Compact military VSATs have big impact
Very-small-aperture terminals offer benefits that are fueling solid growth, but users must make tradeoffs
- By Terry Costlow
- Apr 13, 2012
Military tactics now focus on gathering lots of data and acting on it quickly with precision strikes. One of the important tools in this strategy is the very-small-aperture terminal, which has become so important that some observers feel the drawdown won’t significantly reduce its deployment.
VSATs have become a necessity for Special Forces, unmanned aerial vehicles (UAVs) and other entities that need small, lightweight equipment to be able to move quickly. Troops deployed in the mountains of Afghanistan and other regions, where transmission paths are often blocked by mountains and sandstorms, like the capability of lightweight terminals. The terminals also are seeing extensive use in UAVs, which need lightweight components to stay aloft longer. They contain antennas and transmitters which let aircraft communicate via satellites in the many instances where line-of-sight communications aren’t possible. As with man-portable products, size and weight are key issues in this deployment.
Budget cuts alter satcom plans
There’s concern that VSAT usage may not continue to expand in a time of major budget cutbacks. But many observers feel that these terminals, which are fairly inexpensive compared to most other satellite communication products, will be one of the last components cut by the spending axe.
The terminals have seen rapid deployment over the past few years. Market research from Comsys highlights the dramatic growth. At the close of 2010, the company set the number of installed VSATs at 1.4 million worldwide. But VSAT terminal orders for 2010 were more than double the installed base, at 2.9 million, according to Comsys.
“We do not anticipate VSATs decreasing in the field, even with the shift in focus from Iraq and Afghanistan to other conflict areas,” said Dan Losada, senior director of defense systems at Hughes Defense and Intelligence Systems Division. “That said, both the military and the intelligence communities will be looking to procure more advanced technologies and refresh their current VSATs to incorporate more bandwidth efficient solutions,” he added.
As warfighters ask for lighter, more compact systems that let them see real-time video, terminal developers are pushing technology in directions that often counter each other. Reducing power consumption and size are difficult alone. When increasing bandwidth becomes an additional goal, the challenge becomes far more difficult.
As design engineers move forward along these technical fronts, procurement officers are also trying to adjust acquisition policies so equipment can move into the field more quickly.
Another strength of VSATs is that they can be set up quickly. The military is also moving to make sure that VSATs can get through the procurement process quickly so terminals can get out to Special Forces and other users without lengthy acquisition cycles.
“The traditional acquisition process takes up to a five-year period, from identifying a need to fielding a solution. However, with VSAT systems, operational needs have been filled much more quickly,” said a Defense Intelligence Agency spokesman, who requested anonymity.
For example, TeleCommunication Systems' SIPR/NIPR Access Point (SNAP) is another program highlighting value of VSATs for the defense effort and demonstrating how quickly VSATs have become an integral part of military operations. These systems let warfighters work with three frequencies, Ku, Ka and X-band, using interchangeable modules that are lighter and more compact than three dedicated terminals.
“If an organization is able to use commercial off-the-shelf equipment, they can field VSATs in a matter of months or weeks,” the DIA spokesman said.
The rapid growth of UAVs is another driver for growth in VSAT usage. UAV usage has exploded over the past few years, and the drawdown in the Mideast isn’t expected to sharply curtail continued demand for more aircrafts and the terminals they carry. The shift from boots on the ground to eyes in the skies makes real-time communications with UAVs even more important. The terminals meet the size, weight and power requirements of aircraft, so they have seen rapid adoption as UAVs have moved into the forefront of intelligence, surveillance and reconnaissance technologies.
“We’ve seen very rapid uptake on airborne vehicles,” said Karl Fuchs, vice president of Technology for iDirect Government Technologies. “With the drawdown in Afghanistan and Iraq, there will be fewer boots on the ground. With the loss of intelligence assets on the ground, you’re required to have intelligence assets in the air.”
Size and Speed
Though VSAT usage is growing rapidly, the compact terminals aren’t a panacea. They can be deployed quickly, but once they’re set up, VSATs can’t match the performance of their larger brethren.
“There’s no free lunch, there are tradeoffs as you go to smaller terminals,” said Dwight Hunsicker, vice president of government services at Globecomm. “You need more power and bandwidth from the satellite to close microlinks. When you’re dealing with small equipment, to get 1 Mbit per second you may need 2 Mbits per second equivalent power coming off the satellite.”
Bandwidth on these smaller terminals is typically less than on larger units. Hunsicker noted that the broad global area network terminal, offered by mobile-satellite provider Inmarsat, is very small, both from the box perspective and from the capital expenditure side. But bandwidth for the terminal sold by Globecomm Systems is not designed for those with demanding applications -- offering a theoretical maximum of 400 kbits per second.
However, there’s a drive to improve the capabilities of compact antennas. One improvement involves moving to newer bands such as Ka and Ku. At the same time, improved communications techniques, such as time division multiple access (TDMA), help boost the amount of useful data that can be sent over a given amount of bandwidth.
“Multifrequency, deterministic TDMA (time division multiple access) lets us get 2 Mbits per second in the Ku band using a 12- to 18-inch antenna,” Fuchs said.
While these small terminals move to higher speeds, they are also becoming easier to deploy. It no longer takes hours for a specialist to get the antenna to point in the optimal position. Systems automatically focus on the most powerful signal.
“Auto alignment is great for comms on the pause, when you’re at a location for several days,” Hunsicker said. “If your requirements don’t change and you don’t move, it may make sense to send a technician out for the setup.”
Power to the People
Though VSATs are small and lightweight, terminal size alone isn’t the only factor that impacts their deployment. Battery consumption is a key factor, especially for Special Forces personnel and other troops who must carry batteries, terminals and other gear on their backs. Usage in the field is driven by both the footprint a piece of equipment requires and the amount of power it takes.
“Despite miniaturization of almost every component on a VSAT, power remains largely unchanged. Generators are large, fuel is scarce, batteries and power systems are heavy and are used up quickly,” the DIA spokesman said.
But that’s changing. Vendors are making improvements as they vie for market share. One key technique is to put components into sleep modes every millisecond that’s possible.
“Normally, when the modem is on, the block upconverter is on all the time, constantly drawing power,” Fuchs said. “We have a separate channel for the BUC (block up converter), powering it down when it’s not needed. The battery savings can be 30 to 45 percent. That’s huge for Special Forces and people on the move.”
Terry Costlow is a contributing writer for Defense Systems.