August 3, 2012:
UAVs are, in some respects, too much of a good thing. The larger ones, like Predator, Reaper, and Global Hawk send most of their video back via satellite. Last year over six million hours of this video went via satellite, and this was about twice what the American military communications satellites could handle.
The United States has been scrambling to find solutions. Building more military communications didn’t work. It took too long (what with all the bureaucracy and politics) and there was always the risk that the procurement system would select a really bad satellite. That sort of thing has been happening a lot lately.
Some solutions have worked. This includes leasing commercial satellites, using "satellite substitutes". These are aircraft, UAVs, or even high altitude balloons carrying a satellite like transponder to send the data to a ground station with access to the international fiber-optic cable system (which the Internet depends on to remain operational). Another solution has been to increase the amount of data sent via the satellite link. This approach uses compression as well as sending multiple streams (multiplexing) of data at once. This is a technique that first showed up in the 19th century, as a means of overcoming too many telegraph messages trying to use a limited number of lines (especially the costly undersea cables). Another technique that is growing in popularity is to use software on the camera end to determine what should be sent and what should be stored on the aircraft for a while. This approach also can use single frames being sent that indicate something might be useful and letting a human at the other end decide if the entire stream should be resumed.