Cell Phones With Call Blocking Installed
We all know that in some special scenarios, it is necessary to shield cell phone signals to prevent leaks or cheating. For example, in some confidential meetings, cell phones are not allowed to be carried, and if they arrive, cell phone signals will be blocked in the venue. . The most typical of these special scenes is the college entrance examination hall-the college entrance examination is almost one of the most important things in Chinese people’s lives. To ensure its fairness has become an important task of the local education bureaus. In order to ensure fairness, the college entrance examination venues will adopt various Various anti-cheating methods, such as metal detectors, examiner inspection, fingerprint unlocking, etc., and the most common one is Cell Phones With Call Blocking Installed . Nowadays, various electronic devices are emerging in an endless stream. Some of them can even evade detection after being disguised. Cheating candidates enter the exam room to output the questions to the outside world, and then people outside the exam room help to answer the questions in order to achieve the purpose of cheating, and the basis of all this That is-it must be spread through the Internet! cell phone jammer
In this case, Cell Phones With Call Blocking Installed is particularly important. How does signal shielding work? To put it simply, take a mobile phone as an example. The mobile phone needs to communicate with other devices outside the test room through a signal tower, and wireless communication needs electromagnetic waves to carry. According to the characteristics of electromagnetic waves, the devices on both sides Both need to be within a certain frequency range to send and receive, so the signal jammer is to affect the frequency of your electronic equipment to make the two frequencies different, so as to achieve the shielding effect. This principle is very simple, and the operation is also very convenient. So why did the examinee upload test questions to search for answers? Is it 5G? I think the problem lies in the fact that the staff in the examination room, especially the staff in charge of signal shielding, are too conservative! Generally speaking The mobile phone jammer in the examination room shields the mobile phone by interfering with the mobile phone jammer of the designated band. The frequency spectrum of the previous mainstream network 4G is generally between 1700MHz and 2600MHz. For example, China Mobile's 4G is mainly at 2320-2370 MHz, 2575- 2635 MHz two major frequency bands, while China Telecom is in the 1755-1785 MHz, 1850-1880 MHz two major frequency bands, and China Unicom is in the 1955-1980 MHz and 2145-2170 MHz. The examination room only needs to carry out electronic interference to the above frequency bands, and the 4G network of the mobile phone cannot be connected, so as to achieve the function of shielding the signal.