Although the Dual Band Cell Phone Jammer standard configuration can shield all the 2G 3G 4G signals, 2.4G WIFI signals and Bluetooth signals under all the three operators of China Mobile, China Unicom and China Telecom, it does not mean that any mobile phone jammer can perform well. Shielding effect. Because it not only has a lot to do with the area of the place of use, but the most important point is whether there is a cell phone signal amplifier near the place of use. cell phone jammer When working, it will send out the frequency to interfere with the downlink signal of its base station. If the Power of the mobile phone jammer is greater than the Power of the local base station signal, then the mobile phone will have no signal. If the Power of the mobile phone signal jammer is less than the Power of the local base station signal, the mobile phone There will be a signal. Therefore, in your school examination room, the greatest possibility is that there is a signal base station near the school, and the Power of the mobile phone jammer is not suppressed.
Under normal circumstances, after the test center Dual Band Cell Phone Jammer is turned on, all mobile phones have no signal. If the mobile phone can still receive the signal, it may be that the mobile phone jammer has not been turned on, or the location is in a blind spot, and the mobile phone signal jammer is not covered. The mobile phone jammer scans from the low-end frequency of the forward channel to the high-end at a certain speed during operation. This scanning speed can cause garbled 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 that the mobile phone cannot establish a connection with the base station. The mobile phone is manifested as a search network, no signal, no service system and other phenomena.