Split Bearer Architecture for LTE Dual Connectivity Latency

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Solution Overview

Problem

Current LTE dual connectivity architectures face limitations in providing improved multiple connectivity to terminal devices via multiple RAN entities, particularly in managing user plane configurations and avoiding data interruptions when links become unreliable.

Innovation Solution

The method involves triggering a second RAN entity to set up a split bearer with a first bearer leg through a first RAN entity and a second bearer leg directly to the terminal device, using proprietary signaling and user plane encryption keys, allowing the second RAN entity to handle user plane operations independently without going through the first RAN entity, which serves as the control plane anchor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional MCG/SCG bearer configuration is used in LTE dual connectivity, then the control plane anchor (MeNB) must route all user plane data through itself, but this increases data transmission latency and reduces connectivity efficiency when the link through MeNB is unreliable

Engineering Contradiction:
Improveconnectivity reliabilityVSAvoiddata transmission latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the bearer configuration into two independent parts: control plane functions remain anchored at MeNB while user plane functions are directly anchored at SeNB. This segmentation allows the user plane to operate independently without being constrained by the control plane anchor, reducing latency and improving reliability by eliminating the mandatory routing through MeNB.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a new dimension in the bearer architecture by creating a direct user plane path between SeNB and UE that bypasses the traditional MeNB routing dimension. This dimensional change enables parallel operation of control plane (through MeNB) and user plane (direct through SeNB), resolving the contradiction between reliability and latency.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If the link between terminal device and RAN entity becomes unreliable, then path switching in the core network is required to maintain connectivity, but this causes data interruptions during the switching process

Engineering Contradiction:
Improveconnectivity maintenanceVSAvoiddata interruption duration
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent performs preliminary action by pre-configuring the user plane bearer directly at SeNB before any link failure occurs. When the control plane link becomes unreliable, the user plane can immediately switch to the pre-established direct path without requiring core network path switching, thereby maintaining connectivity without data interruptions.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces SeNB as an intermediary that can independently handle user plane data transmission. This intermediary capability allows the system to bypass the problematic MeNB-UE control plane path while maintaining user plane connectivity through the direct SeNB-UE bearer, avoiding data interruptions during failover.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If a third user plane configuration (SeNB split bearer) is introduced to improve connectivity, then user plane management flexibility increases, but the complexity of bearer configuration and management increases

Engineering Contradiction:
Improveuser plane configuration flexibilityVSAvoidbearer configuration complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic bearer configuration where the system can adaptively select between traditional MCG/SCG bearers and the new SeNB split bearers based on real-time network conditions. This dynamic approach provides configuration flexibility while managing complexity through automated selection algorithms that choose the optimal bearer type without requiring manual intervention.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the key parameter of bearer anchoring point from always MeNB to either MeNB or SeNB based on network conditions. This parameter change enables flexible user plane management by allowing the system to switch the user plane anchor location, providing adaptability while keeping the configuration mechanism manageable through standardized parameter adjustments.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3527035B1Methods and apparatuses for providing multiple radio access network connectivity to terminal device
Publication Date: 2021.08.25 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3527035B1 patent drawingFigure 1
  • EP3527035B1 patent drawingFigure 2A
  • EP3527035B1 patent drawingFigure 2B

AI summary

A technique for providing multiple connectivity to a terminal device by at least a first Radio Access Network, RAN entity and a second RAN entity is disclosed. The first RAN entity serves as a control plane anchor and the split bearer will be anchored at the second RAN entity. The method comprises triggering, by the first RAN entity, the second RAN entity to set up the split bearer on the user plane. The split bearer comprises at least a first bearer leg from the second RAN entity via the first RAN entity to the terminal device and a second bearer leg from the second RAN entity to the terminal device without going through the first RAN entity.