Split Signaling Radio Bearer for UE Inactive-State Communication

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Solution Overview

Problem

Existing wireless communication systems face challenges in optimizing signaling to and from user equipment (UE) in an inactive network state, particularly in managing signaling radio bearers (SRBs) and security protocols during RNA updates, especially in scenarios involving dual connectivity and mobility of UEs.

Innovation Solution

The proposed solution involves establishing a signaling radio bearer (SRB) with a first link to a first base station and a second link to a second base station, maintaining UE context in the network, and communicating via the SRB while in an inactive state, optimizing SRB usage and security protocols for efficient RNA updates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a UE in inactive state transmits uplink data to a currently serving base station via a radio bearer, then data transmission is enabled, but signaling overhead increases

Engineering Contradiction:
Improvedata transmission capabilityVSAvoidsignaling overhead
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The patent segments the radio bearer into two types: data radio bearers for user data transmission and signaling radio bearers for control signaling. This segmentation allows data transmission in inactive state through data bearers while minimizing signaling overhead by using pre-established signaling bearers for necessary control messages.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent establishes signaling radio bearers and maintains UE context information in advance at the base station before the UE enters inactive state. This preliminary action enables the base station to quickly process uplink data and control signaling without extensive setup procedures, reducing signaling overhead during inactive state operations.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If the network maintains UE context at the base station for inactive state communication, then communication efficiency is improved, but network resource consumption increases

Engineering Contradiction:
Improvecommunication efficiencyVSAvoidnetwork resources
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent applies local quality by maintaining UE context information specifically at the currently serving base station where the UE is actively communicating, rather than distributing it network-wide. This localized context maintenance improves communication efficiency for inactive state operations while consuming minimal network resources, as only the relevant base station holds the context.

Inventive Principle:
Principle #3Local quality

3Reliability

If a split signaling radio bearer with multiple links is established for dual connectivity, then communication reliability is improved, but device complexity increases

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidbearer configuration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the signaling radio bearer into multiple independent links (first link to first base station, second link to second base station) for dual connectivity scenarios. Each link operates independently, providing redundancy and improved reliability. The segmentation allows the UE to maintain communication through alternative links if one fails, while the modular structure manages complexity through clear separation of functions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The split signaling radio bearer design provides multi-functionality by enabling the same signaling bearer structure to serve multiple base stations simultaneously in dual connectivity mode, while also supporting single-base-station scenarios. This universal design approach improves reliability across different deployment scenarios without proportionally increasing complexity, as the underlying bearer mechanisms remain consistent.

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

Data Source

PatentEP3782427B1Split bearer communication with a user equipment in an inactive state
Publication Date: 2025.11.12 QUALCOMM INC
  • EP3782427B1 patent drawingFigure 1
  • EP3782427B1 patent drawingFigure 2
  • EP3782427B1 patent drawingFigure 3

AI summary

Disclosed is a method for wireless communications by a user equipment (UE), comprising: receiving signaling of a configuration to establish a signaling radio bearer (SRB) with at least one of a first link to a first network entity and a second link to a second network entity; transitioning to an inactive state where context of the UE in the network is maintained at the UE and at least the first network entity; and communicating with the network using the SRB while in the inactive state. Further, disclosed is a method for wireless communications by a network entity, comprising: signaling, to a UE, a configuration to establish an SRB with a first link to the network entity and a second link to another network entity; transitioning the UE to an inactive state where context of the UE in the network is maintained at the UE and at least the first network entity; and communicating with the UE via the SRB while the UE is in the inactive state.