Synchronous collection protocol of seismic wave based on wireless sensor networks

For the problem that oscillator frequency offset of collecting nodes of wireless sensor networks would cause sampling time error during seismic wave collection of advanced probing system of coal mine seismic wave, quantization relation between oscillator frequency offset of collecting nodes and the maximum sampling times was analyzed by modeling, and a continuous synchronization protocol of wireless sensor networks node was proposed. In the protocol, sink node sends broadcast twice to collecting nodes, and collecting nodes achieve time synchronization with high precision by counting interval of the broadcast. The experimental result shows that the protocol guarantees the maximum sampling time error between the nodes is less than 2 μs during seismic wave collection with sampling frequency of 5 kHz for 3 s.