One of the big changes in the American military in the last decade has been the emergence of the battlefield Internet. This can be seen by the growth in the number of radios (nearly tripled, to over 900,000) and the increase in data transmission capability (bandwidth) from 46 megabits (million bits) per second in late 2001, to nearly ten giga (billion) bits per second now. This is just for troops in CENTCOM (the Middle East and Afghanistan). Thats 200 times more data being pushed through three times as many wireless devices (radios). This doesnt even count the many cell phones and laptops used by troops in the combat zone, which often use civilian bandwidth.
The major consumer of all this new 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. This huge growth 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 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. 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. At the moment, the U.S. has far more demand for satellite communications than it can support. As a result, not all the Predator and Global Hawk UAVs in combat zones have sufficient bandwidth to send their video back to the United States. Data compression and using lower resolution is 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.
While the larger UAVs need satcomm to send video back to the United States, most of the bandwidth demand now is for local use. Tanks, helicopters and aircraft are all sending and receiving more vids, maps and data of all sorts. The combat Internet is hardly identical to the civilian one, but the basic idea is the same; to keep everyone connected, all the time. More radios, and other wireless devices are on the way, as well as more features any Internet user would recognize, all available while under fire.