The wireless Internet of Things system is essentially a software defined radio technology implementation. Considering the requirements for long-distance/anti-interference communication capabilities, the physical layer adopts OFDM adaptive adjustment method and optimizes channel estimation, which can effectively compensate for Doppler frequency offset, support vehicle movement at 80 kilometers per hour, and achieve cross base station switching or dynamic self-organizing network in self-organizing network mode. The MAC layer adopts 802.11 connectionless mode and corresponding frame format, optimized and enhanced for mobility. To avoid bandwidth loss caused by multi node CSMA/CD conflict detection, the system implements uplink time-division multiplexing, which can effectively support applications with multiple video uploads.