Free Cell Phone Robo Call Blocker Blocks Base Station Communication
The working principle of mobile communication is that within a certain frequency range, wireless devices (mobile phones, etc.) and base stations communicate through radio waves to complete data and sound transmission with a certain baud rate and modulation method. When the mobile phone communicates, it contacts the base station through the uplink frequency, and then transfers the signal to the mobile service switching center to realize the call. In the standby state, the mobile phone communicates with the base station through the broadcast control channel. Once there is a need for a call, the mobile phone will first be assigned to the mobile phone business channel according to the specific conditions of the channel near the terminal through the request, so that the mobile phone will jump to the business channel to realize the call and data transmission. . At the same time, wireless communication must ensure sufficient signal-to-noise ratio to effectively receive and complete the communication. According to the above working principle, Free Cell Phone Robo Call Blocker generally consists of power supply, electronic scanning control unit, segmented radio frequency module unit, amplifier unit, transmitting antenna unit and other parts. After the signal generator generates the scanning signal, it goes through the inverter, enters the oscillator and modulates it to the mobile communication working frequency band, and then is amplified by the power amplifier and the voltage regulator tube controls the power. The amplified frequency scanning signal is transmitted into the air in the form of radio waves.
Because the frequency sweep signal forms garbled interference in the message signal received by the mobile phone (increase the ratio of the noise signal to the device threshold), the mobile phone cannot receive the normal data sent by the base station, so that the mobile phone cannot establish a normal connection with the base station, so that the mobile phone is disconnected. Base station communication network. The mobile phone shows the phenomenon that the search network has no signal, no service system, etc., to achieve the blocking effect. The interference power of Free Cell Phone Robo Call Blocker is fixed, and the shielding radius of the unobstructed space is determined by the path attenuation and the signal level of the receiving base station. In order to achieve cell phone jammer interference to the mobile network, it must be ensured that the signal field strength of the mobile phone jammer is stronger than the field strength of the mobile signal in the interference area. The closer the interference location is to the base station, the stronger the field strength and the smaller the effective interference area. The farther the location is from the base station, the weaker the field strength and the larger the effective interference area. It can be seen that within a certain transmission power, the interference range depends on the field strength in the interference area. No matter how powerful the mobile phone signal jammer is, as long as the transmission power is constant, as the distance increases, the interference signal strength will gradually attenuate. thereby losing the ability to interfere. The mobile phone signal jammer output channel power, base station signal level, and coverage line gain can determine the theoretical coverage radius with reference value.