August 9, 2013
Demand Grows for Broadband SATCOM Links to and From Aircraft
When they look ahead, satellite communications firms expect the US reliance on special operations and vigorous diplomacy to drive a demand for airborne satellite communications far beyond the unmanned aircraft collections that turned SATCOM resellers into millionaires during the wars in Iraq and Afghanistan.
The Obama administration has established a small-footprint, active foreign policy. Special operators will need to reach back to intelligence troves and plan missions on the fly. Diplomats will demand mobile connectivity with embassies and the State Department in Washington. Government VIPs, including the defense secretary and staff, will want broadband while flying around the world, sometimes in special VIP pods rolled into the bellies of C-17s.
“All of that speaks to having beyond-line-of-sight, in-transit communications and a range of communications from narrow to broadband,” said David Helfgott, CEO of Inmarsat Government, which provides SATCOM to the U.S. government.
Companies including Inmarsat Government of Herndon, Va.; ViaSat of Carlsbad, Calif.; and Xtar, also of Herndon, are vying to meet the demand with a mix of frequency bands and new kinds of communications terminals. They’re convinced that government communications satellites, including the Ka- and X-band Wideband Global Satcom spacecraft, won’t be able to do it all.
In fact, Inmarsat and ViaSat plan to compete in the Ka-band frequency range. Ka signals are higher power and frequency than today’s widely-used L and Ku commercial bands, which means they can send more data to the small antennas required for aircraft applications. Ka is great for broadband applications such as high-definition video and imagery, or when capacity must be diced up among numerous users, such as in an airliner. Whereas L and Ku top out at data rates of about a megabit per second, Ka can transmit tens of megabits per second. The tradeoff is that Ka signals are prone to fading in the rain
ViaSat, known for building modems and for arranging Ku-band services through satellites operated by other companies, now has big plans for the Ka market. It’s working with JetBlue to launch an in-flight passenger broadband service later this year called Fly-Fi, which will use Ka-band capacity from the ViaSat-1 satellite launched in October 2011. The company plans to launch a second Ka satellite, ViaSat-2, in the next couple of years. Both will be placed in geosynchronous orbit to service North America, Central America, the Caribbean, the Atlantic Ocean and Hawaii in the case of ViaSat-1.
ViaSat plans to take Ka into the military market, too, but without supplanting Ku any time soon. The Ka geographic coverage will be too limited. Instead, ViaSat wants customers inside C-130s and C-17s to be able to transition seamlessly between Ku and Ka comms. It’s developing what it calls a Kukarray — Ku and Ka antennas installed on a mechanical platter inside a single radome.
“Over time, we are going to offer a hybrid service that will allow large platforms like the C-17 to operate in our Ku-band network and, where possible, over our Ka-band satellites,” said Paul Baca, ViaSat’s vice president and general manager of global mobile broadband systems.
To date, ViaSat has arranged Ku-band satcom on 15 C-17 transport planes. It wants a larger share of the 100-plus plane fleet. C-17s aren’t just for carrying equipment and troops around the world, Baca said. When the defense secretary wants to travel “incognito,” workers can load command-and-control VIP pods into the belly of a C-17, he said. C-17s also deliver special operations forces where they need to go.
As exciting as Ka-band is, ViaSat knows it can’t ignore the Ku-band network it has crafted by forming partnerships with other satcom providers. “We’ve recently made a significant investment in improving that Ku network, adding a lot more capacity in the areas most traveled primarily by airborne customers,” Baca said.
For its part, Inmarsat operates nine L-band satellites, but plans to get into the Ka-band market, too. The company said it thinks it’s pushed L-band about as far as it can with the 1.3 megabit-per-second data rate available over the company’s Swift Broadband airborne equipment.
Inmarsat plans to launch three Ka-band satellites to establish coverage around the world, except the polar regions, by late 2014 or early 2015. “As the [intelligence] payloads have gotten more complicated and bandwidth dense — multispectral high-definition imagery and stuff like that — it’s really become a huge demand driver,” said Inmarsat’s Helfgott. The company hopes to launch the first satellite in this Global Xpress constellation this year, although a July Proton launch vehicle explosion could put a wrinkle that plan.
Like ViaSat with its Ku-band services, Inmarsat has no plans to give up on L-band, which is available globally — aside from the polar regions — and whose signals don’t fade in the rain as Ku and Ka bands do. Inmarsat has an agreement with the European Space Agency to operate Europe’s soon-to-be-launched Alphasat spacecraft, which will provide L-band to Europe, the Middle East and Africa.
There are always trade-offs when it comes to SATCOM. X-band, a frequency range that the International Telecommunication Union reserves for governments around the world, is similar to commercial Ka-band in that it provides multiple megabits per second of throughput but tops out at about 10 megabits per second when conditions are just right. “There’s one thing that’s clear about the satellite industry: Not one shoe fits all feet,” said Philip Harlow, president and chief operating officer of Xtar.
The service is installed on about 20 different types of small, piloted planes equipped for airborne intelligence, surveillance and reconnaissance collections. The U.S. and its allies are the customers.
“Where X-band fits in, and fits in so much better than any other frequency band, is on those operational requirements which just simply cannot afford downtime and simply cannot afford to have large dishes on board,” Harlow said.
Aircraft can carry small dishes 30 centimeters across because “there’s no adjacent satellite interference of note to worry about,” he said. The commercial Ku satellites, and soon the Ka spacecraft, are packed together in orbit, he said. On top of that, X-band doesn’t suffer the rain fade problem, Harlow said.
“Losing connectivity with a platform that is providing real-time intelligence cover, where timing is critical and potentially human lives are on the line, is simply not an option,” he said.