SPACE: Never Enough Bandwidth

 In Space, FVEY, P5


will be matched in con­tent – >

October 17, 2020: As the U.S. export more of its large UAVs, like the Predator and now the Reaper, it found itself with a prob­lem. The latest model Predator B (Reaper), the MQ-9B SkyGuardian makes heavy use of its satel­lite link. The prob­lem is these new, larger (5.6 ton versus 4.6 ton) SkyGuardians have a lot more sen­sors and high-res­o­lu­tion vid­cams. To send all this video back to the oper­a­tors, espe­cial­ly the high-res video, requires a lot of band­width (data trans­mis­sion demand), more than the American mil­i­tary satel­lite system can handle. A solu­tion has been to find com­mer­cial com­mu­ni­ca­tions satel­lites that can handle the high-band­width and low-laten­cy (fast response) data trans­fer new sur­veil­lance satel­lites like SkyGuardian require for best per­for­mance. Over the last decade the United States has built a mil­i­tary com­mu­ni­ca­tions net­work opti­mized to serve its UAVs and manned air­craft send­ing video and radar data to the ground or other air­craft or ships. Foreign cus­tomers for SkyGuardian and the mar­itime patrol vari­ant SeaGuardian expect and requite high-band­width and low-laten­cy sat links to per­form as adver­tised. This has led to sales of these UAVs includ­ing the man­u­fac­tur­er find­ing suit­able com­mer­cial com­mu­ni­ca­tions. While the U.S. mil­i­tary does have sur­plus band­width, this is reserved for emer­gen­cies (mil­i­tary or civil­ian). In such cases the U.S. would share some of this band­width with allies. Even so, there will always be a short­age of high-per­for­mance band­width for larger UAVs, espe­cial­ly those doing mar­itime patrol. These UAVs, like SeaGuardian have high-res cam­eras and radars to search coastal areas not matter how over­cast it is at sea level. High-res cam­eras are vital to deter­mine what is going on down there, espe­cial­ly of the mar­itime sur­veil­lance involves look­ing for small smug­gler, pirate or ter­ror­ist boats. It’s not enough to build a UAV with all the needed mar­itime patrol sen­sors, you have to get that data back to oper­a­tors in near real-time.

The U.S. mil­i­tary has, since the 1990s, been a major and increas­ing user of com­mu­ni­ca­tions satel­lites. Not only mil­i­tary owned but also leased band­width from com­mer­cial satel­lites. Back in 2010 the mil­i­tary feared that there might not be enough com­mer­cial band­width avail­able for lease to handle heavy wartime loads. That turned out to be less of a prob­lem than pre­dict­ed because of the rapid­ly grow­ing number of com­mer­cial users for high band­width ser­vices (like stream­ing video). Now the mil­i­tary sees wartime short­ages as less likely because during a nation­al emer­gency com­mer­cial satel­lite owner can be com­pelled to lease band­width to the mil­i­tary and that com­mer­cial band­width is grow­ing so fast that there was more than ten times more of it in 2020 than in 2016.

The U.S. Department of Defense is trying to get more money for its own com­mu­ni­ca­tions satel­lites. In 2013 the Department of Defense launched its sixth WGS (Wideband Global SATCOM) com­mu­ni­ca­tions satel­lite and by 2019 the tenth one was put into ser­vice. The WGS is a six-ton satel­lite with a traf­fic han­dling capac­i­ty of 3.6 giga­bits. The first WGS went up in 2007, but that was six years after that was sup­posed to happen. The WGS sat design is under­go­ing a major upgrade that takes effect in the 11th one, which will launch in 2023. To com­ple­ment WGS there is the new ESS (Evolved Strategic SATCOM) and the first pro­to­types for these are sup­posed to be ready by 2025

WGS birds are opti­mized for mil­i­tary use and are more effec­tive than equiv­a­lent civil­ian comm satel­lites. WGS orig­i­nal­ly stood for “Wideband Gapfiller Satellite” and they are actu­al­ly mod­i­fied ver­sions of the Boeing 702 com­mu­ni­ca­tions satel­lite. Boeing has built or has orders for over 36 of the com­mer­cial 702s, which are built on the ear­li­er, and very suc­cess­ful, 600 series com­mu­ni­ca­tions satel­lites. Using the 702 as a model for WGS seemed like a slam-dunk ini­tial­ly, basing needed mil­i­tary commo birds on a solid civil­ian model. A few tweaks and addi­tions to deal with mil­i­tary secu­ri­ty needs, and off we go. The Department of Defense wants to build six WGS birds, at a cost of some $220 mil­lion each. The WGS has ten times the through­put (3.6 giga­bits) of the ear­li­er DSCS III commo satel­lites. The first WGS bird in orbit more than dou­bled the trans­mis­sion capac­i­ty of the Department of Defense satel­lite system.

