Wireless to the Nth Degree
Smart networks linking inexpensive devices will redefine network-centric warfare.
Wireless capabilities already have become an integral part of military operations. U.S. Marines practice foot patrols with a mounted data automated communications terminal, a tactical computer that connects to an enhanced position location reporting system for wireless Internet access. Using the system, Marines can communicate with each other while in convoys in current operations.
Envision a future filled with millions of wireless nodes connected through a smart network that automatically adjusts to optimize communications performance. Achieving this reality would require developing low-cost devices and mitigating current weaknesses in networking technology. However, when this vision is realized, troops will be able to infiltrate areas devoid of communications infrastructure yet stay in touch with each other and platforms in the battlespace.
The project that seeks to attain this goal is called the Wireless Network after Next (WNaN) program and is underway at the Defense Advanced Research Projects Agency (DARPA),
According to Preston Marshall, program manager, DARPA, the ambitious undertaking will develop and demonstrate technologies and system concepts that enable intelligent adaptive wireless networks. Hundreds, thousands, even millions of low-cost wireless devices will be connected through networking technology that adjusts its topology and the nodes’ operational mode to reduce the demands on nodes, particularly on the physical and link layers. Working as a collective, a multitude of devices can be more powerful than traditional networks that comprise a smaller number of large systems, he contends.
“Given that we have dynamic spectrum, that opened the opportunity to be very dynamic in how we form networks and how we form topologies,” he relates. “The basic theme that is running through a lot of our programs now is not to just hit a single performance point. It is to develop technologies that are very adaptable across performance regions and then to develop the technology to understand how to use and exploit that adaptation and still create networks that are stable, don’t thrash and are operable.”
DARPA’s second observation about the evolution of the wireless world involves the performance—particularly the fundamental limits—of radio frequency (RF) devices and how the devices’ usage is likely to grow. The researchers wondered whether these limits could provide insight into the form of future radios.
To explore this question, they performed a tuner study that revealed real limits to what can be done using highly linear RF equipment. As a result, they determined that they should be exploring strategies that depend more heavily on tunable filters. “We had to move from broadband filters to very narrowband tunable filters because we’re going to create denser and denser RF environments, and we’re going to be victims of the very environments we create,”
To illustrate the challenge that massive numbers of RF devices pose in the military sphere,
The goal of the WANN program is to demonstrate that a huge number of affordable devices can be built. If the DARPA team accomplishes this objective, it will begin examining the networking requirements to connect all of them.
Building these devices in mass and at a reasonable price is important to the military for a number of reasons,
|Lance Cpl. Bradley E. Ellis, USMC, multichannel radio operator, fixes an antenna receiver assembly on a troposphere satellite support radio. The radio allows units throughout the air base at Al Asad, Iraq, to maintain wireless communications with the tactical command center.|
One incidental benefit of smart, adaptable networks would be the elimination of the need for highly complex radios,
Although a lot of research has occurred in the area of identifying a topology that works well,
Because this approach depends on purchasing a large quantity of devices, cost is an important factor in its success. DARPA has set a price ceiling of $500 per unit, and
Once a device has been developed, the DARPA team can concentrate on the second component of the WNaN program, the networking part, which
Although the WNaN is a DARPA program in and of itself,
And achieving this synergy of programs calls for a fusion of another kind: cross-discipline collaboration. To facilitate this cooperation, DARPA conducted a workshop that focused on knowledge-based networking. The purpose was to bring the artificial intelligence and wireless networking communities together so they could learn from each other and pool their expertise. “We want people across disciplines that haven’t historically worked [very] collaboratively together because we really see networking and creating thousands to millions of devices as a fundamental problem and a big technology challenge,”
Creating these kinds of teams can be a lengthy process, he acknowledges. Examining different paths and various aspects of computer science and physics is what is needed, and no single specialty will be able to provide a solution for the devices’ design. The areas of networking, biology, cognition and many other fields “where we haven’t even scratched the surface to solve the networking challenge” may hold answers,
Wireless Network after Next program: www.darpa.mil/ato/solicit/WNaN/index.htm
Wireless Adaptable Network Node: www.darpa.mil/ato/solicit/WANN/index.htm
DARPA NeXT Generation Program: www.darpa.mil/ato/programs/XG