Geolocation-based sector selection for Vehicle-to-Infrastructure 802.11ad communication

Abstract

To improve range, IEEE 802.11ad uses directional communication, the first step of which is to choose the best antenna configuration, known as 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. First, we created a framework for mm-Wave data collection in mobile scenarios, highlighting the challenges, justifying our solutions, and making them available, thus flattening the path for future experimentation by others. We then proceeded to use said framework to collect data in a realistic V2I communication scenario. We performed two independent measurement campaigns in the same area. Analysis of the collected data revealed the following inefficiencies in the devices’ sector selection algorithm: (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 propose 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 a position-based strategy can improve throughput by more than 10% for 30% of locations, and that gains can be as high as 60%, in some instances.