Prisons are where criminals are located. There may be terrorists or criminal acts. Security is very important. Because contact with the outside world must be banned, the use of mobile phones and other electronic devices when contacting the outside world is not allowed to prevent security threats in the prison. Therefore, using a cell phone jammer in prison can prevent such things from happening. To avoid secret contact between prisoners and visitors, cell phone interference can help.
By sending the same radio frequency as a cell phone, the cell phone signal blocker works like a radio signal blocker. Doing so creates enough interference that calls cannot be connected to the phone. There are currently two types of phone blockers. The first category is usually smaller devices that block signals sent from cell towers to individual phones. The locking frequency is between 800MHz and 1900MHz. Most devices using this technology can block signals within a 30-foot radius. Cell phones in this range have no signal at all.
In timing applications, the mobile phone signal blocker may interrupt the GPS signal, causing the underlying system to lose its ability to synchronize its internal clock, and thus lose its ability to stay synchronized with the rest of the network. Because many critical infrastructure departments require synchronization of the entire network to within a millionth of a second, even short-term GPS outages can have a big impact. To make matters worse, when an outage occurs, there is usually no indication that it is due to traffic congestion. No longer receive GPS signals.