It's exam season now. When schools conduct large-scale exams, they must use the test room wifi jammer to prevent students from cheating by using mobile phones. Therefore, schools must install some exam room wifi signal jammers near the classroom before the exam, but when the school buys it. Which type of shield should I buy? If you are the person responsible for purchasing at your school, here are a few things to keep in mind:
1. Is there a base station near the school? In the process of construction, we often find that customers tell us that the wifi jammer device is ineffective. 2G and 3G can be shielded, which means that the call signal can be shielded, but the 4G signal cannot be shielded. In fact, the power of each wifi blocker is different, generally 4G1 and 4G2, the power is about 2W, that is to say, 33db. If there is a base station within 100 meters of the nearby, such a machine will also block the signal that is not 4G. It will also appear, customer feedback, has no effect.
2, How to distinguish the frequency. The frequency of the wifi jammer is 869~894MHz; 825~960MHz; 1805~1880MHz and 1900~1990MHz, etc. The working frequency bands are CDMA800, GSM900, DCS1800, and PCS1900. It can control a range of about 20 meters in diameter, using DC-DC converter input voltage, and 5V output voltage.
3. The mobile phone signal (234G) of the call can be selectively shielded. If you only shield 23G or only 34G, this can be adjusted before leaving the factory. In addition, there are 2.4GWIFI, 5.8GWIFI, VHF, UHF, and other frequency bands. How to understand it? That is to say, if you only want to block calls or WIFI, the manufacturer can focus on 2G3G on the host, and the cost will also come down.
4. Distinguish the power size. This is the easiest to fake, and it is also where manufacturers often play with cats. Because, to measure the actual power, a professional spectrum analyzer must be used. In the hands of ordinary customers, it is impossible to have such equipment. Therefore, it all depends on the professionalism of the customer's choice of equipment. Power size: wifi bluetooth jammer can generally be divided into low power, medium power, and high power, and the power is between 3W-100W.
The above are a few mistakes that should be avoided when buying a wifi blocker device.