Performance evaluation of IEEE 802.11p physical layer infrastructure-to-vehicle real-world measurements

We evaluate the physical layer of infrastructure-to-vehicle communications from real-world measurements. For the measurements, a prototypical implementation of IEEE 802.11p was deployed in two roadside units (RSUs) along a highway in Austria. The required signal-to-noise ratio (SNR) for achieving a frame-error-ratio (FER) less than 0.1 is estimated from measurements for various configurations of data rate, packet length, and vehicle speed. Evaluations show that for a RSU with an antenna mounted at a low height (1.8m) the required SNR depends on the packet length. This is not the case for a RSU, where the antenna is mounted higher (7.1 m). Further the averaged required SNR over all different parameter settings for the low RSU is 4.6 dB larger compared to the required SNR for the high RSU.