As far as we know, cell phone signal shielding device is mainly aimed at all kinds of examination room, school, gas stations, the church, the court, library, meeting center (room), theaters, hospitals, government, finance, prisons, public security, military area and other places to ban the use of mobile phone. In such an occasion the signal is not sent in.
When the phone works, it is within a certain frequency range. The cell phone and the base station are connected by radio waves, and the data and sound transmission can be completed by certain baud rate and modulation mode. For this kind of communication principle, the mobile phone signal shield is at a certain speed in the working process to the high end of the channel to the high-end scanning. The scanning speed can be used to generate random interference in the receiver's signal. The phone can't detect the normal data from the base station, and the cell phone cannot be connected to the base station. Mobile phone performance is search network, no signal, no service system and other phenomena.
The common cell phone signal shield in the market, its function frequency is: 869~894MHz; 825 ~ 960 MHZ; 1805~1880MHz and 1900~1990MHz etc. The frequency band is CDMA800, GSM900, DCS1800, PCS1900. Can control the range of 40 meters in diameter, using DC-DC converter input voltage, 5V output voltage.
The benefits of installing gps jammer in schools
In the information age, mobile phones seem to have become a necessity for life, and nowadays it is not uncommon for students to bring mobile phones to school. Although small and medium-sized schools around the world are not allowed to carry mobile phones while they are in school, the phenomenon has repeatedly been banned. In recent days, a high school in the provincial capital has been forced to turn off the lights in the evening and turn on the "high-tech" -- mobile phone screening device. I didn't think that the kind act attracted some parents' complaints. One was that they were afraid that the screening instrument was not good for the students' health, and the other was that they would lose contact in the middle of the night. The school was forced to stop using mobile phone shielding.
As long as it is electronic products have radiation, as for the radiation shielding device, slightly larger than the cell phone, routers, but choose normal manufacturer's products, through the national multiple departments detection, conforms to the national radiation protection sign value, there is no impact on the human body. The radiation is less than 40 microwatts per square centimeter and is safe.
Why do you need to install a phone gsm jammer? Some students will send messages to each other on their mobile phones during the exam, or even check their compositions on the Internet, and install the shield to prevent students from cheating on their mobile phones. Many students will lie in bed after class or late study. There is a lot of bad information on the Internet, which is bad for students' growth and study. Some students send text messages and phone dates before they go to bed late in the evening, affecting the next day.
Most of the parents to the school of understanding, they think that most mobile phone games and Internet access, if students indulge in games and surfing the Internet, not only affect rest, can't concentrate on studies. It is necessary for schools to block mobile phone information to protect students.