Geolocation-based Sector Selection for Vehicle-to-Infrastructure 802.11ad Communication

To improve range, 802.11ad uses directional communication, the first step of which is to choose the best antenna configuration, or sector. We studied the sector selection behavior of Commercial Off-The-Shelf (COTS) 802.11ad equipment in an experimental Vehicle-to-Infrastructure (V2I) communication scenario. Analysis of the collected data revealed the following inefficiencies: (i) a large number of sector selection attempts that do not result in a sector change; and (ii) a “ping-pong” effect in which a node oscillates between two sectors. With this in mind we studied an alternative antenna sector selection scheme that uses spatially-indexed historical performance data to pick the statistically-best sector for any given geolocation. A trace-based analysis showed that such a strategy can potentially improve throughput by up to 60%, depending on location.