March 28, 2016: European aerospace firm Airbus recently signed a $160 million contract to manage two German MILSATS (military communications satellites) through 2022.Airbus has already been doing for the German military this since 2006. The two satellites (COMSATBw1 and COMSATBw 2) are relatively new with one becoming operational in 2009 and the other in 2010. Each weighs 2.4 tons. Airbus will manage the ground stations and the ability of German land, air and sea forces anywhere on the planet to communicate with each other and anyone else via analog (voice) or digital (for anything). These encrypted links also provide access to the Internet.
These two German satellites are similar to the six larger (six ton) American AEHF (Advanced Extremely High Frequency) satellites in orbit. The first AEHF satellite was launched in August 2010. Like the German satellites it uses a permanent fixed 36,000 kilometer orbit. Like most current communications satellites AEHF was built to last 14 years. AEHFs replaced the older MILSTAR birds, providing more abundant and reliable (jam-resistant) communications, just like the two German satellites.
Germany is finding that, like the Americans, the major consumer of all the additional bandwidth is live video being generated by the increasing number of vidcams on the battlefield. These vids are being exchanged by the units cooperating in an operation, be it combat or peacekeeping. This huge demand for in bandwidth began in the 1990s, when the U.S. armed forces moved to satellite communications in a big way. This made sense, especially where troops often have to quickly 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 bandwidth in the Persian Gulf for about 1,300 simultaneous phone calls (12 megabits per second).
But while the military has a lot more satellite capacity now (the exact amount is a secret), demand has increased even faster. UAV reconnaissance aircraft use enormous amounts of satellite capacity. The Global Hawk needed 500 megabits per second and Predators about half as much. The major consumer of bandwidth is the live video. UAVs have other sensors as well, as do aircraft. A voice radio connection only takes about 240 bytes per second and each of the multiple channels needed to control the UAVs use about the same. But it adds up, especially since the military wants high resolution video. Until recently (when the AEHF birds went up) the U.S. had far more demand for satellite communications than it could support. As a result, not all the Predator and Global Hawk UAVs in combat zones had sufficient bandwidth to send their video back to the United States. Data compression and using lower resolution was often necessary or using satellite substitutes (aircraft carrying transponders) to send the video to local users. The substitutes are becoming more common, simply because there is neither the money, nor the time, to get sufficient satellites into orbit.
Germany has been adopting the same type of equipment the Americans use in part because they know it works in combat and in part because all NATO nations try to adhere to common standards for basic gear, like communications systems.
No comments:
Post a Comment