Cell phone jammer is a device used to prevent mobile phones from receiving signals from base stations. They can be used anywhere, but are usually used where calls are interrupted. Mobile phones are very useful because we can contact anyone at any time, but sometimes it becomes very troublesome. Some mobile phone users do not know when to stop talking. Jammers are used in places where quietness is required. It creates a temporary "dead zone" for all mobile phone traffic in the air system.