Common signal blockers achieve mobile phone signal shielding by emitting interference signals. By emitting a high-power signal of a certain frequency, the surrounding electromagnetic environment is severely damaged, and the mobile phone cannot normally obtain and analyze the signal from the base station, thus achieving the purpose of blocking the mobile phone signal.
Under normal circumstances, when a mobile phone enters a certain cell for the first time, the local cell base station will update the location of the mobile phone and assign it a new temporary mobile user identifier and other temporary user information. After the mobile phone receives the base station information, So as to determine the location of your community. When the cell phone jammer is working, it emits an interference signal, which interferes with the effective signal on the base station broadcast channel frequency band. The interference signal increases the bit error rate of the mobile communication channel and reduces the signal-to-noise ratio of the channel, thereby affecting the mobile phone's Effective reception of base station broadcast information when the signal-to-noise ratio is reduced to a certain extent. The mobile phone cannot decode the broadcast information of the base station normally, and thus loses contact with the base station. The cell phone cannot determine its service area after repeated attempts, so the mobile phone in the interference area shows no signal and is not in the service area.
2. Signaling-level intelligent shielding technology
Signaling-level intelligent shielding technology is also called pseudo base station mode. The device scans the public network signal by scanning the antenna, then blocks the public network base station signal through signaling-level instructions, simulates the public network base station signal and transmits a fake base station signal into the environment to induce the mobile phone, thus blocking the mobile phone signal. When this kind of jammer operates, it can force the user's mobile phone signal to be connected to the device, making it impossible to connect to the public mobile communication network.