Mesh Path Discovery With Redundant Relay Nodes for Link Failures

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Solution Overview

Problem

Message reliability in single-path directed forwarding algorithms for Bluetooth mesh networks is low due to unstable wireless links and interference, leading to potential failures in message delivery.

Innovation Solution

Assign redundant relay nodes during path discovery by introducing an Extended Path Reply Message (EPREP) that includes both a selected relay node and one or more redundant relay nodes, enhancing path redundancy without creating a separate path.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mesh network is designed to be highly resilient and adaptive, then the network can dynamically route around failures and adapt to changing conditions, but the path discovery procedure becomes excessively complex and computationally intensive

Engineering Contradiction:
Improvenetwork resilienceVSAvoidpath discovery complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the path discovery process into distinct phases: initial path discovery using AODV, followed by redundant path discovery using RAPD when failures are detected. This segmentation allows the system to maintain simplicity for normal operations while enabling complex resilient behavior only when needed, thus resolving the contradiction between reliability and complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary actions by pre-configuring RAPD to stand by and automatically activate when link failures are detected. Rather than continuously maintaining complex redundant routing tables, the system prepares the mechanism in advance and only engages it when necessary, reducing normal operational complexity while ensuring reliability when failures occur.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If redundant relay nodes are added to provide alternative paths, then network reliability improves, but the number of nodes and computational overhead increase

Engineering Contradiction:
Improvepath redundancyVSAvoidnumber of nodes
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent implements dynamic node selection where relay nodes are not permanently assigned but temporarily activated based on real-time network conditions. When link failures occur, RAPD dynamically identifies and activates alternative relay nodes from the existing mesh network, providing path redundancy without permanently increasing the number of dedicated relay nodes or their associated overhead.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameters of existing nodes rather than adding new infrastructure. By modifying how existing mesh nodes participate in routing (activating them as relay nodes only when needed), the system achieves path redundancy without permanently increasing the quantity of nodes or their computational overhead, thus resolving the contradiction between reliability and node quantity.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If traditional AODV protocol is used for path discovery, then the implementation is simple and lightweight, but the protocol lacks mechanisms to handle link failures and maintain continuous connectivity

Engineering Contradiction:
Improveimplementation simplicityVSAvoidfailure handling capability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent introduces RAPD as an intermediary layer that works alongside AODV. Rather than replacing the simple AODV protocol, RAPD acts as a mediator that activates only when link failures occur, providing enhanced failure handling capability while preserving the implementation simplicity of AODV for normal operations. This intermediary approach resolves the contradiction between simplicity and reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3854039B1A method for adding redundant relay nodes during path discovery procedure of a mesh network
Publication Date: 2026.05.06 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3854039B1 patent drawingFigure 1
  • EP3854039B1 patent drawingFigure 2a
  • EP3854039B1 patent drawingFigure 2b

AI summary

A method and apparatus for device establishing redundant relay nodes in a mesh network.