There are many different names for cell phone jammer, such as Phone Jammer, Cell Phone Jammer, Signal Jammer, Cell Phone Signal Jammer, Cell Phone Signal Blocker, Cell Phone Isolator, Interceptor cell phone, mobile communication signal jammer, cell phone signal Degree of protection device, cell phone jammer, signal jammer, cell phone blocker, signal blocker, cell phone signal isolator, signal isolator, interceptor cell phone signal, radio signal jammer, phone frequency jammer
For uplink and downlink channels of mobile phone system, it uses techniques such as frequency doubling, frequency division and frequency hopping filtering to analyze the required shielding frequency; customize a spherical shielding space according to the strength of the shielding device, and automatically form a shielding magnetic field within the specified range, so that mobile phones (including PHS-PHS-GSM-China Unicom, China Mobile, CDMA-China Telecom) in this space are invalid. When the jammer is in working condition, it can turn off the function of receiving and sending the signal of the mobile phone within the specified range, and can not call and call, so as to achieve the purpose of mandatory prohibition .
The principle of radio communication: in a certain frequency range, mobile phones and base stations are connected by radio waves, and the transmission of data and sound is supplemented by a certain baud rate and modulation method.
According to the communication principle of the telephone frequency jammer, the jammer scans from the low frequency of the channel going to the high end at a certain speed during operation. This scanning speed may cause scrambled interference in the message signal received by the mobile phone, and the mobile phone cannot detect the normal data sent from the base station, so the mobile phone cannot establish a connection. with the base station. The mobile phone manifests itself as a search network, no signal, no service system and other phenomena.
Features of cell phone signal shielding:
1. Protect only the downlink frequency of the transmitting base station without affecting the uplink frequency
2. Green and environmental protection, the intensity of electromagnetic field is much lower than the standard, and has no effect on the human body.
3. The operation is simple, the antenna is installed correctly, and it can work automatically when power is turned on.
4.It only protects the cellphone signal, and does not affect the normal operation of other electronic devices
5. Only protect cell phone signals and wireless cheat signals in the examination room, no interference with mobile phones outside the examination room, and no interference with the base station.
Transmission frequency range:
(1) 869 to 894 MHz
(2) 925 to 960 MHz
(3) 1780 to 1920 MHz
(4) 2010 at 2145 MHz
Shielded frequency bands: CDMA800, GSM900, SCDMA1800, DCS1800, PHS1900, TD-SCDMA (Mobile 3G), CDMA2000 (Telecom 3G), WCDMA (Unicom 3G)