# A Practical Approach to Deploying a Drone-Based Message Ferry in a Disaster Situation +
###### Abstract
Furthermore, extensive applications of UAV as a communication relay in delay tolerant and ad-hoc networks have been studied. For example, Refs. [5,6] proposed the use of mobile base station and UAV as an aerial base station to ensure that people in a disaster area can communicate with their families within and outside the affected area. However, utilizing UAV as a temporary base station in the aftermath of a large-scale disaster has some limitations [7]. One such limitation is the excessive calls from people trying to communicate with their relatives. These excessive calls lead to network congestion due to the increase in network traffic. It has been confirmed in the past that the network traffic during a large-scale disaster increased 60 times with respect to the average network traffic [8,9]. Additionally, the operation of the UAV as a base station is subject to other limitations like poor weather conditions, complex deployment logistics, and limited power supply [10]. In spite of numerous studies conducted on the use of UAV in disaster recovery efforts and various solutions proposed to resolve the challenges of accessing vital information after a large-scale disaster has occurred [11,12], accessing accurate and urgent information in real-time in a disaster area is still a major challenge. Furthermore, the decision-making for a timely disaster response is also affected as a result of the real-time information synchronization issue [13] that may be caused by MANET's constraint [14], e.g., intermittent connection failure, network congestion, limited network or device resources, security and information integrity. Hence, a method that can be used to collect and provide critical information in a timely manner is needed to enhance disaster response and management. Previously, we proposed an improved approach for realizing the timely and efficient collection and delivery of disaster information based on the Locally Accessible Cloud System (LACS) (described briefly in Section 2.3) [15] to urgently restore and /or deploy ICT environment locally in the disaster area [16,17]. Specifically, LACS is installed in the evacuation shelters to reestablish the network communication and provide a means for people to communicate locally after a disaster has occurred and the communication infrastructure is destroyed. Thereafter, a vehicle mounted with LACS (referred to as movable LACS hereafter) deploy from the local headquarters (i.e., local government office or disaster response coordination center) tours each shelter to collect/deliver vital information from/to the evacuees. In addition, when the LACS installed in the shelter and the movable LACS establish a network connection, data can be synchronized automatically between the two LACSs using the synchronization function implemented on LACS. The synchronized information on the local LACS can be accessed by the evacuees. However, the service area covered by a LACS is limited to about hundred meters in radius due to the Wi-Fi characteristics and it may hamper the efforts to collect and deliver accurate information. To increase the coverage distance of the movable LACS in a timely manner, it is necessary to consider an alternative approach that can be used to improve the information collection and delivery in a disaster affected area. This paper proposes a practical approach to deploying a drone-based message ferry that can be utilized in collecting and delivering disaster information after a disaster has occurred. To create a message ferry in our proposal, LACS is attached to a drone (i.e., the physical LACS device is attached to the drone). LACS has a storage and communication functions which are combined with the drone function to form the message ferry. The communication of the message ferry is based on LACS Wi-Fi.