Recently the university entrance exam is over a period of time, must have many students know their own achievements, review the test the test time whether or not you will find that there is no signal around the examination room during the test, since the ancient times to cheat things exist all the time, especially in this era of science and technology progress cheating means but also emerge in endlessly, more and more clever, we see anti-cheating work more and more, of course, we have the common metal detector, the examiner examination, signal shielding and even fingerprint unlocked.
And signal shielding can be said to be the best method, especially in the progress of the electronic equipment, our time can even to escape detection, now means of cheating are almost all the people in the examination room with electronic equipment in speaking topic output to the outside world, and then the outside people to answer in order to achieve the purpose of cheating, and these need to be propagated through the network, the cell phone jammer is especially important.
Of course, we see the signal shielding actually is not popular, in some important examination such as the college entrance examination, the examination, civil servants will use, the effect of signal shielding effect is good, and the cost is low in fact can be popularized, metal detectors, after all, a lot of time and cannot be fully detected, so its signal immobilizer is how to do in this area within the scope of shielding signal, how it works?
Simple actually if we put these cheating electronic equipment as a two-way radios, the room of the outside receive, then the signal shielding device is a jammer to listen to your radio voice, our mobile phones for the electronic equipment it is need equipment to communicate with others through the base station, and the wireless communication is need to electromagnetic waves, according to the characteristics of electromagnetic wave, our equipment need to be in a certain frequency range can be accepted, so the signal shielding device is to interfere with your electronic devices that make the different frequencies, the frequency of so as to achieve the effect of shielding.
Some people think that I don’t have to I use bluetooth use wi-fi data network, these networks can actually now signal immobilizer shielding, already to add bluetooth and wi-fi band to scan range, because the network data and bluetooth wireless networks are actually different frequency range, these all within the scope of the scanning signal immobilizer, can do block it.