Efficient dynamic caching for geocast routing in VANETs

Virtual warning system which is an integral component of Intelligent Transportation System (ITS) can be realized through geocasting in vehicular ad-hoc networks (VANETs). It enhances road safety and security by targeting a group of vehicles within a specified geospatial region, called Zone of Interest (ZOI) rather than an individual vehicle. Velocity of the node and dynamic topology are major concerns in vehicular traffic environment which differentiates VANETs from mobile ad-hoc networks (MANETs). This paper purposes neighbor selection scheme based on overlapping area threshold and efficient caching based on threshold time beaconing system to incorporate caching for geospatial packet dissemination which enhances data packet delivery ratio significantly. Due to this the messages that could not be forwarded because of local maximum problem in greedy forwarding are stored in cache which enhances geocast message delivery success ratio. Simulation results show that the purposed approach not only enhances the caching methodology but also minimizes packet loss as compared to greedy forwarding and greedy perimeter stateless routing (GPSR).