Map Aware Dual-Mode Geocast Routing in VANETs

Abstract

Geocast is a communication technique to disseminate information in specific geographic regions instead of node addresses. Geocast routing in VANETs have become an area of interest for researchers. Traffic congestion, accidents and local hazards are examples of use cases of information sharing in VANETs. As geocast is an important part of ITS (intelligent transport system), many geocast routing protocols have been proposed in the past. Yet, geocast region selection techniques for VANET routing have not been studied in detail so far. In this paper we propose a map aware geocast routing protocol for information dissemination in VANETs. The target regions are selected by constructing a probability tree and information is disseminated along the branches of tree. Vehicles use two different packet forwarding modes based on their direction towards the hazardous road. Packets are forwarded towards the target regions by selecting the fastest neighbor vehicles. Moreover, packets broadcasted from the vehicles at intersections are given priority to disseminate information on all roads across the intersection. We evaluate our approach through extensive and realistic simulations and results show that our geocast routing protocol shows better delivery ratio and improved end to end delay as compared to existing method.