Unmanned Aerial Vehicle Relaying System in Forest Disaster Areas
Abstract
As the frequency and intensity of forest disasters increase due to climate change, reliable communication infrastructure for effective disaster response becomes increasingly critical. Forest areas present challenging conditions with numerous communication shadow zones due to their topographical characteristics, and existing communication infrastructure may be damaged during disasters, hindering rapid response. In this paper, we present the design, prototype implementation, and field evaluation of a drone-mounted LTE relay system for emergency communication in forest disaster areas. The relay platform integrates an interference cancellation subsystem (ICS) within a drone-deployable form factor (approximately 4.5 kg and 54 W class) and is operated in two configurations: a tethered (wired) configuration for extended-duration operation and a battery-powered (wireless) configuration for rapid deployment into shadow zones. The only physical difference between the two configurations is the power supply method; the RF relay chain is identical. The system is evaluated through laboratory measurements and field tests at a forested test site with seven measurement points spanning both line-of-sight and shadow regions. At measurement points where both direct and relay links are available, the field measurements show downlink throughput improvement of up to 233% at Pt4 and uplink throughput improvement of up to 202% at Pt2. In shadow-zone points, the wireless drone relay restores usable LTE service where direct base station reception is unavailable.