Every examination season, all ordinary colleges and universities and education departments in various districts should strengthen positive publicity and do a good job in policy interpretation, voluntary filling in, information inquiry, warm tips and other service work. Strengthen integrity education for examinees, focus on publicizing laws and regulations related to the examination, educate and guide examinees to consciously resist violations of discipline, fraud and other behaviors.
Cheating has occurred in all examinations in the past. With the development of science and technology, more and more people use mobile phones to cheat. It has become an issue that education departments pay more and more attention to. Some ordinary colleges and universities in order to ensure the safety of information in the examination room, generally use signal jammers to interfere with external signals in a certain range. Today, we will talk about how the school mobile phone signal jammer interferes with mobile phone signals.
1. How do jammers interfere with cell phone signals?
In order to understand how the jammer interferes with mobile phone signals, we must first know the working principle of mobile communication, simply say that it is in a certain frequency range, the mobile phone and the base station through the radio wave contact, with a certain baud rate and modulation mode to complete the transmission of data and sound.
When the mobile phone communicates, it contacts the base station through the uplink frequency, and then transfers the signal to the MSC (Mobile service switching Center) to realize the call. In the standby state, the phone contacts the base station through the BCH broadcast control channel. Once there is a call demand, the phone first asks the MSC through BCH, and the MSC allocates the phone service channel according to the status of the channel, so that the phone can jump from BCH to the service channel to realize the call.
2. What is a jammer?
Let's take a look at what is jammer, jammer is also known as mobile phone signal blocker, mobile phone signal blocker, security device, etc. Their working principle is to implement the same frequency electromagnetic interference to the wireless network on which the mobile phone communication depends, so that the mobile network can not communicate normally, so as to achieve the purpose of interference. Mobile phone signal blockers only block mobile phone signals and have no effect on other electronic devices.
It should be noted that in order to realize the jamming of the jammer on the mobile network, it must be ensured that the signal field strength sent by the jammer is much greater than the field strength of the mobile signal BCH in the jamming area. The closer the jamming site is to the base station, the stronger the BCH field strength is and the smaller the effective interference area is.
It is necessary to strengthen the discipline of the examination room and prohibit any cheating. In addition, mobile phone signal blockers are also applicable to the military, government agencies, prisons, gas stations and other places that prohibit the use of mobile communications.
