRC connected state, by initiating RRC connection resume using specific criteria, such as presence of multicast paging or activation notifications, and selecting appropriate resources for connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the terminal device enters RRC connected state to receive multicast service, then the multicast service can be received, but the SDT transmission may be interrupted or delayed

Engineering Contradiction:
Improvemulticast service receptionVSAvoidSDT transmission time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The solution segments the paging message into two distinct types: multicast activation paging and SDT paging. The terminal device can identify the paging type through specific indicators in the message, allowing it to process only the relevant paging without being forced to enter RRC connected state for unrelated purposes. This segmentation resolves the contradiction by separating the multicast service reception path from the SDT transmission path.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The terminal device dynamically adjusts its RRC state transition behavior based on the paging message content. When receiving multicast activation paging, it transitions to RRC connected state. When receiving SDT paging, it remains in RRC inactive state and performs SDT procedures. This dynamic adaptation allows the system to optimize state transitions based on actual service requirements, preventing unnecessary state changes that would interrupt SDT transmission.

Inventive Principle:
Principle #15Dynamics

2Loss of time

If the terminal device remains in RRC inactive state to maintain SDT transmission, then SDT transmission continues uninterrupted, but the terminal device cannot receive multicast service activation notification

Engineering Contradiction:
ImproveSDT transmission continuityVSAvoidmulticast service reception
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The paging message acts as an intermediary that carries dual functionality. It can simultaneously indicate both SDT opportunities and multicast service activation notifications through different indicators within the same message structure. This allows the terminal device to remain in RRC inactive state while still receiving both types of information, eliminating the need to choose between SDT continuity and multicast service reception.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The paging message is designed with multi-functionality to serve both SDT and multicast service purposes. By incorporating universal indicators that can represent different service types within a single message framework, the system allows the terminal device to process multiple service types without transitioning RRC states unnecessarily, thus maintaining SDT continuity while enabling multicast service reception.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If the network device sends both multicast activation notification and SDT paging, then both services are notified, but the terminal device cannot process both simultaneously

Engineering Contradiction:
Improveservice notification completenessVSAvoidterminal device processing complexity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The paging message incorporates local quality differentiation through specific indicators that mark different service types. The terminal device can locally identify and process only the relevant service indication based on its current state and requirements. This localized processing approach simplifies terminal device operation by allowing it to selectively respond to appropriate paging types without being overwhelmed by dual service notifications.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4686317A1Communication method, apparatus and system
Publication Date: 2026.01.28 HUAWEI TECH CO LTD
  • EP4686317A1 patent drawingFigure 1~2A
  • EP4686317A1 patent drawingFigure 2B
  • EP4686317A1 patent drawingFigure 3A~3B

AI summary

Embodiments of this application provide a communication method, apparatus, and system, and relate to the field of communication technologies. The method is used to ensure that receiving of a multicast service is not affected when a paging of SDT transmission conflicts with a paging of the multicast service. The method includes: A terminal apparatus receives a first paging message. When a first condition and a second condition are satisfied, the terminal apparatus initiates radio resource control RRC connection resume associated with not entering an RRC connected state. The first condition includes: The first paging message includes a first identifier of the terminal apparatus and first indication information. The first identifier of the terminal apparatus is associated with a radio access network RAN paging. The first indication information indicates MT-SDT information. The second condition includes: The terminal apparatus has not received a multicast paging or a multicast activation notification associated with entering the RRC connected state. The method can resolve a paging conflict problem when the first paging message includes two different types of pagings.