Content Caching Algorithms in Drone-Aided Ad Hoc Networks

Content delivery networks (CDNs) lead to fast content distribution through content caching at specific CDN servers near end users. However, existing CDNs based on infrastructure cannot be employed in special cases, such as military operations. Thus, a temporary CDN without an existing infrastructure is required. To achieve this goal, we introduce a new CDN for drone-aided ad hoc networks, whereby multiple drones form ad hoc networks and quickly store specific content according to new caching algorithms. Unlike the typical CDN server, the content-caching algorithm in the proposed architecture considers the limited storage capacity of the drone. We present three content distribution algorithms that consider the constraints and mobility of drones. The main contribution of content caching for drone-aided ad hoc networks is to keep partial segments rather than whole content as well as move the drone near to area with a high volume of requests. The proposed scheme is evaluated to demonstrate its feasibility in terms of content acquisition time and utilization in several practical scenarios through simulations. Consequently, acquisition time in CDN to support drone movement is improved by approximately 50 $\mathrm{\%}$ and $40\mathrm{\%}$ rather than one in the proposed naive greedy approach as a function of content request interval and size, respectively.