GROOV: A geographic routing over VANETs and its performance evaluation

Owing to the features of erratic speeds and varying topography and requirements of minimum delay and high application reliability in terms of data delivery and security, existing MANET routing protocols prove to be inefficient in VANETs. In acknowledgment to the requirement for new VANET protocols addressing issues of routing, data dissemination, data sharing and security, this paper proposes a novel geographic routing technique called GROOV, which takes into account varying topographies and densities of highways as well as cities. To increase reliability, GROOV calculates transmission feasibility for each node, based on link quality (average acceleration), range weight (weightage to relative positions of nodes) and direction, instead of traditional greedy forwarding, in the selection of the next relay node. Taking volatility of critical city intersection scenarios into account, GROOV calculates new node coordinates of vehicles at intersections to make best route selections at intersections and thus, routes the data packet through the path directed at the intended recipient. This prevents the occurrence of a routing loop, thereby, decreasing delay and increasing packet delivery ratio. Simulation results show that GROOV achieves a high level of routing performance in terms of packet delivery ratio, end-to-end delay and average number of hops in both city straight road/highway and city intersection scenarios.