The ultimate proving ground
During the past several years, the Defense Advanced Research Projects Agency, or DARPA, a unit of the U.S. Department of Defense, has devoted considerable resources to developing next-generation communications systems. Such systems promise to put cognitive, dynamic spectrum access, high-speed mobile ad-hoc networking and information-assurance in the hands of military personnel. All of this is being done as part of the U.S. Army’s Wireless Network after Next (WNaN) project.
While considerable progress has been made in the effort to make WNaN a reality on the battlefield, the gear needed to make it work is not being produced in mass quantities yet. However, the military plans to test communications technologies from at least two U.S. firms over the next several months that offer features desirable to warfighters. A bonus is that the technologies already are in product form.
One challenge the military often faces is the need to deploy communications systems quickly, particularly for the initial troops in a hostile environment or in areas where fixed networks are unavailable for a variety of reasons. To help address such problems, Sirran Communications has developed GSMNet, a solution that enables the rapid deployment of private cellular GSM networks in mission-critical situations.
Such concepts are commonplace in the commercial arena, with multiple vendors providing their carrier customers with cell-on-wheels (COW) solutions that can be hauled to a location where greater coverage or network capacity is needed. However, COW solutions are not ideal in battlefield situations, because they take considerable time to deploy, often require roadways that may not be available, and lack the kind of security needed for mission-critical communications, Sirran Communications CEO Brendan Reilly said.
“We’ve always worked in the tactical, military world, so we said we’re not building this for commercial customers,” Reilly said. “We’re building this for customers who want a higher level of security and for rapid deployment.”
During the past several years, Sirran has refined its tactical package to meet needs defined by its military users, Reilly said. The current GSMNet weighs just 20 pounds — it can be carried in a rucksack — and can be deployed by a single person in less than seven minutes, Reilly said. It is designed to operate with multiple power sources, allowing everything from military batteries to the commercial power grid to vehicle batteries to be leveraged to maintain communications, he said.
“For the same price as a COW, you can buy 20 units of ours,” Reilly said. “When you turn it on, it creates essentially the same capability as AT&T — an independent telecommunications infrastructure that puts out a network that covers approximately 30 square kilometers [18.6 square miles].”
As a telecommunications carrier, Sirran has roaming agreements with 367 carrier partners globally that use a GSM platform (either 2G or 3G), so it is able to support 86% of all cellular devices in the world, Reilly said. But the Sirran solution provides several capabilities that are not available on commercial networks, including stronger security measures and the ability to utilize federal government spectrum in the 1755–1850 MHz frequencies, which are in the GSM band.
In addition, because GSMNet utilizes government spectrum, the private networks established using Sirran’s solution can share users’ location data — something privacy laws prohibit commercial cellular carriers from doing, Reilly said. “You can turn a $20 flip phone into a blue-force tracker and … you are able to manage your resources efficiently, whether on the battlefield or in a [domestic location] after a disaster,” he said.
Also, the private GSMNet networks can be used to provide useful services to non-federal personnel as well, Reilly said. In crisis situations, the networks can be used to broadcast emergency alerts and other important messages to any GSM phone in the coverage area. Because the services are managed, recipients of the emergency message typically would not be able to reply to the messages. That’s a plus, because such ability could overwhelm the capacity of the network, he said.
Finally, the Sirran solution is simple for users. If commercial networks are down, the military-issued phones automatically will try to connect to a Sirran network using the federal government spectrum, Reilly said. Once a network is found, there is no need for special dialing procedures, he added.
“All you have to do is dial the colonel’s cell-phone number that you already know,” Reilly said. “And, although he’s deployed in the middle of a disaster zone on a tactical network from Sirran, his phone will just ring.”
Of course, the U.S. government has aggressive plans to make more spectrum available for commercial wireless use, and the 1755–1780 MHz frequencies located in the GSM band are one of the swaths being considered for this purpose. However, Reilly said that reallocating that spectrum for commercial use would be a mistake, because it would prevent the U.S. from utilizing the spectrum for a backup network that leverages cost-effective, readily available GSM infrastructure.
“I am lobbying and making sure that [reallocation of 1755–1780 MHz for commercial use] never happens … it’s a matter of national security,” Reilly said. “You have the ability for a fallback network. And the easiest to deploy, the cheapest and the most hardened — with 4 billion handsets out there — is a cell network. And the DOD controls frequencies that can be leveraged to do so.”
While Sirran Communications has been the subject of numerous military tests in the past, xG Technology is preparing for its first reviews from the U.S. Army, just months after making initial contact with the military. During the first half of 2011, the Florida-based startup will send its cognitive-radio xMAX equipment to Fort Monmouth, N.J., the laboratory facility for the Communications-Electronics Research, Development, and Engineering Center (CERDEC). In addition, a multisite xMAX system will be established in the desert training area of Fort Bliss, which is located in Texas and New Mexico.
Initially developed for commercial purposes, xMAX uses dynamic-spectrum-access (DSA) technology to avoid interfering signals. Although developed initially for the 900 MHz unlicensed ISM band, the xG solution is frequency agnostic. The fact that the xMAX system is able to assess the radio-frequency environment in a given location every 33 milliseconds and utilize airwaves that are open is an attractive characteristic to the military, which has been developing DSA technologies of its own — part of the coincidentally named XG project that is now part of WNaN.
New xG Technology CEO John Coleman said that this characteristic potentially would allow the military to leverage xMAX in even the most difficult spectral battlefield environments, where techniques such as jamming often are used. This is particularly true in the Iraq and Afghanistan theaters, where improvised explosive devices (IEDs) that can be detonated remotely using RF signaling have become a key tool for enemy forces, he said.
“As we have gone to ever-higher orders of electronic warfare to jam their firing chains, we’ve also created conflict and confusion within our own command-and-control system, because the things we’ve fielded interfere with the transport layers we’re trying to command and control our forces on,” Coleman said. “It’s an exceptional challenge just not to interfere with yourself.”
A properly designed cognitive network not only can avoid such interference, its ability to find and utilize open spectrum potentially could reduce the need for extensive spectral planning prior to making troop movements, said Coleman, a former U.S. Marine. These capabilities were enough to convince Coleman to leave his job with a defense-oriented company to join xG Technology last year.
“I ended up with xG looking to at their technology and wanting to basically partner with xG and I guess, in the process, I got captured,” Coleman said. “But I felt I could get the technology into the hands of the military faster if I was working inside the lines of xG than external to it.”
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