The mobile phone jammer only shields the mobile phone signal in the examination room
Although the time for the college entrance examination this year was affected by the epidemic and was postponed to July 7-8, in order to ensure the information security of the examination room, the corresponding measures have not been reduced at all. Operators have issued announcements that during the exam period, the mobile cell phone jammer will be turned on in accordance with the requirements of the Education Bureau, which will affect the communication quality of mobile phone users around the school. The communication will not return to normal until the end of the exam. What is the role of mobile phone jammers during the college entrance examination? The invigilator at the entrance of the examination room is waving a metal detector. Does it really work?
To know what is the effect of shielding mobile phone signals, let's first understand the working principle of mobile communication. As a mobile communication device, a mobile phone needs to establish a connection with a nearby base station when communicating, and then access the core network to find the communication destination. In the above process, all information is carried and transmitted through electromagnetic waves. The electromagnetic wave frequency band used by the mobile phone is related to the system used by the mobile phone and the operator where it is located. But in general, the electromagnetic wave frequency bands used by the three operators are distributed in the range of 850-4900MHz. If the college entrance examination organizer wants to shield the mobile phone signal in the examination room, it is impossible to make the 2G/3G/4G/5G base stations near the examination room not work, otherwise all the communication equipment in this area will not be able to communicate normally. Then the only way to use cell phone jammers to shield cell phone signals in the examination room.
When it comes to shielding mobile phone signals, the first thing that comes to mind is metal shielding, that is, the mobile phone is placed in a closed metal box to block the propagation of electromagnetic waves through metal. However, it is obviously impractical to make all classrooms in the examination room into metal-enclosed classrooms. then what should we do? It's very simple, only a small cell phone signal jammer is needed to block all cell phone signals in the examination room.