by DAVID AXE
Mountainous terrain like that in Afghanistan can block terrestrial radio waves, forcing soldiers to rely on expensive, technically complex satellite radios for their communications. As part of its ongoing next-generation network development, the U.S. Army is turning to a more than century-old technology to boost the reach of ground-based radios.
Aerostats — in essence, stationary airships — were developed during the Franco-Prussian War in the 1870s. More recently, the U.S. military and its allies have used tethered, 200-foot-long aerostats to loft surveillance cameras over bases in Iraq and Afghanistan. Aerostats are also part of a Pentagon missile-defense warning system called the Joint Land Attack Cruise Missile Defense Elevated Netted Sensor, or J-LENS.
Now the Army is adding radios to its aerostats, using them to “extend the network,” in the words of Army spokesman Paul Mehney. At a biannual Network Integration Exercise in New Mexico in July, the Army installed new software-defined radios in at least two aerostats. The airships helped push radio coverage into the mountains and valleys where thousands of soldiers were testing out new communications gear.
In a November iteration of the exercise, the Army employed three radio-carrying aerostats.
“The aerial layer allows RF [radio frequencies] to travel further and more freely. It gets you line-of-sight connections to additional nodes on the network,” said Jerry Tyree, an official from the Army’s Brigade Modernization Command. “We’re getting ranges greater than 60 kilometers with the aerial layer,” Tyree added.
For the July and November Network Integration Exercises, the Army selected two radio models for airship integration: the Boeing-made Ground Mobile Radio and the smaller Manpack radio, both designed under the auspices of the Joint Tactical Radio System program.
The vehicle-mounted GMR, developed since 1997 at a cost of nearly $6 billion, was canceled in October owing to increases in size and weight, poor reliability and the Army’s decision to buy more off-the-shelf radios. But Boeing has already built dozens of the 200-pound GMRs for testing; the Army is continuing to experiment with the design, as it is compatible with many of the new and existing radio waveforms that comprise the basic “language” of the branch’s emerging communications network.
In future iterations of the biannual network exercise, the Army is planning to also fit the aerostats with smaller Rifleman radios built by General Dynamics. With GMRs, Manpacks and Rifleman radios on-board, the aerostats will be capable of extending a network compatible with essentially all of the Army’s tactical waveforms.
Future exercises could also see greater use of miniature aerostats to help plug local gaps in radio coverage. At the November NIE, a small company called SofCoast tested out a roughly six-foot-long, man-portable airship called Mako that can carry cameras and small radios. “You can imagine how that would greatly improve your line-of-sight range for VHF and other types of radio communications,” a SofCoast representative said.
The Army has plans to send five Makos to a combat zone — Afghanistan, presumably — for more realistic tests.