In the past, shielding equipment was indeed used in examination rooms. The method of shielding mobile phone signals was to emit signals similar to those of base stations, which would overwhelm the base station signals within a short distance; mobile phones would not be able to find the base station signals.
However, because the signal intensity emitted by the shield is relatively large, it has an impact on the human brain. Later it was no longer allowed to be used.
Even without the signal blocking function of mobile phones, other safer and more environmentally friendly detection methods may be used. Therefore, it is safer not to make any plans in this regard.
To crack the cell phone signal jammer and get the cell phone signal, you must first understand its principle:
Mobile phone signal jammers are divided into omnidirectional and directional types according to the shape of the shield. The omnidirectional type is an olive shape, and the directional type is a fan shape, so the omnidirectional jammer is better than the directional jammer. The shielding area is large;
The mobile phone signal jammer generates a certain electromagnetic wave to interfere with the downlink of the mobile signal. If the power of the signal blocker is greater than the power of the local mobile signal, then the mobile phone will have no signal. If the power of the jammer is less than the power of the local mobile signal, the mobile phone will have no signal. There will be a signal.
So the way to crack the jammer is to install a mobile phone signal amplifier.
one. It has a certain scope of use
Although the mobile phone signal jammer is called a jammer, it does not actually block the signal. Instead, it acts like a signal jammer. Generally speaking, the connection between mobile phones will pass through the base station, that is, the path of mobile phone-base station-mobile phone. The signal jammer will interfere with the communication path between the mobile phone and the base station, resulting in abnormal transmission. However, the base station is shared by mobile phones within a certain range, so there are often situations where mobile phone signals cannot be used normally even when not in the examination room.
2. It is not omnipotent
Mobile phone signal jammers currently on the market can limit mobile phone signals that are 500M meters away from the transmitting station and have a radius of >20 meters. The shielding radius is adjustable, it only blocks mobile phone signals and does not affect other electronic devices.
So if your mobile phone signal is not good recently when you are not near the examination room, don’t blame the signal jammer. It may also be a problem with your own mobile phone.
3. Interference frequency bands are regulated
The entire frequency band of electromagnetic waves is very wide, from a minimum of a few Hz to a maximum of tens of hundreds of GHz. Each segment can be used. Generally speaking, the following are commonly used:
The GSM receiving frequency band is 885~960MHz;
The receiving frequency band of CDMA is 869-894MHz;
The receiving frequency band of DCS is 1805-1880MHz.