Why signal jammer can interfere with your cell phone signal

Every year during the national college entrance examination, the school has some Internet problems, such as dropped phone calls and slow Internet access, because the school has turned on the cell phone jammer

The basic principle of a mobile phone jamming device is to emit the same radio frequency signal as a mobile phone. Because of the same frequency, the phone can’t tell which signal is a conventional base station signal, thus achieving “interference”. As long as there is a machine with the same frequency as the phone, it will make a lot of “noise” when the base station tries to connect to the phone. You will find that the signal from the cell phone is unrecognized, so you will refuse to communicate with the cell phone.

Many people don’t understand the difference between bluetooth, wi-fi and mobile data. It seems to be wireless communication technology, but the main difference between them is frequency band. In the mobile communication technology, 2G mainly works in the 900-1700mhz band, 3G works in the 1900-2100mhz band, and 4G works in the 2300-2500mhz band. Bluetooth and WiFi work in 2.4ghz.

At present, the main principle of signal shielding and signal jammer is to emit a huge noise in the frequency band used by mobile phones, interfering with the reception and transmission of normal signals. The gadget is often used not only to prevent cheating on exams, but also to prevent terrorist attacks politically and militarily. But the signal jammer is not like shopping for vegetables, not just to buy and use, or it may be illegal.