Split Multicast Radio Bearers for Reliable 5G/NR Services

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Solution Overview

Problem

Existing 5G/NR multicast and broadcast services lack the capability to provide enhanced services compared to 4G/LTE, necessitating improved communication methods and user equipment to support advanced multicast and broadcast functionalities.

Innovation Solution

A communication method and user equipment are developed to enable enhanced multicast and broadcast services in 5G/NR systems, utilizing techniques such as point-to-point (PTP) and point-to-multipoint (PTM) delivery methods, along with split multicast radio bearers to dynamically switch between transmission modes and enhance reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If 4G/LTE multicast and broadcast services are used, then service compatibility is maintained, but service enhancement capability is limited

Engineering Contradiction:
Improveservice enhancement capabilityVSAvoidservice reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent segments the multicast radio bearer into two independent legs: a PTM leg for efficient group communication and a PTP leg for reliable individual delivery. This segmentation allows the system to leverage both transmission modes simultaneously, achieving service enhancement while maintaining reliability through the PTP backup path.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The split multicast radio bearer structure provides multi-functionality by supporting both PTM and PTP transmission modes within a single bearer framework. This universal structure can adapt to different service requirements, providing enhanced services while maintaining compatibility with existing 4G/LTE multicast and broadcast services.

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

2Productivity

If only PTM delivery method is used, then radio efficiency is improved, but service reliability deteriorates

Engineering Contradiction:
Improveradio efficiencyVSAvoidservice reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent divides the multicast radio bearer into PTM and PTP legs, allowing PTM to handle bulk data transmission for radio efficiency while PTP provides reliable delivery for critical data. This segmentation resolves the contradiction by assigning different functions to each leg based on their strengths.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The PTP leg acts as an intermediary backup mechanism that compensates for the reliability limitations of PTM. When PTM transmission fails or data loss occurs, the PTP leg provides an alternative delivery path, ensuring service reliability while maintaining PTM's radio efficiency for normal operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If only PTP delivery method is used, then service reliability is improved, but radio efficiency deteriorates

Engineering Contradiction:
Improveservice reliabilityVSAvoidradio efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent segments the bearer structure to assign PTM to the data transmission path for high radio efficiency and PTP to the control and backup path for reliability. This segmentation allows each transmission mode to operate in its optimal performance zone.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of using PTP for all transmissions (excessive action that would ensure reliability but reduce efficiency), the patent applies PTM for the majority of data transmissions where efficiency is critical, and uses PTP partially for reliability-critical transmissions and as a backup mechanism.

Inventive Principle:
Principle #16Partial or excessive action

4Adaptability or versatility

If dynamic PTM/PTP switching is implemented, then service adaptability is improved, but device complexity increases

Engineering Contradiction:
Improveservice adaptabilityVSAvoidbearer configuration complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a dynamic split MRB configuration that can adaptively switch between PTM and PTP legs based on service requirements, channel conditions, and network state. This dynamic capability provides service adaptability while the standardized switching mechanism keeps implementation complexity manageable.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4366448B1Communication method
Publication Date: 2025.09.10 KYOCERA CORP
  • EP4366448B1 patent drawingFigure 1
  • EP4366448B1 patent drawingFigure 2
  • EP4366448B1 patent drawingFigure 3

AI summary

In a first aspect, a communication method is used in a mobile communication system for supporting a multicast and broadcast service (MBS). The communication method includes: determining, by a user equipment having started reception of an MBS session from a base station, whether a predetermined condition is satisfied indicating that the reception has started midway of the MBS session; and transmitting, by the user equipment to the base station lost packet identification information indicating a lost packet group from a start of the MBS session until a start of the reception, when determining that the predetermined condition is satisfied.