# How to calculate the shielding range of the full-band shielding instrument

Many customers called and said that I need a full-band shielding device that can shield a radius of 50 meters, a distance of 500 meters, and a radius of one kilometer, and it needs to shield all three networks of China Mobile, China Unicom and China Telecom. Is there a problem with the customer's request? No problem, and specific distance requirements are also given, but can it be completed? The answer is more difficult to achieve. Why is it more difficult to achieve? Doesn’t the parameter of the full-band shielding instrument have its own shielding interval marked, can’t it be completed by placing a few more sets according to this distance? In fact, the customer is not wrong, but they do not know that the shielding plan of the full-band shielding instrument is not a fixed value, how to understand it?

The full-band shielding device scans from the low-end frequency of the channel to the high-end at a certain speed during the working process. This scanning speed can form garbled interference in the message signal received by the mobile phone, causing the mobile phone to fail to detect the normal microwave signal data sent from the base station. , Within a certain range, the mobile phone cannot establish a connection with the base station, so as to achieve the purpose of shielding the mobile phone signal.

To put it simply, the frequency emitted by the full-band jammer interferes with the frequency of the mobile phone to receive the base station. The jammer and the base station are bound to be a competition. If the channel power is lower than the channel power, the jammer cannot shield it. Only when the power of the full-band signal jammer is greater than the power delivered by the base station to the mobile phone can effective shielding be achieved. Therefore, any jammer used in different signal environments will show different shielding distances, and China Mobile, China Unicom and China Telecom will be different, because the base station density, base station location and base station power built by these three operators cannot be the same of.

That is to say, how many meters the full-band shielding device can shield is not only related to its own transmission power, but also related to the distance of the base station in the use environment (base stations are not limited to large-scale transmission towers built on the ground, but also on the roof of buildings. Another important factor for the signal amplification antenna on the Internet and the signal amplifiers made in some buildings is obstacles, which will be directly blocked if they are made of metal; if they are solid walls of reinforced concrete, they will be attenuated by at least 10 times after penetration; If it is wood or glass material, the attenuation after penetration is relatively small.

So the next time a customer asks how many meters the shielding distance needs to be, he must ask how far the base station is in the environment, whether it is for indoor or outdoor use, whether it needs to go through walls, and so on. Only by understanding these can we better choose a suitable full-band shielding instrument for customers.