Wireless Alarm Controller with Adaptive Message Repetition

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Solution Overview

Problem

Fire alarm systems face challenges in wireless communication due to signal attenuation by building materials and structures, leading to insufficient RF range and potential message interference, which existing solutions like repeaters and master-slave configurations are costly or complex to implement.

Innovation Solution

An alarm device with a controller that manages message repetition based on a repetition level indicator, timing, and serial number order to optimize wireless communication, using a repeater protocol that ensures messages are propagated effectively without excessive repetition or interference, and includes a house coding phase for device identification and signal strength broadcasting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If repeaters and central computer server are used to extend RF range, then wireless communication reliability is improved, but system cost increases

Engineering Contradiction:
Improvewireless communication reliabilityVSAvoidsystem cost
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The alarm devices automatically perform house coding to learn each other's codes and serial numbers during installation, eliminating the need for separate programming equipment. The system self-configures by having devices transmit and learn codes autonomously, reducing installation complexity and cost while maintaining communication reliability.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system dynamically adjusts message repetition based on repetition level indicators. Messages are repeated a maximum of three times with deferred transmission timing based on device serial numbers, creating an adaptive communication protocol that optimizes reliability without requiring additional hardware infrastructure.

Inventive Principle:
Principle #15Dynamics

2Stability of the object's composition

If master-slave categories are defined for alarm devices, then system organization is improved, but setup complexity increases

Engineering Contradiction:
Improvesystem organizationVSAvoidsetup complexity
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

All alarm devices are treated as equal peers in the system rather than dividing them into master-slave categories. Each device has the same capability to transmit, receive, and repeat messages, eliminating the need for complex hierarchical configuration while maintaining stable system organization through symmetric peer-to-peer communication.

Inventive Principle:
Principle #33Homogeneity

3Length of stationary object

If message repetition is increased to overcome signal attenuation, then communication range is improved, but signal interference increases

Engineering Contradiction:
Improvecommunication rangeVSAvoidsignal interference
Core Design Contradiction:
Length of stationary objectVSObject-generated harmful factors

Solution Approach 1:

The system implements periodic message repetition with deferred transmission timing. Messages are repeated at scheduled intervals with delays based on device serial numbers, creating a structured periodic communication pattern that extends effective range while preventing signal clashes through time-division multiplexing.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system maintains continuous communication coverage by repeating messages up to three times with deferred transmission. This continuous action ensures that at least one message copy reaches the destination even when signal attenuation occurs, while the controlled repetition limit prevents excessive interference.

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP1903523B1Alarm systems
Publication Date: 2008.12.31 E I TECHNOLOGY LTD
  • EP1903523B1 patent drawingFigure 1
  • EP1903523B1 patent drawingFigure 2
  • EP1903523B1 patent drawingFigure 3

AI summary

An alarm device comprises an RF receiver, an RF transmitter, and a controller which acts as a repeater. The controller directs repeating of received messages according to repetition level in a repeated message, it reads repetition levels in received messages, and it decides on repeating received messages according to the repetition levels. It does not repeat a message which has already been repeated a maximum threshold number of times, in one embodiment three times. The controller is adapted to time out and re-sets cycles of monitoring repetition levels, and to cancel messages which are held without being repeated for a maximum period of time. Also, the controller performs house coding by in a first phase transmitting and re-transmitting its coding message, and in a second phase repeating house codes it has learned.