America is increasingly using jamming as a common technique

Federal prisons officials on Wednesday tested a jamming technology inside the walls of a federal prison, a rare move that authorities said they hope will help combat the danger posed by inmates with cellphones.

Similar tests occurred in 2010, but Williams said Wednesday’s effort was significant because gps 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.

Communication jamming devices were first developed and used by military. This interest comes from the fundamental objective of denying the successful transport of information from the sender (tactical commanders) to the receiver (the army personnel), and vice-versa.

The U.S. military is worryingly dependent on GPS. Our global positioning satellites tell planes where they are, provide targeting info for smart weapons, and support communication and navigation systems. But in a war with a tech-advanced adversary—think China, Russia, or Iran—GPS could become a big liability because it could be signal jammer, spoofed, or outright destroyed.

If South Carolina prisons were able to use cellphone signal jamming technology, an inmate would not have been able to escape from a maximum-security prison last Tuesday, state officials say. “On January 17, BOP will test micro-jamming and evaluate whether we can use that new technology in prisons without disrupting services in the surrounding area,” Rosenstein told a conference of state and federal correction officials in Orlando, Fla.

The Justice Department micro-jamming test is the agency’s latest effort to crackdown on phone use. In August, the Justice Department asked Federal Communications Commission regulators to come up with a way to stop inmates from using contraband cellphones, according to the Associated Press.