Wireless Fire System Output Synchronization via TDMA
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fire detection systems with wireless transceivers often experience synchronization issues and delays, leading to unsynchronized activation of warning devices, which can result in unacceptable behaviors and safety concerns.
Innovation Solution
A mesh network communication protocol with a parent-child relationship and time division multiple access (TDMA) format is used, where nodes transmit data in a predetermined slot order, allowing for efficient data aggregation and synchronization of warning devices through an output synchronization message that adjusts for time delays across the network.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If wireless transceivers are used to reduce installation costs, then installation cost is reduced, but synchronization of warning devices deteriorates due to message latency and delays
Solution Approach 1:
The system pre-calculates and stores transmission delays for each node before actual warning device activation. When a fire alarm is triggered, the control panel retrieves pre-computed delay values and sends synchronization commands that account for these delays in advance, ensuring all warning devices activate simultaneously despite varying wireless transmission times.
Solution Approach 2:
The system dynamically adjusts transmission parameters including message timing and delay compensation values based on calculated transmission characteristics. By modifying the timing parameters of synchronization commands and incorporating delay compensation, the system maintains synchronized warning device activation while using cost-effective wireless transceivers.
2Loss of time
If mesh network with parent-child relationships and TDMA is used, then message latency is reduced and synchronization is improved, but device complexity increases
Solution Approach 1:
The mesh network is organized into hierarchical parent-child relationships that segment the communication structure. This segmentation allows systematic assignment of transmission slots in TDMA format, reducing message latency by establishing predictable communication paths while managing complexity through structured organization rather than arbitrary node connections.
Solution Approach 2:
The system implements periodic transmission slots in TDMA format where each node has predetermined time windows for communication. This periodic structure reduces message latency by eliminating random access delays and collisions, while the regular pattern simplifies protocol implementation compared to ad-hoc scheduling approaches.
3Adaptability or versatility
If wireless transceivers with mesh networking are implemented, then installation flexibility is improved, but warning device synchronization deteriorates due to delays and collisions
Solution Approach 1:
The system performs preliminary calculation of transmission delays for each node during network setup or calibration phase. These pre-computed delay values are stored and used to generate synchronization commands that compensate for individual node delays, ensuring synchronized warning device activation while maintaining the flexibility of wireless mesh networking.
Solution Approach 2:
The system incorporates feedback mechanisms where nodes report their actual transmission timing and delay experiences back to the control panel. This feedback enables the control panel to refine delay compensation values and adjust synchronization commands, maintaining reliable warning device synchronization while preserving installation flexibility of the wireless mesh network.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A method and apparatus that including a control panel sending an activate output command, a gateway of the control panel receiving the activate output command and determining a time period until a wireless communication subsystem becomes available, the wireless subsystem adjusting the determined time period by determining a time until a node is available to receive the output command through the gateway and wireless subsystem, the wireless subsystem sending the output command and a value of the adjusted determined time period to the node and the node activating an output device based upon the output command and adjusted determined time period.