A multi-channel VANET providing concurrent safety and commercial services

Abstract

In this paper, we propose a medium access control (MAC) protocol to support the multi-channel operation for dedi-cated short range communication (DSRC). In particular, we focus on the challenge of providing potentially high-bandwidth for non-safety applications provided by road-side infrastructure, without compromising safety commu-nication occurring in a separate channel. In our architec-ture, when a vehicle approaches a DSRC service hot-spot, it switches from the ad-hoc mode to the coordinated mode (and switches back to ad-hoc as it leaves the hotspot’s range). This coordinated mode is a variant of IEEE 802.11 PCF, modified for multi-channel operation. The coordinated mode maximizes utilization of the DSRC “service channels ” in the DSRC hot-spots while allowing safety-message broadcasts to be received with high probability in a distinct “safety chan-nel”. When a vehicle is not within the range of a DSRC hot-spot, the vehicle can use any of the previously-proposed ad-hoc protocols. Our approach can use any of these ad-hoc protocols for its ad-hoc mode. The MAC protocol is simu-lated with realistic mobility trace, and verified that it meets our safety and service objectives.