A Practical Approach to Deploying a Drone-Based Message Ferry in a Disaster Situation

Unmanned aerial vehicles (UAVs) are commonly used in disaster recovery efforts to confirm the extent of the damage caused by a large-scale disaster and to ensure that adequate information about the affected area is gathered. UAV usage in a disaster situation is not limited to information gathering, but its functions further extend to network communication functions such as a communication relay, mobile base station, etc. Conversely, using UAVs as communication relays or base stations (e.g., as a temporary mobile base station) is subject to some limitations such as bad weather and limited energy, which affect the timely collection and delivery of information to and from a disaster area. Therefore, an approach to improve the information collection and delivery in a disaster area while ensuring urgent network restoration is necessary. In this paper, we introduce a practical approach to deploying a drone-based message ferry to improve the timely collection and delivery of information in a disaster situation. Specifically, a locally accessible cloud system (LACS), which we previously developed for urgent local network restoration in a disaster affected area, is attached to a drone to form a message ferry. In order to improve the information collection and delivery, the message ferry is deployed from the local headquarters (i.e., local government office or disaster response coordination center) to carry information to and from a standalone LACS installed at each disaster shelter. We measure the achievable data rate of inter-LACS data transfer (i.e., message ferry and a standalone LACS) through experiment. Thereafter, we estimate and confirm the effective transmission speed to transfer data from the local headquarters to the disaster shelters using average achievable data rate obtained from the experiment in order to extend the LACS services and functions. Our experimental results and analysis suggest that the proposed message ferry is more advantageous to transfer a large amount of data (e.g., 300 MB) at a high speed in the hundred meter to ten kilometer range.