Abiding Regional Data Distribution Using Relay and Random Network Coding on VANETs

Distributing data items such as pictures and videos about traffic conditions at a location a driver wants to go through Vehicular Ad hoc Networks (VANETs) poses a great challenge due to network dynamics and high-speed mobility. In the last decade, random network coding (RNC) has been shown to support content distribution efficiently in such dynamic environments. Our goal is designing a method for continuously providing location-dependent information generated by vehicles to other vehicles being driven near the birthplace of a data item with short delays and low data delivery traffic using VANETs. So far, we have proposed a scheme called R2D2V (RNC-based Regional Data Distribution on VANETs), a rapid and reliable data dissemination method using random network coding in such a situation. R2D2V can achieve a high data delivery ratio for vehicles driving near the birthplace of the information with low data delivery traffic and short delays when the vehicle density is high. However, this scheme cannot achieve a high delivery ratio for vehicles newly coming to the birthplace of the information after the information has been generated. In this paper, we propose new schemes to mitigate the drawback of R2D2V. Our new schemes distribute a data item encoded by RNC to all vehicles driving near the birthplace of the data item by controlling the probability of sending the data in accordance with the elapsed time from data generation, vehicle's moving direction and vehicle's current location. The simulation results show that our proposed schemes can achieve a high delivery ratio for vehicles newly coming near the birthplace of the information with shorter delays and less delivery traffic than R2D2V.