Pornography Block For Cell Phone Blocks Malicious Surveillance
In previous years' college entrance examination, careful candidates will find a car with a big disc parked outside the examination room, which is particularly eye-catching. This car is not here to "play soy sauce", but a radio monitoring car. This large disk is called a directional antenna, which is the "eye of the sky" of the monitoring vehicle. There are nine receiving antennas in the disk. Except for the ruler antenna pointing to the north, the other eight antennas point to eight different directions respectively, which can monitor the All radio signals within a 1.3 km radius. In addition to a laptop computer, there are four Pornography Block For Cell Phone instruments in the monitoring vehicle. "Two of these four instruments are receivers, and the other two are radio suppression equipment and directional systems. Two of the receivers are equivalent to the 'heart' of the monitoring vehicle, which can realize dual-channel work and monitor while monitoring. Orientation of key signal sources." According to reports, the education department has installed Cell Phone Jammer in the test center, and the mobile phone signal is blocked, so there is no chance to cheat through the mobile phone, and the main purpose is to prevent cheating through radio equipment. Through instrument monitoring, once the electromagnetic environment and the previous spectrum are abnormal after the test, technicians can find and track suspicious signals at the first time.
At present, the radio signals used for cheating in exams mainly include voice analog signals and digital signals. Once suspicious signals are found, the suspicious signals should be monitored and demodulated. If it is finally confirmed to be cheating signals after analysis, recording and evidence collection should be performed first to complete the evidence fixation. Immediately after the suppression, high-power radio suppression equipment is used to suppress the information, so that candidates who intend to receive cheating information in the examination room will not be able to answer the information, but can only hear the popular songs played by the technicians. According to reports, while suppressing, relying on the mobile monitoring and direction-finding system in the monitoring vehicle, the emission source of suspicious signals around the test site can be quickly found. According to past experience, Pornography Block For Cell Phone is generally not too far from the test center. They like to hide in hotels, parks and other places around the test center, and some of them hide in cars outside the test center. It should be noted that due to the point-to-point suppression, the radio monitoring vehicle will not interfere with the radio communication in the examination room, including the playback of English listening, nor will it affect the normal communication of mobile phone users around the examination room.