Why do we need portable jammers?

Internet smartphones are connected to mobile phone base stations (base stations) through radio waves and transmit voice, characters, and images to the other party through communication lines. It supports convenient life. Communication is possible within a radius of several kilometers. This is a kind of wifi interference, which emits radio waves, which is essential for wireless communication. However, many problems have also occurred. Someone was talking loudly in the car. Some people walk while typing cell phone emails. In this case, I want to block the radio waves of the phone. I want to stop the signal from working. The interfering device has arrived. I blocked the radio waves with a cell phone jammer on the train. In the blink of an eye, the radio waves disappeared and you can no longer use it. The problem is radio interference in public transportation. Therefore, the correct use of jammers is very important.