Evaluation of the Universal Geocast Scheme for VANETs

Recently, a number of communications schemes have been proposed for Vehicular Ad hoc Networks (VANETs). A promising approach, the Universal Geocast Scheme (UGS), provides for a diverse variety of VANET-specific characteristics such as time-varying topology, protocol variation based on road congestion, and support for non line-of-sight communication. In this paper, the UGS protocol is extended to consider inter-vehicle multi-hop connections in intersections with surrounding obstructions. Since UGS is a probabilistic, repetition-based scheme, it supports the capacity-delay tradeoffs crucial for periodic safety message exchange. The approach is shown to support both vehicle-to-vehicle and vehicle-to-infrastructure communication. This research accurately evaluates this scheme using network (NS-2) and mobility (SUMO) simulators, verifying two crucial elements of successful VANETs, received packet ratio and message delay. A contemporary wireless radio propagation model is used to augment accuracy. Our results show a 6% improvement in received packet ratio combined with a decrease in average packet delay versus a previous, well-known inter vehicle communication protocol.