The practical application of mobile phone jammer in real life
The college entrance examination is about to usher in one day. The college entrance examination is a key step in determining the destiny of children, so how to ensure the fairness of the college entrance examination is the goal of every examinee and parent's concern. In addition to strict proctoring measures, we will notice that there are some technology products that will be used in the college entrance examination proctoring, such as shielding instruments. Today, let’s talk about how cell phone jammer block signals?
——What is the function of a mobile phone jammer?
We know that when the mobile phone jammer is turned on in the examination room, the 2G, 3G, 4G signals of the mobile phone, wireless network signals, Bluetooth signals, etc. will be blocked. The mobile phone becomes a piece of scrap metal, unable to make calls, send text messages, or use mobile networks and wireless networks, and lose contact with the outside world. This cuts off the possibility of some opportunistic candidates using mobile phones to transmit answers and search questions, and ensure the fairness of the exam.
The current shielding devices on the market can limit cell phone signals within 500 meters from the launch pad and within a radius greater than 20 meters. Only shielding cell phone signals will not affect other electronic devices.
We know that after entering the elevator, we often cannot make a call. If the mobile phone has no signal, someone will tell us that the mobile phone signal is blocked. This is indeed a shielding effect. We learned in high school physics that when an object is covered by a "metal bird cage", external electrical signals cannot enter. The elevator is just such a cage.
According to reason, our examination room can also take the same measures to achieve a shielding effect. But this requires the classroom to be completely covered with metal, which is obviously impossible to do. Even if the classroom is really covered, although the two mobile phones in the same classroom have cut off the connection with the mobile base station, they can still connect via Bluetooth to transmit information.
Since this method of cutting off contact with the outside world cannot be used to shield the signal, what else can be done? One way people think of is to interfere with it. For example, at a football match with a lot of people, your friend calls you, I'm afraid you can't hear anything.
So, can we make the same noise signal transmitter to interfere with others' communication? The mobile phone jammer in the examination room is just such a device.
We know that mobile phone communication and network rely on the corresponding electromagnetic wave frequency band, just like a radio, when the frequency is matched, the communication is connected. The mobile phone jammer can continuously send electromagnetic waves from low frequency to high frequency, and interfere with the electromagnetic waves emitted by the mobile phone base station and wireless router, making it impossible for both parties to connect. The manifestation is the phenomenon of no signal and no network.