DEFENSE DEPARTMENT

Mobile Broadband for Roaming Troops: Pipe Dream or Reality?

6/1/2008
By Sandra I. Erwin

In the world of high-tech military communications, troops fighting on the front lines are known as the “disadvantaged users.”

The tech-deprived troops typically are driving around in humvees and patrolling on foot. They have little to no access to the Internet and their ability to communicate is largely limited to line-of-sight radios.

In recent years, the Defense Department has spent billions of dollars on mobile satellite-based communications to bring connectivity to forward-deployed troops. But the available systems are scarce and too expensive for the military services to be able to field in large quantities.

Military officials insist that next-generation technologies — such as satellites that beam data via lasers and miniaturized antennas that can pick up signals from multiple satellites — will deliver the high-bandwidth networks that troops need. Some of these key technologies, however, are still on the drawing board or in the early phases of development. It also remains in doubt whether the Pentagon can build these new communications systems at a reasonable cost.

Satellite-based communications, or sat-com, have been critical to military operations for decades. But only recently has the demand for mobile, high-bandwidth networks exploded as the military has become more dependent on streaming video, imagery and digital maps. For that data to be useful, they must be available in real time, which requires fast, high capacity communications pipes. Most sat-com systems currently deployed are made up of bulky terminals and large dishes. They are not easily transportable, so they are set up at military bases or command centers. Smaller mobile systems currently are used aboard some larger Army vehicles, such as the Stryker armored personnel carrier.

But the Pentagon has yet to figure out how to make mobile sat-com systems more widely available to the entire force, especially soldiers who patrol war zones in humvees around urban areas where line-of-sight radio signals are blocked by buildings.

Under a project known as “war fighter information network-tactical,” or WIN-T, the Army is expected to sort out the technical requirements for mobile networking. Industry experts say the military’s demanding goals for lighter, portable technology can only be met with a hybrid system of satellite communications and wireless terrestrial networks.

The Government Accountability Office concluded in a recent audit that the Army’s wished-for mobile network “is largely to be invented at this point” as the technology is not currently available.

Some industry experts agree that the mobile sat-com systems the military wants do not yet exist — the technologies are not mature enough and the components are too bulky. They also suggest that the Pentagon’s traditional approach to buying hardware is unhelpful for systems such at sat-com networks, which require the integration of components made by different vendors.

While sat-com “on-the-move” systems are plentiful in the commercial non-military market, they do not necessarily adapt to military requirements. The most significant difference is that civilian users do not require connections to the Pentagon’s secure encrypted satellites. While a commercial sat-com system may have a single dish pointing to one communications satellite, the military is seeking multi-band systems that connect simultaneously to more than one satellite from a moving vehicle. The military, for example, wants sensitive information to be restricted to classified EHF (extra high frequency) satellite channels. But because those pipes have limited capacity, users want to also shift less-sensitive data to other higher-capacity commercial satellites. Such a setup today would require multiple dishes or phased array antennas, which would be cumbersome to operate from a moving vehicle.

With the technology that is available today, the military could achieve multi-satellite communications “on the quick halt,” but not on fast-moving vehicles, says Richard Hitt, president and CEO of Hypres Corp., a supplier of superconducting microelectronics that are used in government and commercial communications networks.

“On the quick halt” is military-speak for systems that can be set up relatively quickly, maybe in about 30 minutes, says Hitt. “That technology exists. It’s not elegant but it can do the job.”

But consolidating a host of moving parts into a single piece of equipment that works from a moving vehicle would be almost impossible with current technology, Hitt says. The data-transmission speeds that the military wants demand large antennas that cannot realistically be operated from already overpacked humvees, he adds. “The commercial sector doesn’t have those requirements.”

Another obstacle for military systems is the Defense Department’s “stovepipe” approach to developing technologies. Each component of a sat-com system typically would be built by different military organizations or contractors.

“You have stovepipes in sat-com that are tough to integrate,” says Hitt. Each band requires separate antennas, amplifiers, converters and other pieces of gear that collectively would make for a heavy load.

In the higher frequency bands, the only way to package such a wide array of components into a mobile system is with some type of multi-band phased array antenna, Hitt says. “There is technology, but it’s terribly expensive. The antenna would cost more than the vehicle it’s on,” he says. “There are a few versions around but they are not as multi-band or as high data rate as military users want them to be.”

Adding to these challenges is the uncertain future of the Defense Department’s vaunted “transformational satellite,” or T-Sat constellation.

T-Sat was conceived as a protected, EHF wideband sat-com system that relies on high-speed optical, or laser, cross-links among the satellites. Its main goal is to provide Internet protocol network routing and communications-on-the-move services. T-Sat would deliver data significantly faster than the military satellites that are in orbit now, according to the Air Force.

Supporters contend that the program is critical to the Pentagon’s goal of shifting its communications — voice, video and data — to IP-based networks, which ultimately could help ease the military’s bandwidth crunch.

But escalating cost estimates for T-Sat and questions about the need for such a complex system could sideline the project.

