Can the mobile phone receive the message after the signal is blocked?

At present, mobile phone signal shielding is full-band, which can shield all 2G 3G 4G signals, 2.4G WIFI signals and Bluetooth signals of China Mobile, China Unicom and China Telecom. Its principle is to interfere the mobile phone to receive the frequency sent by the base station and wireless router through its own frequency, so as to achieve the purpose of shielding.

Therefore, as long as the screen is on, the mobile phone in the examination room can't answer the phone, send text messages or surf the Internet.

Unless there is a cell phone signal amplifier near the school, some cell phones can be used normally.