RBO-EM: Reduced Broadcast Overhead Scheme for Emergency Message Dissemination in VANETs

Abstract

Effective information dissemination constitutes the cornerstone of communication in Vehicular Ad hoc Networks (VANETs). Avoiding broadcast storm is one of the considerable challenges in the development of an effective dissemination scheme for VANETs, which leads to extensive rebroadcasting. Reliable emergency messages delivery is another substantial measure of performance, especially in dense traffic and high mobility scenarios. A generic solution to deal with these problems is to cluster vehicles, so that emergency messages can be re-broadcasted to adjacent clusters only by a smaller number of vehicles. Thus, reliable selections of cluster head and relay nodes are important to reduce the number of retransmissions. In this regard, we propose a clustering technique for Reduced Broadcast Overhead Scheme for Emergency Message Dissemination (RBO-EM). RBO-EM is based on the mobility metrics to strengthen the cluster formation, avoid communication overhead and maintain the message reliability in a high mobility scenario. Moreover, we introduce relay nodes based on estimated link stability to limit the number of retransmissions. RBO-EM is evaluated against eminent schemes by varying traffic densities and speed. Simulation results indicate that RBO-EM enables a reasonable performance gain in terms of coverage, end-to-end delay and message reliability.

EEMDS: An Effective Emergency Message Dissemination Scheme for Urban VANETs

“…Every node periodically broadcasts beacon messages to the neighbor nodes to exchange information, such as N_id, velocity, position, and node state. The receiving node updates its β based on (2) and (4), which can be used in a cluster formation phase.…”

“…Similarly, in [ 2 ], the network is hierarchically partitioned into several clusters on a highway, where all the cluster members are connected to a . In order to restrain redundant transmission for reliable EM dissemination, only is responsible for retransmitting EMs in each cluster.…”

“…In order to restrain redundant transmission for reliable EM dissemination, only is responsible for retransmitting EMs in each cluster. In addition, [ 2 ] uses a relay node to maximize coverage and has been shown to work well in highway environments. In this paper, we propose EEMDS as an extension of [ 2 ] to urban environments.…”

“…In addition, [ 2 ] uses a relay node to maximize coverage and has been shown to work well in highway environments. In this paper, we propose EEMDS as an extension of [ 2 ] to urban environments. Unlike [ 2 ], EEMDS employs path loss factor using two-ray ground propagation model to consider line-of-sight as well as the reflected signals for and relay node selection.…”

“…Vehicles encountering a hazard disseminate EMs to other vehicles (hereinafter nodes) within their communication vicinity. This enables nodes to take adequate preventive measures, such as re-routing, to avoid road accidents, travel delays, and traffic congestion [ 2 , 3 ]. In VANETs, the most common and easiest way of disseminating EMs is flooding [ 4 ], in which a source node broadcasts EMs to other nodes within its transmission Range ( R ).…”