An Efficient and Reliable QoF Routing for Urban VANETs with Backbone Nodes

Abstract

Because of the dynamic topology, high mobility of nodes, and complicated channel environments in urban areas, existing routings methods are susceptible to frequent link interruptions and channel congestions. To address these issues, a Quality of Forwarding (QoF)-based reliable geographic routing (QFRG) in urban vehicular ad hoc networks (VANETs) is proposed, where the best route is determined by guaranteeing the QoF and satisfying the link reliability requirement. Two theoretical models for QoF and link reliability analysis are first presented. Taking into consideration the transmission cost and the packet delivery ratio, the QoF is, then, employed to provide the quantitative evaluation to the road segments through the presented road weight evaluation (RWE) scheme, which takes into account the impact of the relative position of links on the network performance. Next, to accommodate the network scale of an urban city, the city map is divided into smaller grid zones. Based on the position of the destination, different transmission strategies are presented for packet forwarding. The extensive simulations demonstrate our protocol's superiority in both transmission delay and packet delivery ratio compared with the existing schemes.