Tactical Cloudlets: Mobile Computing Readies for Battle
During 14 years of war in the Middle East, Marines and soldiers came to rely on having ready access to computers. And the more capability they had, the more they wanted.
“What that evolved into was a tremendous demand for power and cooling that drove a need for fuel for generators,” said Kenneth Bible, the Marine Corps deputy director of C4 [command, control, communications and computers] and deputy chief information officer.
Fuel trucks became targets for insurgents, and defending them became an extra burden for troops. Clearly, a more efficient solution was needed.
Meet the “tactical cloudlet.” It brings the same concepts of distributed cloud computing to a remote and mobile battlefield scenario. The Marine Corps, Army, and university researchers are all working on the concept.
“We started to look at how we can start to lighten that load, particularly recognizing that the Marine Corps is heading back to more traditional roles” now that the heavy ground combat of Iraq and Afghanistan have come to an end. The Marines anticipate operating lighter expeditionary units that can respond to crises – from embassy evacuations to earthquake relief – in a matter of hours, Bible said.
Those units need computing power as soon as they land. But in order to maintain maneuverability, they need to keep light.
“If I can’t carry it, eat it, or shoot it, then I probably don’t want it,” Bible said. Except that the Marines do want forward deployed computing power, and “cloud computing looked like a great opportunity to lighten the load.”
But computing at the tactical edge is challenging even for the smartest of smart mobile devices. Connectivity there is often intermittent, and computers that are small enough to be highly portable lack the computing power and battery life needed for intensive data crunching.
Cloud computing relies on applications, storage, and computing power that resides not on limited local machines, but on networks of much more capable servers. Clouds enable “thin clients,” such as handheld devices with limited computing power, to tap into much greater computing capabilities via the Internet or other networks.
The Tactical Edge
Clouds work wonderfully well – until you get close to the tactical edge. In hostile environments such as battlefields and disaster zones, mission requirements change rapidly and the need for computing power is great, but communication is likely limited and access to a cloud is problematic.
Not so with cloudlets – they deploy with the troops. They’re just what their name implies – little clouds. They’re comprised of servers and communications gear engineered into small enough packages to be carried to the tactical edge.
To be most useful in combat, cloudlet components should be able to fit into a backpack, Bible said.
When deployed, a cloudlet would create a “communications dome” that stretches out 20 kilometers to 30 kilometers to provide cloud computing capability for “a company-level team” of up to nearly 200 troops, he said.
Communication for the cloudlet would be established by a mobile ad hoc network formed on the battlefield by smartphones, radios, micro nodes and other communications devices.
With the cloudlet in place, individual mobile computers would connect, offload data and assign computer-intensive tasks to the cloudlet, and then let the cloudlet do the work. Offloading saves battery power on the mobile devices, and it speeds up data processing by turning the job over to more capable machines – or in the cloudlet’s case, virtual machines.
Even though squeezed down to backpack size, cloudlet gear still must be powerful enough to work for troops on the move – in a helicopter, a V-22, or in vehicles moving on the ground. “We have some information that shows that we can do that,” Bible said.
The Army’s goal is to develop tactical cloudlets to provide soldiers with “the right information, at the right time, at the right place, and displayed in the right format,” says the Army’s High Performance Computing Research Center at Stanford University, where cloudlet research focuses on cloudlet formation and management.
Computer scientists are also working on tactical cloudlets for the Army at the Army Research Laboratory in Aberdeen, Md., and the University of Texas at El Paso.
The concept of tactical cloudlets is only a few years old. Much of the early work was done at Carnegie Mellon University’s Software Engineering Institute, and was based, in part, on an older but related technique called “cyber foraging.” In cyber foraging, resource-poor computers search for more capable computers or servers that are nearby and available to do the computationally intensive work.
Tactical cloudlets do the same thing, but in a more deliberate manner. Cloudlets place “discoverable resources” – servers and computers – at the tactical edge and make it easy for resource-poor mobile devices to find them, said Grace Lewis, a principal researcher at the Software Engineering Institute.
“When I say server, it’s the laptop – it could be a larger computer – but they’re basically forward deployed,” Lewis explained in a webinar on tactical cloudlets. “They are deployed in proximity of the people who use them. They can be hosted on vehicles; they can be hosted on other platforms,” and their job is to “provide an infrastructure in which to offload computation.”
After the cloudlet servers do the hard work, the lightweight handhelds harvest the finished product.
Cloudlets can serve other functions, as well, such as data staging, Lewis said. “So for example, if I know that I’m eventually going to use certain data on a mission, I can use these cloudlets to store this data so it can be available for me when I need it.”
And cloudlets can also be used for data filtering. “Let’s say I’m receiving a lot of information from the cloud or from the enterprise or from the data center. I could have these cloudlets do some pre-filtering on data such that on the mobile device I don’t receive a large amount of information, but I receive really just what I need,” Lewis said.
Cloudlets can serve as collection points for data that is gathered by troops at the tactical edge – photos, videos, incident reports, and other intelligence can be uploaded to the cloudlet and then forwarded to distant enterprise repositories when connectivity permits.
A key benefit of cloudlets is that they can continue to operate even when not connected to a larger cloud, a data center, or some other enterprise system.
With cloudlets at the tactical edge, “the opportunity is opened for us to get more intel, imagery and collaboration” where it’s needed on the battlefield, Bible said.
That won’t happen right away, though. “The technology is already there,” he said, but the doctrine lags behind. Cloudlets at the tactical edge aren’t a reality today, but they may be in about 18 months, Bible said. The tactics, techniques, and procedures need to be fleshed out, requirements generated, and the operational context identified in which tactical clouds are best used, he said.
Securing the Network
One feature of cloudlets that still needs more work is security.
“Our current cloudlet implementation relies on the security provided by the network; that is, a mobile device is allowed to interact with a cloudlet according to network policies and permissions,” Lewis said.
But that might not be good enough for tactical environments, she said. One possible solution is to use a third-party, online trusted authority to validate the credentials of those trying to use the cloudlet. But that could be problematic on the battlefield because the third party would not reside in the cloudlet, [and] thus would require online access, which isn’t always available at the tactical edge.
“Our future research will explore solutions for establishing trusted identities in disconnected environments,” Lewis said.
Bible said better security is “a question we’ve got to work through.” The answer probably includes a mobile device manager, he said – software that enforces rules regarding which users can have access to the cloudlet and what information they can access.