WiFi jammer devices will be a new weapon in electronic warfare

The Navy sent to Iraq hundreds of electronic warfare specialists, to bring the cacophony produced by 14 kinds of jammers into some sort of harmony. Protocols were established, to allow one device to send its signal and then go silent for a few milliseconds, so another gadget could broadcast; that allowed Warlock Red and Warlock Green to be packaged into a single, combination unit...The intelligence specialists at the Combined Explosive Exploitation Cells got faster and faster at analyzing which frequencies the insurgents were using. That, in turn, allowed the jammers to be updated more quickly, so they could counter emerging threats.

The North Koreans are believed to possess a mix of old Soviet jammers, purchased roughly 10 years ago, and their own homemade equipment. These jammers on wheels are positioned in Kaesong province hilltops around the border for maximum reach, Last said.

A new generations of jammers were introduced too, they could cover a broad range of frequencies and perform specific "set-on" jamming which mean that "rather than confuse a receiver with a modified version of its own signal, Duke had a series of built-in jamming responses, designed to fool very specific devices." And as jammers got better, the insurgents in Iraq largely abandoned the use of IEDs and deaths from IEDs dropped.

Reasons for using jamming devices

Military jammer, known as Counter Radio Controlled Improvised Explosive Device Electronic Warfare, or CREW systems, attempt to intercept or block a signal before it reaches its intended target, preventing detonation.

One common method is barrage jamming, which knocks out a broad range of radio signals. However, it also knocks out communications used by U.S. troops putting them at increased risk.

Jamming involves pumping out RF in the frequency range they are using enough to overpower their own signals. So, you need power and you need to know the frequency range. Since RF drops off as the square of the distance, unless you can aim it very carefully, you have to be close or have lots of power. They don’t really publish exactly where it is you need to point, so go with needing lots of power.

In principle, yes. But modern frequency-hopping technology makes it very difficult, because the jammer can’t predict what frequency will be used from one moment to the next. The only practical approach is a broad-band assault on the entire frequency range, which requires a very large amount of power.