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U.S. Army Radio Plan Leaves Soldiers Vulnerable to Jamming

Failing to address anti-jam capability of future radio would be a big mistake

10:37 GMT, February 24, 2012 Sometime over the next several weeks, the Army will release the final request for proposals in an effort to replace its ill-fated Ground Mobile Radio.

The radio was canceled last year due to price and performance problems, leaving a gaping hole in the service’s plans for future battlefield communications.

What the Army wanted was a vehicle radio that could connect with legacy systems already in the field while delivering new signals capable of supporting high-speed transmission of video, voice and data communications. What it got was a system too expensive and power-hungry to deploy in large numbers.

So now it’s back to the drawing boards with a new request for proposals that seeks similar high data-rate transmission capabilities in a more affordable package.

Somewhere along the way, though, the Army dropped a vital requirement -- and that could doom the whole effort. Specifically, it eliminated the anti-jamming capability for the most capable signal the new radio must support, which is known as the “wideband networking waveform.”

Jamming is the problem that arises when an electronic system can’t function because nearby transmitters interfere with the frequency on which it operates. Jamming is often used as a deliberate tactic to counter hostile radio or radar transmissions.

Other times it occurs accidentally, as with the recently rejected plan for a telecommunications network that would have degraded GPS signals.

The problem the Army faces in assuring connectivity between its units in wartime is that the modern battlefield is awash in potential sources of interference.

For instance, friendly forces generate a signal used to jam the detonators of improvised explosive devices that regularly interferes with communications systems transmitting in adjacent parts of the radio spectrum. If the interference is too powerful, it overwhelms the ability of radio receivers to operate the same way it negates the ability of insurgents to set off their bombs.

There’s an easy way to deal with this problem. It is an automated anti-jam capability that simply raises the power level of friendly communications signals when they’re in danger of being degraded.

A solution has already been developed for the wideband networking waveform that engineers call the “A/J mode of operation.” Not only does it prevent deliberate or accidental jamming, but it allows radios to communicate more effectively because they have additional power, for instance in dense urban conditions where signals can be dissipated or absorbed by obstacles.

Failing to specify this feature on whatever replaces the Ground Mobile Radio is a big mistake. It means soldiers dependent on timely, life-saving information carried on battlefield radios might lose their connection during the most dangerous moments of a fight.

Maybe omission of anti-jam capability for the wideband waveform was just an oversight, or maybe it was one of those penny-wise, pound-foolish economies that often are attempted when money is tight. Either way, it’s a decision that needs to be revisited before the Army starts handing out radios that could put thousands of warfighters at risk.