Opportunistic service promotion for end-to-end delay minimization in IEEE 802.11p vehicular networks

IEEE 802.11p Wireless Access for Vehicular Environments (WAVE) is the envisioned communication protocol for Vehicular Ad-hoc Networks (VANETs) and Intelligent Transportation Systems (ITS) applications. WAVE offers service differentiation by prioritizing packets based on an application´s QoS requirements. This is accomplished by a multi-channel approach where a channel consists of multiple priority queues. Currently, WAVE uses static packet priorities without accounting for network load. In this paper, we propose a novel opportunistic service promotion technique for IEEE 802.11p (WAVE) to dynamically route lower priority packets through higher priority queues while meeting the required QoS w.r.t delay for all queues and underlying network link layer bounds. This will increase the QoS w.r.t end-to-end delay of all ITS applications. To show correctness and feasibility, our methodology entails formulating the opportunistic service promotion technique as an Integer Linear Programming (ILP) problem. We solve it to guarantee minimum overall end-to-end delay. We show significant improvement averaging at 30% decrease in the end-to-end delay over classical WAVE implementations.