This grow­ing need for more comm birds has been a prob­lem for decades. Between 2000 and 2002, Department of Defense satel­lite band­width dou­bled, and more than dou­bled every 18 months after that. Back in 2000, some 60 per­cent of Department of Defense satel­lite capac­i­ty had to be leased from com­mer­cial firms. While the Department of Defense had its own com­mu­ni­ca­tions satel­lite net­work (MILSAT), it under­es­ti­mat­ed the growth of demand. Greater use of the inter­net and recon­nais­sance air­craft and UAVs using video cam­eras quick­ly used up MILSAT’s capac­i­ty and forced the mil­i­tary to lease capac­i­ty on com­mer­cial satel­lites. This was done on the “spot market,” mean­ing the Department of Defense had to pay what­ev­er the market would bear at that moment. Since the mil­i­tary needed more capac­i­ty because of combat oper­a­tions, the media was also in the market for more capac­i­ty to cover the war. The Department of Defense paid more than ten times as much as it would have if it had leased (for one to fif­teen years) satel­lite capac­i­ty ear­li­er. The sit­u­a­tion was made worse by the fact that it was an emer­gency sit­u­a­tion, so every heavy user of satel­lite com­mu­ni­ca­tions was making their own deals. This result­ed in some users, like the air force, or, say, the Atlantic Fleet, having some extra capac­i­ty when some­one else, like Army Special Forces, was still short.

It was only in 1990 that the U.S. armed forces moved to satel­lite com­mu­ni­ca­tions in a big way. This made sense, espe­cial­ly where troops often have to set up shop in out of the way places and need a reli­able way to keep in touch with nearby forces on land and sea as well as bases and head­quar­ters back in the United States. At the time of the 1991 Gulf War, there was enough satel­lite mil­i­tary com­mu­ni­ca­tions capac­i­ty (com­mon­ly known as “band­width”) in the Persian Gulf for about 1,300 simul­ta­ne­ous phone calls. Or, 12 megabits per second. By the end off the 1990s the mil­i­tary now had a lot more satel­lite capac­i­ty, but demand had increased even faster. UAV recon­nais­sance air­craft use enor­mous amounts of satel­lite capac­i­ty, espe­cial­ly after September 11, 2001. The Global Hawk needed 500 megabits per second, and Predators and Reapers about half as much. The major con­sumer of band­width is the live video. Data trans­mis­sion capa­bil­i­ty had gone from 46 megabits (mil­lion bytes) per second in late 2001, just for troops in CENTCOM (the Middle East and Afghanistan), to nearly ten giga (bil­lion) bits per in 2007. Demand increased even more in the next decade This explains the rush to get those WGS type birds up.

Attempts to get capac­i­ty from civil­ian satel­lites was com­pli­cat­ed by the fact that there was a short­age there as well. This was cre­at­ed by the tremen­dous over­build­ing of fiber optic cable net­works on the ground (and under oceans) in the late 1990s. This pro­vid­ed cheap­er band­width for civil­ian uses and has meant fewer com­mu­ni­ca­tions satel­lites being put up. In fact, the fiber optic glut reduced planned satel­lite launch­es by some 60 per­cent for the first few years of the 21st cen­tu­ry.

The solu­tion was the WGS birds, with the first sup­posed to launch in 2004. But there were design prob­lems, man­u­fac­tur­ing prob­lems, and sched­ul­ing prob­lems get­ting an American launch­er (having a Russian or Chinese rocket put these birds into orbit was not an option, for secu­ri­ty rea­sons.) These prob­lems have been solved and while that pro­vid­ed more capac­i­ty it was never enough.

Strategy Page source|articles

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