Construction of Ad-Hoc Public Safety Communications Networks Using EVs as Base Stations in Disaster Scenarios

Recently, mobile traffic has increased and is expected to increase further. Therefore, the deployment of high-density networks with many small-cell base stations within the coverage area of the macro-cell base station is being considered as a network that can increase the capacity of mobile networks. The open-radio access Network (O-RAN), which divides the functions of the radio access network, has also attracted attention. However, in the networks, the function of the base station stops presumably because of power outages or failures in the event of disasters, resulting in the failure of user equipments (UEs) to communicate with external networks. Then, use of Electric Vehicles (EVs) with base station functionality as alternatives to base stations during disasters is being considered. Therefore, this study examines networks using the aforementioned EVs and highlights the problems caused by inoperable EVs on UEs that cannot communicate with external networks and the need for power consumption by network operation and movement during disasters. Furthermore, we propose a method to rebuild networks by considering the power consumed by network operation and movement. In the proposed method, we model the system, express each power consumption mathematically, and optimize the placement of EVs and transmission power. In addition, the results of the experiments validate the effectiveness of the proposed method in various environments. The reduction in the power consumed by the network operation and movement improved the feasibility of these networks.