Unmanned aerial vehicle (UAV) communications relay

The Army Communications Electronics Command (CECOM) Space and Terrestrial Communications Directorate (S&TCD) is conducting a multi-year airborne communications range extension program, primarily in support of the Battlefield Information Transmission System (BITS) initiative. The main objective of this program is to provide beyond line of sight communications (BLOS) capabilities within an area of operations under direct control of the theater commander without using scarce satellite resources. The S&TCD effort includes the planning and implementation of a series of demonstrations and advanced warfighting experiments compatible with overall BITS schedules and goals. It is planned to use UAVs as platforms for a high capacity trunk radio relay, and a UAV based battlefield broadcast system. Future applications are expected to include an airborne personal communications system. The range of coverage provided by practical airborne platforms, a function of altitude and the elevation or look angle of the transmitters or receivers, can vary from 50 to 100 miles for UAVs of interest. The platform payload for all applications will be bent-pipe, non-processing, block conversion type transponders with provisions for cross-banding. All antennas are to be wide beam, at least 165° in elevation and 360° in azimuth with the potential for implementing shaped beam or tracking antennas. To be effectively applied, airborne relays using UAVs must maintain compatibility with the existing and planned terrestrial and space communications infrastructures