Link quality estimation in VANETs for multi-hop alert messages dissemination

Reception of alert messages by endangered vehicles at time of an emergency event (e.g., a traffic accident) is a prime objective of alert messaging protocols in vehicular ad hoc networks (VANETs). This work proposes a new bi-directional stable communication (BDSC) protocol for relay nodes selection in multi-hop alert messages propagation in VANETs. The BDSC protocol is based on a dynamic link quality estimation algorithm. The proposed protocol is evaluated by assessing the alert messages reachability in varying network size and traffic densities. Results obtained from extensive simulation experiments favour the performance of the proposed protocol with a large margin of reachability improvement compared to conventional furthest distance relay selection protocols. In a multi-lane road segment with dense traffic scenario, reachability improvement of approximately 25% is noticed over the furthest distance protocols. This reachability improvement is achieved with comparable end-To-end communication delays to those exhibited by furthest distance-based solutions.