Telecom phones have shielding devices. Is there a signal?

Mobile phone signal shields are all 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 with the frequencies of mobile phones receiving base stations and wireless routers through their own frequencies, so as to achieve the purpose of shielding.

Therefore, after the shielding is turned on, the telecom mobile phone can't answer the phone, send text messages and surf the Internet normally. No service will be displayed, or there is a signal, but this is a virtual signal grid.

Unless there is a telecom handset signal amplifier nearby, the signal of the amplifier cannot be suppressed by shielded low power, and the telecom handset can be used normally.