Can the shielding device be located in the examination room where the mobile phone has shielding device, and can it be detected that the short message is sent by that mobile phone?

The mobile phone signal blocker is just a blocker, and there is no detection function, so it is impossible to locate the mobile phone, let alone detect which mobile phone sent the short message. Only the 2G 3G 4G signals and 2.4G WIFI signals of China Mobile, China Unicom and China Telecom are blocked. Its principle is to interfere with the frequency sent by the base station and wireless router through its own frequency, so that the mobile phone can not communicate and surf the Internet.