ARLINGTON, Va.--When warfighters need to send covert messages over military wireless networks, they cloak the transmission signals in a haze of virtual "noise" or chatter. This method hides secret communications effectively, but also consumes immense bandwidth, limiting message size and speed.
However, thanks to the efforts of a computer scientist sponsored by the Office of Naval Research (ONR), military wireless networks could one day be larger, faster and accommodate more users.
For his work on network information theory--which seeks to determine how many users and devices a wireless network can support--Dr. Syed Jafar, a professor at the University of California, Irvine, recently won the 2015 Blavatnik National Award for Young Scientists.
"Dr. Jafar has conducted game-changing research in the study of wireless network capacity," said Program Officer Dr. Satanu Das, who works in ONR's C4ISR Department. "This has helped us explore new frontiers in bandwidth efficiency for military communication networks."
The Blavatnik awards are presented yearly by the New York Academy of Sciences, honor the nation's most exceptional scientists and engineers under 42 years of age, and provide a prize of $250,000 to each winner. Jafar was one of three winners chosen from among 300 candidates.
Jafar's award-winning research determines how much user capacity a wireless network (a series of signal transmitters and receivers) can hold. With the rapid growth of--and need for--civilian and military wireless networks, this knowledge quest has taken on unprecedented urgency.
Wireless networks have a limited, or fixed, amount of bandwidth and user capacity. When just a few people are online, signal strength is great, but when more users connect, the connection slows down.
"Take a network that can support 20 users, for example," said Jafar. "It's loud, chaotic and everyone is talking at once, creating interference that diminishes connection strength."
To remedy this, wireless providers usually divide available bandwidth into slices, like a cake. The more users, the smaller the bandwidth ration for each. The problem, said Jafar, is this method has never been proven to be the most effective or efficient.
Through his research, Jafar has found that--by changing the mathematical formulas and algorithms used to design wireless signals--it's possible to potentially filter out undesired signals at every network receiver, making other users' interference less intrusive while allowing each user to access half of the total bandwidth free from interference.
"This means that, in a network of 20 users, each person's available bandwidth can increase by a factor of 10," said Jafar. "In theory, everyone gets half the cake instead of one-twentieth. This principle can apply to networks of varying sizes."
Altering the signal design formulas also naturally jams undesired signals, guaranteeing communication security, since only desired signals are visible at each receiver.
Although Jafar points out his research is still theoretical and needs further testing, his work has influenced the overarching conversation about how people understand wireless networks and the best way to design them.
"This also could benefit the work ONR does, since the military is always seeking information advantage," said Jafar. "By increasing its wireless network capacity, the military can accommodate more users, send out stronger, more secure covert transmissions and more effectively jam incoming hostile signals."
Jafar's work aligns with several tenets of the Cooperative Strategy for 21st Century Seapower, a maritime strategy shared by the U.S. Navy, Marine Corps and Coast Guard. The strategy calls for increased focus on cyberspace operations, which includes defensive and offensive measures to protect networks and data.