The Federal Aviation Administration and the Federal Communications Commission spent two years -- from March 2009 to April 2011 -- locating just one GPS jammer used on the New Jersey Turnpike. That jammer interfered with an FAA system that provides enhanced navigation signals to aircraft in the vicinity of the airport for precision approach, departure procedures and terminal area operation

Dubbed as POLE-21, the system consists of jamming modules installed on mobile phone towers and working as a single whole to cover entire areas and making them impregnable to satellite navigation systems. Besides being powered by a towers circuit, the Pole-21 modules also use their 4G jammer antennas as a backup channel for signal control and transmission.

In the United States, eavesdropping devices are everywhere, and you have to carry a GSM jammer to protect your privacy. A GSM jammer was a type of device capable of blocking or fooling sensors. This could effectively cause a ship to go unnoticed by any possible observers, and also to prevent an attacker from gaining a weapons lock on the ship.

Your wireless home security system uses RF signals between your different sensors and the keypad to monitor your home. Each security system emits those signals at a specific frequency that is filed with the FTC. A portable jammer  simply sends out a super strong signal on the same frequency as your home system and causes white noise which effectively makes your system deaf to any alarm, such that the main panel cannot detect when a door or window is opened while the alarm is set.

According to American defense officials, the Russian military is deploying a weaponized form of GPS drone jammer that is effectively blocking some U.S. drone aircraft operations over Syria - and is even affecting drones equipped with anti-jamming technology. As more and more operators contemplate the deployment of autonomous vessels and aircraft in the maritime space, the vulnerability of high-specification military hardware to GPS jamming may pose a cautionary tale.

According to the U.S. Armys Asymmetric Warfare Group, the Russian military has invested heavily in electronic warfare gear in recent years, and its units "layer these systems to shut down FM, SATCOM, cellular, GPS, and other signals.” Russian forces have used these jamming capabilities before. During the Ukraine crisis in 2014, Russian forces grounded a U.N. surveillance drone fleet during operations in Eastern Ukraine using gps jammer, and Ukrainian forces reported widespread comms degradation. Last year, the U.S. Maritime Administration reported a GPS spoofing attack off the Russian Black Sea port of Novorossiysk, which caused the GPS displays on multiple merchant ships to show incorrect positions. The incident was not definitively linked to Russian forces, but reports indicate that it affected at least 20 ships.

Similar tests occurred in 2010, but Williams said Wednesdays effort was significant because wifi jammer technology has evolved, as have inmates efforts to smuggle in the devices. Such tests, she said, could lead to the broader use of technologies like jamming inside prisons to immobilize inmate phones, which officials across the country have described as their No. 1 security threat.

The renewed interest in jamming within federal facilities follows an announcement by Deputy Attorney General Rod Rosenstein, who told a national meeting of corrections officials that federal prisons would start testing the technology anew.