Network-Driven RRC Re-Establishment for Control Plane Failures

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Solution Overview

Problem

The RRC re-establishment procedure in 5G NR systems, particularly in cloud infrastructure deployments, often results in significant user plane service interruptions due to the unavailability of control plane functions, failing to meet the stringent latency and reliability requirements of Ultra Reliable Low Latency Communication (URLLC) services.

Innovation Solution

A network-driven RRC re-establishment procedure is introduced, allowing for control plane synchronization between the UE and the network without affecting user plane data radio bearers, by initiating a control-plane only re-establishment when the control plane function fails, using a network-initiated mechanism to maintain context synchronization and minimize service disruptions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional RRC re-establishment procedure is performed when control plane function fails, then control plane connection is restored, but user plane service experiences significant interruption

Engineering Contradiction:

Improvecontrol plane connection reliabilityVSAvoiduser plane service interruption time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the re-establishment procedure into control plane only operations, separating it from user plane data transmission. This allows the control plane to be re-established independently without forcing a complete suspension of user plane services, thereby reducing service interruption time while maintaining control plane reliability

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary mechanism where the network node can independently synchronize control plane context with the UE without requiring full RRC re-establishment. This intermediary approach allows selective updates of control plane parameters while maintaining active user plane connections, minimizing service disruption

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If cloud infrastructure is used to support 5G Core Network and RAN functionality, then deployment flexibility and cost are improved, but hardware availability and reliability decrease

Engineering Contradiction:

Improvedeployment flexibilityVSAvoidhardware availability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent implements prior cushioning by enabling the network node to detect control plane function unavailability in advance and trigger a targeted re-establishment procedure. This preparedness mechanism allows the system to handle cloud infrastructure failures proactively, maintaining service continuity despite the lower hardware reliability inherent in cloud deployments

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If full RRC re-establishment is performed to restore control plane connection, then connection reliability is improved, but user plane data transmission is interrupted

Engineering Contradiction:

Improvecontrol plane connection reliabilityVSAvoiduser plane data transmission continuity

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent segments the re-establishment process to affect only control plane functions while preserving user plane data bearers. This selective approach allows control plane reliability to be restored without interrupting user plane productivity, as the user plane connections remain active throughout the control plane re-establishment procedure

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by performing only the necessary control plane re-establishment steps rather than a complete RRC re-establishment. This partial approach restores control plane reliability while avoiding the excessive action of suspending user plane services, thereby maintaining data transmission continuity

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS12520364B2RRC re-establishment

Publication Date: 2026.01.06 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

Methods and apparatus are provided. In an example aspect, a method in a User Equipment (UE) of performing a RRC re-establishment procedure is provided. The method comprises receiving an instruction from a network node to perform a RRC re-establishment procedure, and transmitting a RRC re-establishment request.