WLAN/WDS Performance Using Directive Antennas in Highly Mobile Scenarios: Experimental Results

This paper presents experimental results from a series of IEEE 802.11g studies to investigate the performance of vehicular to roadside wireless communications. In particular, two high-gain omni-directional antennas were used at the roadside access point, while high-gain omni-directional and directional antennas were compared for use on the vehicle. By employing high-gain antennas at both ends of the wireless link, the range of the WLAN network was dramatically improved. Moreover, the use of directional antennas in highly mobile applications allows communication at higher vehicle speeds (by reducing the Doppler spread) and longer ranges (by reducing delay spread and increasing the received power level).