U.S. Army Faces Spectrum Crunch

Team Infidel

Forum Spin Doctor
Defense News
January 7, 2008
Pg. 1
May Run Out of Frequencies In 5 Years: Procurement Chief
By Kris Osborn
Within five years, the U.S. Army may have too little radio spectrum to allow its next-generation, networked force to work as it is being designed to do, the service’s outgoing procurement chief said.
Battlefield radio networks that allow friendly forces to exchange voice, data and video signals will be key to an Army equipped with 27-ton Future Combat Systems vehicles instead of 70-ton Abrams tanks. Even with Joint Tactical Radio Systems (JTRS) that move bits hundreds of times faster than earlier radios, the needs of an information-powered force are poised to overwhelm the available bandwidth.
“We have enough to do the job today, but I am not convinced we have enough to do the job I see coming five years from now,” Claude Bolton, the outgoing assistant Army secretary for acquisition, logistics and technology, said in an exit interview.
Beginning in 2010 and continuing for several decades, the Army will introduce elements of an ever-more-networked force that moves vast amounts of data from soldier-mounted sensors, aerial and ground robots, manned vehicles and more.
Bolton, who stepped down from his job on Jan. 2, said the Army is taking several steps to head off a communications crunch.
First, he wants a better sense of the magnitude of the problem. In December, Bolton commissioned the California-based think tank RAND Corp. to estimate his service’s bandwidth needs in 2012, 2017, 2022 and 2027.
“I commissioned a study because I think it is time to get real data, at least for the Army, because I could not find a study in the Department of Defense that gave me a database estimate of bandwidth requirements over the next 20 years in five-year increments,” he said.
Bolton also has asked the Army Science Board to look at the problem.
One area of promise is advances in compression technologies, which condense transmitted information to more efficiently use bandwidth.
“If you were collecting streaming video of a moving hostile target, you could dial up or dial down the data compression capability so that you are only able to view what you need,” said Loren Thompson of the Lexington Institute, a Virginia-based think tank. “The idea behind data compression is that you use only as much transmission capacity as needed to get the fidelity of messages you want to see. By tinkering with data compression, you can get much more carrying capacity out of available bandwidth than most people realize.”
But compression and even the new JTRS radios aren’t going to solve the Army’s bandwidth problems, Bolton said.
“Whether you ask me to compress, prioritize, or go to a different band, those are all Band-Aids. Eventually, you run completely out of bandwidth. Now what? I need that information,” he said.
One possibility, albeit long-term, may lie in the exotic world of quantum mechanics, where researchers are pondering methods of communication that use no radio transmissions at all, he said.
“My gut feeling is if we were allowed to come back in 100, or certainly 500 years, nobody would use electromagnetics and resulting bandwidth to communicate because it is a bankrupt approach,” Bolton said. “I don’t know if that particular technology is the answer. All I know is, we can’t go on with electromagnetics.”
Several physicists said there are early theoretical models now examining the possibility of using quantum physics to communicate information faster than the speed of light.
In the meantime, the Army is taking a pragmatic approach to the problem. Units that are testing out early versions of FCS technology at Fort Bliss, Texas, are pushing the new systems to their limits — but also practicing to see what they can still do when parts of the network go dead.
A soldier who gets used to fighting amid a wealth of information is hampered when that network goes down, according to a 2006 RAND study.
“Message latency (delay) affected warfighter effectiveness by as much as 50 percent for a selected scenario,” the study said.
Bolton said the Army is trying to figure how to fight with its new gear when it works as advertised as well as when it doesn’t.
“That is going to be the key to success in the future for us,” he said. “We want to red-team the network and see what happens if some of it goes away. That is exactly what we are going to do.”
Faster Radios
The next-generation JTRS radios move data far faster than existing radios. For instance, JTRS radios running the Soldier Radio Waveform can transmit several megabits per second, far more than today’s EPLRS (Enhanced Position Locating Reporting System) radios, which move several hundred kilobits per second, or the SINCGARS (Single Channel Ground-Air Radio System) radios, which move roughly 10 kilobits per second.
These new radios will give troops in headquarters, in vehicles and even on foot a huge advance in access to information.
“You can move maps and imagery as well as transmit voice and data with a tactical Internet capability, including higher data rates, anti-jamming and wireless networking capability,” said Howard Pace, JTRS deputy joint program executive officer for the Pentagon.
But networked waveforms, such as SRW and Wideband Networking Waveform (WNW), use more of the electromagnetic frequency spectrum than today’s radios.
“WNW is capable because we are using a large chunk of spectrum to broadcast at megabits per second with continuous bandwidth,” Pace said. “Now you are taking a piece of the spectrum that is already crowded, and you will be crowding more waveforms into the same spectrum.”
Pace said the Pentagon must move more quickly to retire older radios so that the newer ones can have electronic room to operate.
“If you don’t decommission some of these waveforms, you are trying to take more from something that is not there,” he said.
But Pace’s boss, JTRS joint program executive officer Dennis Bauman, said that’s going to take some time.
“Part of the force will still be using SINCGARS until we introduce the new capability, so at least until we get WNW and SRW across the force, SINCGARS is here to stay,” Bauman said. “But once you get it across the force, you should be able to phase out waveforms like SINCGARS and EPLRS.”
Nor can the Army look beyond its narrow segment of the spectrum.
Over the last two decades, the U.S. government has auctioned off to private companies many frequencies once reserved for the Pentagon, bringing in billions of dollars but constraining military communications.
Harvard University physicist Roy Glauber said the increasing use of frequency is a growing problem.
“The point is that every electromagnetic device uses a certain range of frequencies,” said Glauber, a 2005 Nobel laureate. “So every electronic device has a bandwidth, so if you have another device with an overlapping frequency band, you will get overlap and cross-talk. There is no alternative to having a bandwidth.”
Some Army officials see hope in the Air Force’s Transformational Satellite communications system, which will allow data rates of about two gigabits per second when it arrives around 2020, about eight times faster than the 250 megabits of today’s Advanced Extremely High Frequency Satellites. TSAT’s Internet Protocol-based system will also offer more flexibility than AEHF’s point-to-point connections.
 
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