Validation of high-speed broadband satellite communications on airborne platforms

The desire for satellite-based airborne communications on the move (COTM) has been an emerging trend in recent communication systems. This has been true for both DoD and Civilian systems being deployed. Early implementations of COTM have mostly been focused on the Land-Mobile environment, but this is starting to broaden into other domains as well. There is burgeoning domestic and international interest in airborne platforms to provide high-speed broadband communications. The predominant satellite-based implementations to date have been at frequencies such as L-band, which offers some benefits with omni-directional antennas and large coverage areas. However, these frequency ranges suffer from relatively low data rates (e.g., in the kbps range), overcrowding in key areas of operation, and expensive costs for end users. This has created a desire to shift some of the airborne communications to available Ku and Ka bands, both commercial and military. This paper will clarify the challenges of the airborne environment for satellite communications and present solutions for each of them. Areas that are especially challenging include satellite handover, Doppler correction, and coverage areas. Also, the results of a recent airborne demonstration with very small aperture terminals (VSAT)s are presented to validate a solution to this difficult but indispensable capability.