Due to the precedent that communication equipment was used to cheat in college entrance examinations in recent years, signal jammers have been widely used to completely eliminate these phenomena.
So what is the principle of the jammer used in the college entrance examination? In fact, this is the time it takes for your phone to send and receive messages. The cell phone jammer is like a loud-volume device. The "noise signal" output is too large, and the phone cannot hear the original sound. , Also known as wireless jammers. In short, the role of the shielding device is not to block the phone signal, but to disrupt or cover the phone signal. Corresponding to the use of electromagnetic signals, it is very useful when dealing with a large number of harmful signals.
Although phones are used whenever wireless communication devices are used, there are also invisible wires that act as base stations for cellular phones. The first step in making or answering a phone call is to connect to a nearby cell phone base station. If your left and right hands are mobile phones, and the left-handed person calls the right-handed person, the electromagnetic waves from the mobile phone will not be transmitted directly from the left hand to the right hand, but if it is simple, the distance from the mobile phone to the left roundabout is 100 metres.
Therefore, the signal in the examination room is disturbed. This seriously disturbed the mobile phone users in the examination room, and the quality of the call deteriorated. For the motherland flower, please support a few days.
But is this mask really effective? The entire frequency range of electromagnetic waves is from the smallest Hz to the largest hundreds of GHz, which is very wide. Any segment can be used as a communication signal, but some specific general protective equipment is "skilled enough" and "five types" of "incomplete sound" shielding can only block a few tools. You can use unshielded tape communication frequency tape communication.
Therefore, the number of jammers must be increased and continue to cover all areas
