|0 follower Shoko Ishida E-nautChina|
Cell phone jammer is device used to prevent cellular phones from receiving signal from base station. They can be used anywhere but mostly used where phone call would be disruptive. Cell phones are very useful because we are able to contact anyone at anytime but sometimes it become nuisance. Some cell phone users don't know when to stop talking. Jammers are used at classrooms, temples, churches where silence is required. It creates a temporary "dead zone" to all cell phone traffic in their air system.
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.
Cell phones are full-duplex devices, which mean they use two separate frequencies, one for talking and one for listening simultaneously. Some jammers block only one of the frequencies used by cell phones, which has the effect of blocking both. The phone is tricked into thinking there is no service because it can receive only one of the frequencies.
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.
According to the state minister for national security Pearnel Charles Jr, the government is advancing the process of identifying and selecting the best, and most modern cellular wifi jammer and other technology solutions. Meanwhile, he says the restoration of the jammers at Tower Street highlights the lack of maintenance and underutilisation in recent years.
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.