A framework for reliable exchange of periodic and event-driven messages in platoons

Platooning is widely considered a promising approach to decrease fuel consumption by reducing the air drag. However, in order to achieve the benefits of aerodynamic efficiency, the inter-vehicle distances must be kept short. This implies that the intra-platoon communication must not only be reliable but also able to meet strict timing deadlines. In this paper, we propose a framework that reliably handles the co-existence of both time-triggered and event-driven control messages in platooning applications and we derive an efficient message dissemination technique. We propose a semi-centralized time division multiple access (TDMA) approach, which e.g., can be placed on top of the current standard IEEE 802.11p and we evaluate the resulting error probability and delay, when using it to broadcast periodic beacons and disseminating event-driven messages within a platoon. Simulation results indicate that the proposed dissemination policy significantly enhances the reliability for a given number of available time-slots, or alternatively, reduces the delay, in terms of time-slots, required to achieve a certain target error probability, without degrading the performance of co-existing time-triggered messages.