Wireless Sensor Time Synchronization Using Dual Clocks

The system dynamically switches between low frequency and high frequency clocks based on operational state. During sleep mode, a low frequency clock maintains basic time tracking with minimal power consumption. When the node wakes up, it switches to a high frequency clock to achieve accurate time synchronization for data transmission and reception, thus adapting the timekeeping mechanism to different operational requirements and resolving the contradiction between continuous accuracy and power savings.

The system employs periodic wake-up cycles where nodes alternate between sleep mode using low frequency clocks and active periods using high frequency clocks. During each wake period, nodes perform time synchronization updates and data exchanges, then return to sleep mode. This periodic switching allows the system to achieve necessary synchronization accuracy only when needed, significantly reducing overall power consumption while maintaining network synchronization.

Instead of continuously synchronizing with the master node, the system performs partial synchronization actions only when necessary. Nodes use low frequency clocks during sleep mode to maintain approximate time tracking, then perform a single high-precision synchronization update upon waking up. This partial action approach provides sufficient synchronization accuracy for the network's regulatory requirements without the excessive power consumption of frequent synchronization attempts.

The system implements a feedback mechanism where nodes receive time synchronization signals from the master node during wake periods and adjust their local time representations accordingly. The synchronization is triggered by wake-up events rather than continuous operation, and the feedback loop ensures that time drift is corrected periodically when nodes are active, achieving acceptable synchronization accuracy with minimal power consumption.