Long-Range and Broadband Aerial Communication Using Directional Antennas (ACDA): Design and Implementation

In this paper, we design and implement a long-range and broadband aerial communication system using directional antennas (ACDA). The system integrates Wi-Fi devices with aerial networks to quickly establish a Wi-Fi infrastructure in the air, which provides real-time communication capability for disasters where a fixed communication infrastructure does not exist. ACDA utilizes unmanned aerial vehicle (UAV)-carried directional antennas to extend communication range, increase throughput, and reduce interference. A GPS-based control algorithm is designed and implemented to automatically reject wind disturbance and align the directions of antennas in accordance with UAV movement. A received signal strength indicator-based decentralized initial scan algorithm is also designed and implemented to quickly establish initial connection between the UAVs. Simulation studies verify the effectiveness of the heading control and initial scan algorithm. Field tests are also conducted to evaluate the performance of overall system in terms of throughput and delay with respect to the increase of communication range. The ACDA prototype system achieves 48 Mb/s throughput at a distance of 300 m and 2 Mb/s at 5000 m, and proves the promising usage of directional antennas for long-distanceWi-Fi aerial communication. Practical use of this on-demand communication system to aid emergency response is also demonstrated through a case study in a real disaster drill.