Radio frequency jammers that prevent improvised explosive devices from detonating via remote control have been employed for years in battlefields to prevent roadside bombs from exploding.
First responders use the devices as well. The problem is that they suppress all communications in their transmission zones, which wreaks havoc on police, fire, and bombs squads, which need open lines of communication.
The 2008 London transportation system bombings prompted a British firm, Kirintec Ltd., to develop a tent-like structure that can be placed over a suspicious object. The Rebus jammer system cuts off outside signals that could be used to set off a bomb while preserving radio communications.
“First responders can continue to communicate with each other while still having all the RF protection,” said Chris Haggerson, a sales associate at the company’s U.S. office.
The tent itself is made with copper mesh material which helps contain the jamming signal. A broadband antenna focuses it inwards. There is some signal leakage, but only within a foot or two of the device, he said. “Ten feet away, there is absolutely no effect on communications,” he added.
The foldable tent allows first responders to buy time while they wait for explosive ordnance disposal technicians to arrive on scene.
The London Transport Police have purchased some of the systems in preparation for the 2012 Olympic London Games. The Navy Explosive Ordnance Disposal Tech Division and the office of the secretary of defense’s Technical Support Working Group are testing the system, Haggerson said.