Data link lets even small UAVs serve as secure comm nodes

The Marines recently tested Harris’ system, developed in 90 days, on hand-launched Raven UAS.

Marines MQ 11 Raven UAS

A Marine launches a Raven UAS.


The Marine Corps has tested expanding its battlefield communications with a small, lightweight device that fits onto an unmanned RQ-11 Raven’s nose and extends secure communications well beyond line of sight for Marines in the field.

The Small Secure Data Link (SSDL), made by Harris Corp., is a wideband networking radio that, during the tests earlier this year during the Marines’ Talon Reach exercises in California, acted as a replay node for soldiers down to the squad level, according to an announcement from the company. And at 25 cubic centimeters (3 inches by 5.3 inches by 1.6 inches) and a weight of 18 ounces, it’s the smallest, lightest and lowest-power VHF/UHF software-defined radio certified for Secret and lower classifications.

Talon Reach was the first time the Marines had tested SSDL, which is based on Harris’ handheld Falcon III AN/PRC-152A radio, which the Marines, other services and Special Forces have been using for years, including as part of the Joint Tactical Radio System program.

Harris is making use of technology developed for other unmanned systems, such as the RQ-21A Blackjack, and applying it to the Raven, giving Marines long-range communications unencumbered by obstructions on the ground, Ed Zoiss, vice president and general manager for Defense Programs in Harris Government Communications Systems, said in a statement.

Raven UAS in flight

Serving as communications relays has been one of the primary functions of UAS over the years, in addition to their ISR (intelligence, surveillance and reconnaissance) duties. But it’s mainly been the province of large drones like the Air Force’s Global Hawk or even mid-size systems like the catapult-launched Blackjack.

But size, weight and power (SWaP) requirements for radios have put limits on what could be done with smaller drones like the hand-launched Raven. At 3 feet long with a 4.5-fopot wingspan and weighing 4.2 pounds, it’s not made to carry much of a payload other than its ISR cameras. It has, however, proved to be a popular tool with the Marines, Army and Air Force. The Marines, in fact, last year made training on the Raven part of the basic training for new officers.

Harris, building on existing technologies, was able to come up with a nose-cone design light enough for the Raven, as part of a process that took only 90 days, the company said. With a range of 6.2 miles at altitudes up to 500 feet, and flight durations of 60 to 90 minutes, the Raven can now help forces get around some of the limits of communications in contested environments.