Have you heard of cell phone jammer? The mobile phone is blocked from communication. It is an out-of-service device that blocks the transmission of signals between mobile phones and base stations. It causes strong interference with the communication between the sender and the receiver. Effectively blocks the transmission of signals including 3G, CDMA, GSM and PHS. I can't make or receive calls. It may cause more problems than improper use. Everyone in these industries is convinced.
Mobile phones operate in different frequency bands in different countries. It tends to use the GSM 900 and 1800 bandwidth in places such as Asia. The United States uses the 850 and 1900 MHz bands. The use of different frequencies makes it difficult to have interference for all frequencies. Depending on the frequency you need to block, a suitable smartphone jammer is important. Mobile phones are blocked from theaters to commuter trains. Movie theaters and libraries use these products. I'm quietly reading a book.
Japan can install jamming radio waves in public places such as theaters and concert halls if it obtains a government license. This device violates personal freedom. We have determined that it may affect public safety. He sells jammers and says he is expanding his business around the world. Sometimes I forget to turn off my cell phone. For many, mobile phones are a necessity. Wifi jamming is very popular when your cell phone is annoying.