Abstract: The rapid development of wireless communication technology makes it possible to transmit the data for vehicle control between the vehicle and ground by radio . The key points are the reliability and availability of wireless transmission, especially under high speed. The characteristics of wireless channel in ITS and IRTS are analyzed. Then the reliability and availability of wireless transmissio n for high-speed vehicle control are analyzed. A channel model is set up to dete ct the effect of vehicle speed on error rate. Measures are taken to improve the wireless link performance based on the channel property. Finally, methods are pr ovided to decide if the error rate meets the requirement of high speed vehicle c ontrol on ITS or IRTS.