Flying Ad Hoc Network (FANET) is a novel mobile ad hoc network type where the communicating nodes are Unmanned Aerial Vehicles (UAVs). Deployment of traditional omnidirectional antennas on FANETs lacks to address enhanced spatial reuse demands because interference by simultaneous transmissions limits the maximum number of concurrent communications. Alternatively, utilization of directional antennas can significantly increase the spatial reuse and network capacity of FANETs.
In this paper, we present an analytical study to specify the maximum number of active UAV node pairs for three dimensional (3D) flight scenarios. Specifically, we propose an analysis for various flight scenarios over different types of flights and present the effects of the distance between communicating nodes and the main beam angles on the number of maximum active node pairs.