Frequency Hopping Mesh Network Synchronization via Pseudorandom Timing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Frequency hopping spread spectrum (FHSS) synchronization in battery-powered mesh networks is inefficient due to high power consumption and vulnerability to interception, as existing methods require prolonged active periods for device synchronization, which shortens battery life and makes it difficult to secure data transmission.

Innovation Solution

Implementing a mesh network with timing units synchronized to operate in a pseudorandom time interval, allowing devices to switch between transmit, receive, and inactive modes according to a frequency hopping sequence, reducing active periods and enhancing security by making it harder for hackers to intercept signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If devices cycle through all frequency channels to synchronize with FHSS transmission, then synchronization reliability is improved, but power consumption increases significantly

Engineering Contradiction:
Improvesynchronization reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The transmitting device sends synchronization information in advance during its active period, including its identity and the sequence of frequency channels it will use. The receiving device obtains this information beforehand and can directly jump to the correct frequency channel for reception, eliminating the need to cycle through all channels and significantly reducing the receiving device's active time and power consumption.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces a timing synchronization mechanism as an intermediary between transmission and reception. By establishing a common timing reference and using predetermined time intervals for transmission and reception activities, the system enables receiving devices to know exactly when and on which frequency channel to listen, avoiding exhaustive channel scanning and reducing power consumption while maintaining reliable synchronization.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If devices remain in active state for extended periods to ensure reception, then communication reliability is improved, but battery life deteriorates

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidbattery life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The system implements periodic transmission and reception activities based on predetermined time intervals. The transmitting device activates at specific intervals to send data and synchronization information, while receiving devices activate at corresponding intervals to receive transmissions. This periodic operation allows devices to remain in low-power sleep mode between activities, significantly extending battery life while maintaining reliable communication through regular periodic exchanges.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

Synchronization information is transmitted in advance during the transmitting device's active period, enabling receiving devices to prepare and activate only when needed. This preliminary provision of synchronization data allows receiving devices to minimize their active time to exactly what is necessary for reception, avoiding prolonged active states and extending battery life while ensuring communication reliability.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If frequency hopping sequence is predictable, then synchronization ease is improved, but security deteriorates due to interception vulnerability

Engineering Contradiction:
Improvesynchronization easeVSAvoidinterception vulnerability
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The system uses a pseudorandom sequence for frequency hopping that changes over time. While the sequence follows a deterministic pattern based on an initial seed value (making it synchronizable), the actual frequency channels jumped appear random and unpredictable to outsiders. The transmitting and receiving devices share the same pseudorandom sequence generator and initial seed, enabling them to synchronize easily while the changing parameters provide security against interception and jamming.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3560246B1Frequency hopping spread spectrum communication in mesh networks
Publication Date: 2021.11.24 TEXECOM LTD
  • EP3560246B1 patent drawingFigure 1
  • EP3560246B1 patent drawingFigure 2
  • EP3560246B1 patent drawingFigure 3

AI summary

A mesh network comprises a controller and a plurality of mesh-networked devices, operable to communicate with the controller. The controller and the plurality of mesh- networked devices comprise timing units, and are operable to communicate in accordance with a frequency hopping sequence. The mesh-networked devices switch between a transmit mode, in which they are capable of transmitting messages to one or more other mesh-networked device and/or the controller and an inactive mode, in which they are unable to transmit to or receive messages from one or more other mesh- networked devices or the controller. The timing units of the mesh-networked devices are synchronised and the mesh-networked devices are operable to switch to the transmit mode at pseudorandom time intervals.