Popular Science: How does a cell phone signal blocker block cell phone signals?
The college entrance examination is one of the most important exams in the country every year. In fact, it is not only the college entrance examination, no matter what kind of exam it is, fairness is the most important thing for each candidate. Therefore, preventing candidates from cheating in the examination room is the job of the examination staff. The top priority within. There are various ways of cheating. The most common one is to use various communication tools to cheat in the exam. In order to prevent this phenomenon, the mobile phone signal shielding device plays a crucial role in the examination room.
It is believed that in the two days of the college entrance examination, many small partners will receive text messages from the operators. The text messages indicate that the mobile phone signal blocker will be turned on according to the requirements of the Education Bureau during the test period, which will affect the communication quality of mobile phone users around the school until the end of the test. After that, the communication will return to normal. Therefore, the mobile phone signal blocking device is turned on in the examination room, and the mobile phone cannot communicate.
How does a cell phone signal blocker block cell phone signals? It turns out that the mobile phone signal shielding device scans from the low frequency band of the forward channel to the high frequency at a certain rate during the working process, and transmits white noise interference signals to interfere with the signal of the mobile phone receiving the message, so that the mobile phone cannot detect the base station normally. The data connection sent out, so that the connection with the base station cannot be established, the mobile phone shows no signal, and the service is limited.
At present, the mobile phone signal jammers used in the examination room are all frequency bands, including 2G-5G of three operators, and include the radio and television 5G frequency, as well as the WiFi signal Bluetooth signal, and some cell phone jammer also include VHF/UHF, etc. The interference of the walkie-talkie signal makes mobile phones and other cheating devices such as walkie-talkies unable to receive wireless signals normally. To a certain extent, it can effectively prevent candidates from cheating by using various cheating devices, and maintain the fairness of the exam.