Cheating has always existed since ancient times, especially in our era of scientific and technological progress. Cheating methods are emerging in endlessly and becoming more and more sophisticated. Of course, we see more and more anti cheating work. We often see metal detectors, examiner checks, signal shielding and even fingerprint unlocking.
In fact, in the opinion of Texin editor, signal shielding can be said to be the most brilliant means, especially in our era, the continuous progress of electronic devices can even avoid detection. Now, almost all cheating means are that people in the examination room carry electronic devices to speak questions and output them to the outside world, and then people outside the examination room answer questions to achieve the purpose of cheating, which needs to be spread through the network, At this time, signal shielding is particularly important.
Of course, we can see that signal shielding is not yet popular. It is only used in some important examinations, such as the college entrance examination, the national examination, and civil servants. Xiaobian believes that the signal shielding device has a good effect and low cost, and it can be popularized. After all, metal detectors can not be completely detected many times, so how does the signal shielding device shield signals in this area, What is its working principle?
In fact, to put it simply, if we treat these cheating electronic devices as a two-way radio, the broadcast in the examination room and the reception outside the examination room, then the signal shield is an influence device to make your radio sound inaudible. Our mobile phones, these electronic devices, need to communicate with other devices through the signal tower, while wireless communication needs electromagnetic waves. According to the characteristics of electromagnetic waves, Our equipment needs to be received within a certain frequency range, so the signal shield is to affect the frequency of your electronic equipment to make the frequencies of both sides different, so as to achieve the shielding effect.
Some people think that I don't use data networks, I use Bluetooth and Wi Fi. In fact, today's signal shielding devices can shield these networks. The frequency bands of Bluetooth and Wi Fi have long been added to the scanning range, because in fact, the network data and Bluetooth wireless networks have different frequency ranges, and these can be shielded if they are included in the scanning range of the signal shielding device.
The original design of signal shielding device is to fight crime and serve law enforcement departments and the military, so in fact, buying signal shielding by oneself will also be suspected of violating the law. After all, the powerful function of signal shielding device may become a bad influence in the hands of criminals. In fact, we can simply see that the principle of signal shielding is very simple and easy to understand, and the shielding effect can be achieved by affecting different frequency bands.