Wireless Mesh Node Listen Rate Dynamics for Latency

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Solution Overview

Problem

In wireless mesh networks, battery-powered device (BPD) nodes face challenges in maintaining network connectivity due to high communication latency and power consumption during the discovery process, especially when they cannot quickly locate a nearby mains powered device (MPD) node, leading to authentication failures and repeated discovery processes.

Innovation Solution

Implementing a method to increase the listen rate of nodes within the wireless mesh network by transmitting packets to intermediate nodes to reduce latency, allowing BPD nodes to complete authentication procedures within a limited time window and preventing unnecessary discovery processes when network access is temporarily lost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If BPD nodes use daisy-chaining to reach upstream MPD nodes, then network access is enabled for distant nodes, but authentication latency increases causing authentication failures

Engineering Contradiction:

Improvenetwork access capabilityVSAvoidauthentication latency

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent applies dynamics by enabling intermediate BPD nodes to dynamically adjust their listen rates based on authentication needs. During authentication, nodes can increase listen rates to reduce latency, then return to normal rates afterward, making the system adaptable to different operational requirements

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the listen rate parameter dynamically. Intermediate nodes receive listen rate change indications from child nodes during authentication and adjust their own listen rates accordingly, transforming the fixed parameter into a variable that adapts to authentication timing requirements

Inventive Principle:

Principle #35Parameter changes

2Reliability

If BPD nodes repeat discovery process after authentication failure, then network access is regained, but battery life decreases

Engineering Contradiction:

Improvenetwork accessVSAvoidbattery life

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements beforehand cushioning by having parent nodes retain child nodes during temporary network access losses. Instead of immediately terminating connections when upstream connectivity fails, parent nodes maintain downstream connections for a predetermined period, cushioning against the need for immediate re-discovery and thus conserving battery life

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Device complexity

If parent nodes immediately terminate child connections when network access is lost, then resource cleanup is simplified, but child nodes must repeat discovery process consuming power

Engineering Contradiction:

Improveconnection managementVSAvoiddiscovery process power consumption

Core Design Contradiction:

Device complexityVSUse of energy by moving object

Solution Approach 1:

The patent applies beforehand cushioning by implementing a retention period during which parent nodes maintain connections to child nodes even when upstream network access is lost. This predetermined retention time cushions against immediate connection termination, allowing children to avoid repeated discovery processes and conserve battery power

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

4Use of energy by moving object

If BPD nodes operate at standard listen rates, then power consumption is minimized, but communication latency increases

Engineering Contradiction:

Improvepower consumptionVSAvoidcommunication latency

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The patent applies dynamics by making the listen rate adjustable rather than fixed. Nodes can dynamically increase listen rates when low latency is required (such as during authentication) and return to standard rates afterward, optimizing the trade-off between power consumption and latency based on actual needs

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the listen rate parameter from a static value to a dynamic one that can be adjusted based on operational requirements. Intermediate nodes modify their listen rates in response to authentication needs, transforming the parameter into a flexible control mechanism that balances power consumption and communication latency

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS10763992B2Techniques for maintaining network connectivity in wireless mesh networks

Publication Date: 2020.09.01 ITRON INC

AI summary

A wireless mesh network includes a plurality of nodes coupled together in parent-child relationships. A child node is configured to cascade listening rate changes upstream to a parent node to perform low-latency communications. The child node transmits an authentication message to the parent node indicating the listening rate change. The child node sets a timer and waits for an acknowledgement from the parent node. If the child node receives the acknowledgement, then the child node and the parent node change listening rate to permit low-latency communications. In addition, if the parent node loses network access, the parent node sets a timer and then waits to abandon the child node until after the timer elapses.