Co-existing periodic beaconing and hazard warnings in IEEE 802.11p-based platooning applications

Abstract

A platoon of trucks driving at the same, mutually agreed speed while keeping a minimum inter-vehicle distance will reduce fuel consumption, enhance transport efficiency as well as improve the safety of other adjacent road users. The European profile of IEEE 802.11p for inter-vehicle communications uses a single 10 MHz control channel dedicated to safety-critical data, shared by periodic status updates, CAM (Cooperative Awareness Message), and event-triggered warnings, DENM (Decentralized Environmental Notification Message). Coupled with the random access delay inherent to the 802.11p medium access method, the strict timing and reliability requirements of platoon applications are not easily met. To this end, we evaluate by simulation the effect of IEEE 802.11p-compliant send rate adaptations and message type prioritizations and the choice of warning dissemination strategy on CAM transmissions and DENM dissemination in a platooning scenario. Simulation studies of a platoon of 10-20 vehicles in a busy highway scenario show that the context-aware choice of send rate, priority class and dissemination strategy not only reduce the dissemination delay of DENMs but even has a significant effect on the throughput of CAMs exchanged by platoon members.

Infrastructure-Assisted Message Dissemination for Supporting Heterogeneous Driving Patterns

“…Simulation shown that VeSOMAC can offer better vehicle safety through smaller and bounded packet latency. In [16], the authors evaluated the coexistence of periodic and event-driven data traffic in a safety-critical platooning application. An event-based safety message dissemination strategy was proposed to support vehicle platooning application.…”

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

“…If event-driven messages should co-exist with beacons, the update rate should be as low as possible while still providing enough data to control the process. The beacon update rate should then be adjusted based on the current PER [14].…”

“…An overview of information dissemination protocols for VANETs is given in [17]. In [14], the dissemination delay in platooning is considered as a performance measure, i.e., the delay between event detection (e.g., the leading vehicle in the platoon detecting an upcoming traffic jam) and the point in time when the entire platoon successfully received the warning. In order to maintain fuel-efficient inter-vehicle gaps within the platoon while providing the required levels of traffic safety, the need for efficient dissemination strategies of event-driven messages co-existing with high update rate beacons on the same channel emerges.…”

An Efficient Message Dissemination Technique in Platooning Applications

“…Kaul et al [9] identifies the age of periodic beacons in vehicular networks as an important performance metric and propose a rate control algorithm to improve its properties. In [10] several information dissemination protocols for VANETs in general are reviewed and in [11], the dissemination delay in platooning is specifically considered. The dissemination delay is defined as the delay between event detection (e.g., the leading vehicle in the platoon detecting an upcoming traffic jam) and the point in time when the entire platoon successfully received the warning.…”

“…Different ways of mitigating broadcast storms associated with message dissemination within VANETs have been evaluated in [12] and in [13] where several selective broadcast algorithms are compared from an application perspective using simulations. Co-existence strategies for beacons and event-driven messages are considered in [14] for VANETs in general and in [11,15] for platooning applications. In [15], a combined decentralized/centralized channel access approach is adopted, using real-time schedulability analysis to determine the ratio of bandwidth required for beacons and event-driven messages, respectively.…”