Have you heard of mobile phone jammers? To prevent cell phone communication, it is a cell phone signal interference device that prevents signal transmission between the mobile phone and the base station. This will cause strong interference to the communication between the caller and the receiver. Effectively prevent signal transmission including 3G, CDMA, GSM and PHS, unable to make or receive calls.
Mobile phones operate in different frequency bands in different countries. It tends to use the GSM 900 and 1800 bands in Asia and other regions, and the US uses the 850 and 1900 MHz bands. Using different frequencies makes it difficult to interfere with all frequencies. The right cell phone jammer is important, depending on the frequency you need to cut off. Even in theaters and commuter trains, cell phones are blocked.
Movie theaters and libraries use mobile phone signal jammer products, and I am reading books quietly. With the permission of the government, France can install interference equipment in public places such as theaters and concert halls. For many people, cell phones are a must. If your cell phone is annoying, cell phone jammers are very popular.