PB-MII: replacing static RSUs with public buses-based mobile intermediary infrastructure in urban VANET-based clouds

The success of vehicular ad hoc network (VANET) among vehicle consumers is subject to the quality of comfort and realism of safety promised by this technology. Recently VANET evolved to a rather more application and services-rich paradigm referred to as VANET-based clouds. However, the initial deployment stage of VANET and its successor VANET-based cloud is going to be a daunting challenge due to less market penetration rate of the technology-enabled vehicles, and the deployment and cost of road-side infrastructure. To fill the gaps, in this paper, after arguing on the predictability of spatiotemporal characteristics of the public transport buses in urban areas, we propose a mechanism where these buses are used as mobile gateways (MGs) among vehicles on the road, VANET authorities, and the cloud infrastructure. MGs work as functional entities of the mobile intermediary infrastructure (MII) in VANET-based clouds. Our proposed scheme can serve as a feasible, cost-effective, and pre-established MII for standalone VANET and VANET-based clouds. We furthermore, carry out feasibility analysis through a communication scheme in VANET-based clouds. More precisely we consider the traffic information aggregation and dissemination in VANET-based clouds. In order to argue on the feasibility of buses as MGs, we consider real-time road network dynamics in Seoul, South Korea where the public buses provide perfect connectivity to other vehicular nodes in the neighborhood. In VANET-based clouds application, vehicles share coarse-grained information with clouds through MGs and receive fine-grained traffic information from cloud infrastructure through MGs in real-time. Our simulation results show that MGs provide almost 100% coverage in average traffic scenarios and about 98% coverage in worst traffic scenarios. These MGs also provide the vehicles with about 84% traffic information in worst case and over 90% traffic information in average traffic scenarios. Our proposed infrastructure can be a strong rationale for the initial deployment of these technologies and can possibly be a reasonable partial or full replacement for static RSUs in the urban scenarios.