Some colleges and universities use signal jammers to prevent students from cheating in examinations, which is one of the main reasons why the invigilation mode of schools has gradually changed from manual to computer-based examinations. On the other hand, the installation of signal jammers also reduces the burden of invigilating teachers and reduces the waste of human resources to a certain extent. In class, some students secretly use their mobile phones to read novels, make phone calls, send messages and so on, which can be controlled by shielding equipment. At present, more and more schools choose to install signal jammers, which also plays a very important role in schools.

As a very simple electronic device, mobile phones can easily get the answers from the Internet of things. This small and easy to hide communication instrument gives invigilators a headache. However, it is still easy to use the signal jammer to disturb the mobile phone signal. Once the device is turned on, the mobile phone can not receive any signal, and students can not cheat online through their mobile phones. According to the distance between the site base stations, measure the field signal strength. In addition to the size of the examination room or classroom space, it is quite appropriate to install such equipment to cover the signals used by mobile phones, so as to destroy the connection between mobile phones and base stations. Select the signal jammer with a power greater than the normal signal strength to achieve the desired shielding effect.