Appropriate Roadside UnitsPlacement in VANET Networks to Reduce Data Transfer Time

VANETs, as a subset of the MANETs, have progressed remarkably in recent years. These networks have an important role in improving traffic, road safety and driver service. In vehicle Networks, vehicle can Communication by vehicle-to-vehicle communication. Since there are fewer vehicles in the environment, there is no vehicle-to-vehicle connection in some areas. Therefore, they use Road Side Units (RSUs) alongside vehicles to send and receive information. Roadside equipment, in addition to information dissemination, has a significant impact on communication, routing and transmission with minimal delay. The efficiency of a VANETs dramatically depends on the density, position and coverage of these units. Because of the high cost of installing and maintaining roadside units, there is no way to cover the entire environment, so we need to install them in places that will save costs and reduce the time needed to transfer information, in addition to reducing costs. The purpose of this paper is to target the minimum number of roadside units in the urban area, so that messages can be transmitted to the roadside units within the range of delayed emissions. In this research, a delay analysis is presented in urban environments, and based on this analysis, the RSU Optimization Placement problem is solved with greedy algorithm and imperialist competitive algorithm. Simulation results show that this roadside installation pattern has improved network performance and reduced cost