Geo-routing in urban Vehicular Ad-hoc Networks: A literature review

Intelligent Transport Systems (ITS) and the open-ended research in the field of vehicular communication attempts to deal with the road traffic problems. In Vehicular Ad-Hoc Networks (VANETs), vehicles are moving faster in comparison with Mobile Ad-hoc Networks (MANETs). Furthermore, in urban VANETs, vehicles are constrained by the layout of the roads and buildings, which causes shadowing effects. On the other hand, ITS promises traffic management, road safety and comfort applications, that have their Quality-of-Service (QoS) requirements. Thus, one of the key factors to the successful establishment of VANETs is a routing protocol to meet these QoS requirements. Geo-routing protocols are appropriate for VANETs, as a result of their simplicity, efficiency and scalability. Because of the large number of the proposed geo-routing protocols, it is requisit to have a comprehensive collection of the materials on this topic to provide a solid background for a research paper's investigation. This paper presents an overview of the state of the art geo-routing protocols for urban VANETs.