When thinking about satellite services that do not involve satellite phones, most envision receiving the data from a stationary satellite dish. However, General Dynamics C4 Systems recently demonstrated for the U.S. Army at Fort Gordon, GA, that a vehicle could receive Ku-band services while that vehicle is in motion.

C4 Systems said the system, named Satcom-On-The-Move (SOTM), is the first such system to be licensed by the Federal Communications Commission for use in the United States.

Developed under General Dynamics’ VertexRSI brand, the terminal “can sit on a commercial vehicle as well as a militarized vehicle to provide it with the beyond line-of-sight communications path that is needed,” Brent Finemore, director of strategic initiatives and business development for C4 Systems told Satellite News. He said the antenna is about 24 inches, or .6 meters and could end up smaller when the development process is finished. “We are trying to design a smaller one as we speak,” Finemore said. “We are just waiting to see if we can get the proper baseband equipment that would allow us to have a smaller antenna to work in the Ku-band.”

He noted the antenna is based on commercial off-the-shelf technology and uses software developed under the VertexRSI brand to help maintain links to the satellite.

“Basically, Vertex has a large library of control software for these types of systems,” Finemore said, noting that the control software has been used in the past on large earth stations and radars and required some modifications to ” allow the control system to work on a smaller, on-the-move type system.”

The control system allows the antenna to adjust to a variety of different environments. Finemore said the demonstration truck has maintained satellite connection at speeds of up to 50 miles per hour, but speed is not necessarily the biggest issue in terms of maintaining connectivity. “One of the biggest issues is how [the system reacts] when it is moving down a road and the signal gets blocked by trees or a building,” he said.

Additionally, the terrain also could cause connectivity problems. “It’s going to be the terrain and how large the bump you go over or the ditch you go in that could cause your vehicle to rock left or right” and break the antenna’s connection with the satellite. “One of the major factors to being able to build a ruggedized terminal is the control software and the ability to tell the antenna to move to stay locked on the satellite. Those are some of the things that the network engineers have to address.”

Complementing Other Services

The SOTM system as it stands now comes with a price tag of roughly $300,000, though Finemore attributes that cost to the fact that the system is not in general production. But that should not necessarily intimidate potential buyers who may benefit from the service.

“If someone looks at what it costs to buy the terminal, it’s a one time cost,” Finemore said. “Then you start buying Ku-band capacity, which is relatively cheap.”

He compared the costs to other services on the market, such as those offered by Inmarsat, where terminals can be bought for $3,000, but air-time charges boost the cost of using those terminals significantly.

“The Army has had millions of dollars in bills for L-band usage,” Finemore said. “The military is looking at that. It may cost a little bit more for the hardware to have the terminals out there in the battlefield. But when you start using it 24 hours a day, seven days a week, which [the military wants] to do, and when Inmardat costs $7 to $9 a minute every time you bring it up, it really doesn’t take long to pay for that [$300,000] terminal.”

But Finemore said the goal for this product is not to take marketshare away from Inmarsat. “If a military or commercial user wants broadband on demand in a rugged environment and they want it all the time, then Ku-band is your answer,” Finemore said. However, “there are times where L-band is better suited, such as when the need is for small data requirements or access over the ocean in places where one may not get good Ku-band coverage. You may see some guys who want both so if you had a Ku-band blockage issue or a bad weather issue where you are having trouble linking to the satellite, you could connect to an Inmarsat terminal and get at least limited capacity.”

And given the potential addressable market on the military side, demand from that alone could push the price tag down.

Based on the Army’s new Warfighter Information Network-Tactical (WIN-T) program alone and other Army initiatives, “the numbers get into the hundreds of on-the-move points of presence out on the battlefield, so there is a significant opportunity out there,” Finemore said.

But the opportunities are much more limited on the commercial side. Finemore said C4 Systems has seen some interest in the technology from some commercial entities, particularly news gathering agencies. But developing a scaled-down version for more widespread consumer use is not on C4 Systems’ agenda at the moment.

“This terminal has been designed and geared to military requirements,” Finemore said. “It is in our interest to come up with a lighter, less capable terminal to introduce to the [commercial/consumer] market? I would say it is a tough sell because you would get very limited capacity. It’s something we have to consider, but we are really focused on the military market, which has significant growth potential.”

–Gregory Twachtman (Fran Jacques, C4 Systems, 480/441-0342)