During the college entrance examination every year, the school will have network problems such as mobile phones network dropped and slow Internet access. That is because the school has opened a cell phone signal jammers. If we think of the phone as a handheld two-way radio, the radio can be disturbed, then the phone is no exception. Like the radio, the signal from the phone is also disturbed.
Jamming mobile phone signal is just like interfering with other types of radio communication: the mobile phone communicates with its service network through the base station, and constantly switches the base station connected to itself during the daily movement. We know that wireless communication uses electromagnetic waves for communication. The functional characteristics of electromagnetic waves are determined by their frequency. Our mobile phones must emit electromagnetic waves that meet the requirements in order to connect to our communication carrier base station.
Different communication systems use different frequencies, so that everyone is safe and does not interfere with each other. The basic principle of a cell phone jamming device is to transmit the same RF signal as the mobile phone. Since the frequency is the same, the mobile phone cannot distinguish which signal is a conventional base station signal, thereby achieving "interference". In the early days, the jammer only blocked a set of frequencies, such as 2G, but now complex jammers could block several types of networks at the same time, such as 3G 4G WIFI GPS,etc.
Bluetooth, Wi-Fi and mobile data are not understood by many people. They seem to be wireless communication technologies. In fact, the main difference between them is the frequency band. In mobile communication technology, 2G mainly works in the 900-1700MHz frequency band, 3G works in the 1900-2100MHz frequency band, and 4G works in the 2300-2500MHz frequency band. Bluetooth and WiFi work at 2.4GHZ. Therefore, different mobile portable cell phone jammers interfere with different frequencies.
At present, the main principle of the signal jammer is to emit huge noise in the frequency band used by the mobile phone, which interferes with the reception and transmission of the normal signal of the mobile phone. This small object is not only often used to prevent cheating in exams, but also used politically and militarily to prevent terrorist attacks. But the signal blocker is not like shopping for food, it is not casually purchased and used, otherwise it may involve illegality.