An enhanced directional greedy forwarding for VANETs using link quality estimation

Abstract

Vehicular Ad hoc Network (VANET) is emerging as a new technology to support safety, entertainment, and traffic efficiency applications in smart transportation systems. Since VANET is a subclass of Mobile Ad hoc Network (MANET), performance of MANET routing protocols when applied to VANET have been studied extensively during the last years. One of the most interesting areas is applying geographic routing to VANETs since it does not require route establishment nor does it require route maintenance. Most of the work in this area is focused on selecting the closest next-hop to destination without considering link quality. Geographic routing tend to select nodes at the border of the communication range. As the distance between a sender and a receiver increases, the link becomes less stable due to local environment conditions such as interference and node's mobility. Thus, geographic routing may lead to poor selection of next-hop which affects the routing reliability and degrades the performance of real-time safety applications in VANETs. In this paper, we propose an enhanced directional greedy forwarding (DGF-ETX) that incorporates the well known link quality estimation metric, ETX, into a multi-metric routing function that considers distance and direction of candidate forwarders. Results from our simulation experiments of dense urban environments show that using ETX with distance and direction reduces the packet loss ratio while Packet Delivery Ratio (PDR) and the total network throughput is increased.