Vehicular Networks QoS Improvement by Simultaneous Use of RSUs and Parked Vehicles in Urban Scenarios

By growth in urban population, vehicles have also experienced increased significantly. The increased of vehicles has led to challenges in the services of safety, traffic and comfort. Congestion in urban areas is one of the main examples of increasing the number of vehicles, which has also led to environmental challenges. To address these challenges, Intelligent Transportation Systems (ITS) have been developed. One of the key technologies in ITS to solve these challenges is vehicular networks. These networks increase the efficiency of transportation systems in urban and highway areas by providing a wide range of services. However, these networks face challenges such as network partitioning in low-density areas and lack of network capacity in dense areas to providing proper services. Such challenges will reduce the efficiency of vehicular networks and transportation systems in urban and highway scenarios. To overcome these problems, roadside units are deployed in urban environments, but the high cost of installation and maintenance of RSUs prevents their widespread installation in urban areas. Therefore, it is necessary to install a minimum number of these units in the urban environment and in suitable and necessary places to meet these challenges. The presence of parked vehicles in urban areas and in predetermined places, makes it possible to use them as RSUs. Therefore, it is necessary to consider the location of parking lots in the placement of roadside units in the urban environment so that parked vehicles in these places can be used as roadside units to meet these challenges. Therefore, it is necessary to consider the location of parking lots in urban areas in the placement of RSUs. In this paper, a BIP model for RSUs installation is developed to provide the minimum required coverage by considering parked vehicles as RSUs in the urban area to meet the mentioned challenges. In this model, parked vehicles in parking lots are used as RSUs to increase coverage and capacity of the network. Moreover, constraints have been added to the model to achieve the minimum required coverage and minimize multiple co-coverage to reduce installation costs. Therefore, in the proposed model, in addition to considering the parked vehicles in the parking lots as roadside units and restrictions to prevent multiple coverages in order to reduce installation costs, providing minimum coverage to improve the efficiency of ITS services is also considered. Finally, the proposed solution is evaluated using OMNeT++, SUMO and Veins. To validate the proposed model, the evaluation was repeated in two different maps, with a different number of RSUs and different traffic scenarios, and Packet Loss Rate and Service Delay were measured as performance parameters. The results of the simulation show the improvement of the service delay parameter in the two maps by 39% and 43% and the packet loss rate by 47% and 49% compared to other related work.