There is no way to stop it. The shielding device is a so-called mobile phone jammer, which can shield all communication signals and cannot be stopped. The mobile cell phone jammer currently on the market can limit the signal of mobile phones that are 200 meters away from the transmitter and have a radius of more than 20 meters. The shielding radius is adjustable, which only shields mobile phone signals and does not affect other electronic devices. Save electric energy, power 20W. When the mobile phone is working, it is within a certain frequency range. The mobile phone and the base station are connected by radio waves, and the data and sound transmission is completed with a certain baud rate and modulation method.
For this communication principle, the scanning speed will cause garbled interference in the SMS signal received by the mobile phone, and the mobile phone cannot detect the normal data sent by the base station, resulting in the mobile phone being unable to establish a connection with the base station. The mobile phone is manifested as a search network, no signal, no service system and other phenomena. Common mobile phone signal jammers on the market have operating frequencies: 869~894MHz; 825~960MHz; 1805~1880MHz, 1900~1990MHz, etc. The working frequency bands are CDMA800, GSM900, DCS1800, PCS1900. It can control a range of about 40 meters in diameter, using a DC-DC converter input voltage and 5V output voltage.