Table of Contents
International Journal of Vehicular Technology
Volume 2012, Article ID 905396, 14 pages
Research Article

Context-Aware Multicast Protocol for Emergency Message Dissemination in Vehicular Networks

School of Electrical Engineering and Computer Science, Queensland University of Technology, GPO Box 2434, 2 George Street, Brisbane, QLD 4000, Australia

Received 17 January 2012; Revised 21 March 2012; Accepted 19 June 2012

Academic Editor: T. A. Gulliver

Copyright © 2012 Alvin Sebastian et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Road traffic accidents can be reduced by providing early warning to drivers through wireless ad hoc networks. When a vehicle detects an event that may lead to an imminent accident, the vehicle disseminates emergency messages to alert other vehicles that may be endangered by the accident. In many existing broadcast-based dissemination schemes, emergency messages may be sent to a large number of vehicles in the area and can be propagated to only one direction. This paper presents a more efficient context-aware multicast protocol that disseminates messages only to endangered vehicles that may be affected by the emergency event. The endangered vehicles can be identified by calculating the interaction among vehicles based on their motion properties. To ensure fast delivery, the dissemination follows a routing path obtained by computing a minimum delay tree. The multicast protocol uses a generalized approach that can support any arbitrary road topology. The performance of the multicast protocol is compared with existing broadcast protocols by simulating chain collision accidents on a typical highway. Simulation results show that the multicast protocol outperforms the other protocols in terms of reliability, efficiency, and latency.