“T-Sat will be challenged,” says a senior Air Force procurement official during a private meeting with contractors. “I don’t get warm vibes when T-Sat comes up,” he says. “The technology is there, but do we really need it?”

The Air Force and the Defense Department are considering plans to possibly downscale the T-Sat program or even replace satellite links in the military’s “global information grid” with terrestrial or aerial routing alternatives.

Even if T-Sat survives, the satellites would take 10 to 15 years to build. Such a long development cycle raises questions of whether the money should be spent on more mature technologies, even if they are less sophisticated.

The Pentagon is building an “advanced EHF” satellite constellation that is considered a short-term fix, but would still not provide enough capacity to replace T-Sat in the long run.

The current EHF network is not adequate for today’s demands, Hitt says. “Critical data move over EHF today, but it’s over relatively narrow beams,” he says. “T-Sat is supposed to fix all that, and provide true wideband high-data rate protected EHF.”

The broadband capabilities of T-Sat — especially video and voice-over-IP — will be tough to replicate with other systems, say industry experts. A new wideband global sat-com (WGS) spacecraft that the Air Force recently launched offers more capacity than current satellites, but only EHF birds are considered secure enough for classified communications.

The Defense Department also is deploying a new ultra-high frequency satellite constellation for sat-com on the move, but bureaucratic snags have delayed the production of radio terminals. It could be several years before large numbers of digital UHF terminals are available for the entire force. Another concern is whether the new UHF satellites will offer wide enough bands to deliver streaming video and data in addition to voice communications.

A larger issue that is slowing down the deployment of mobile broadband services is the military’s poor understanding of what is available in the commercial sector, says Richard A. Vandermeulen, vice president of government broadband at ViaSat Inc., a supplier of communications technologies.

He concedes that the commercial sector doesn’t have every single technology that the military desires, but insists that most requirements could be met by the sat-com industry if the Defense Department clearly articulated what it wants. “There might be a disconnect within their knowledge of what they want versus what exists,” he says. “The commercial market is ahead of where the government thinks it is.”

Companies such as ViaSat and Hughes Network Systems have produced systems that function on the move, Vandermeulen says.

It is conceivable that if T-Sat dies, the Defense Department could acquire comparable capabilities from the commercial sector, he says.

Cisco Global Government Solutions Group is developing an Internet router protocol in space (IRIS) payload that will be tested aboard a commercial Intelsat communications satellite.

The company says it plans to demonstrate the viability of conducting military communications through an Internet router in space, similarly to what T-Sat would do.

The Pentagon selected IRIS as one of seven “joint capability technology demonstrations” in 2007. It will be a three-year project, according to Intelsat. Space Systems/Loral will manufacture the satellite scheduled to carry the IRIS payload, which is scheduled for launch in 2009.

The IRIS project has spurred debate within the sat-com industry about the merits of IP-packet switched satellite systems compared to traditional transponder satellites, which receive signals and send them back to Earth, where the ground network routes the data.

Hughes recently began to offer IP networking services on Spaceway III, which is a switched-payload satellite like T-Sat, Vandermeulen says. This technology is considered to be more flexible in handling call traffic, but the industry has not yet been entirely convinced that the added cost of the technology justifies its benefits.

Only a handful of satellites in the commercial sector offer IP-packet switched services while hundreds provide traditional transponder-based communications. “The commercial market is trying to determine which is best,” he says.

Processing data and routing calls in space are expensive undertakings, Vandermeulen says. “It’s not clear if that added complexity has an equivalent improvement in marketability.”

The main benefit of satellites that don’t send signals back to Earth is that they can more easily be reprogrammed to provide communications services anywhere in the world, depending on where the customers are located. The military typically prefers satellites that are cross-linked (like Milstar) in case there are problems processing signals on the ground during wartime.

“For the military, switching in space may make a lot of sense,” he says. But many executives in the sat-com industry have questioned whether there is a compelling need in the commercial market for satellites that are cross-linked and switch data in space. “There are some advantages but it’s not clear that they outweigh the complexity and cost,” Vandermeulen says.

One of the most compelling arguments in favor of cross-linked satellites is that they move data faster because the signals are not traveling up and down.

But that rationale is debatable, says Vandermeulen. The reduced latency may not benefit all users of the network, he says. If a user is connected via a transponded satellite and also connected to a ground terrestrial network, the signal would only go over the satellite once. But if he is connecting to another satellite user, that traffic would be improved by switching in space, he says. “It’s not clear what percentage of the traffic benefits from switching.”

Also a matter of controversy in the industry is whether the Defense Department underestimates the level of encryption and information-security that is offered by commercial sat-com systems.

“That all depends on what you consider the threat,” Vandermeulen says. “Milstar [the current EHF classified satellites] were designed to survive nuclear war … Commercial systems will never be hardened against nuclear holocaust.” But commercial systems are used by major corporations and are hardened against cyber-threats. Higher-end commercial services can provide military-level encryption. Financial institutions and other organizations that cannot afford intrusions rely on these systems, he says. “There’s a degree of ruggedness … It’s not a black or white question.”

Please email your comments to SErwin@ndia.org

Topics: C4ISR, Tactical Communications, Space

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