The classroom is usually not very large, so it is recommended to use a mobile cell phone jammer. This is very convenient to carry and use. You only need to press a button to open it. Of course, you don’t have to worry about emergency situations where someone needs to call you. They can leave the classroom and call without disturbing others. Or, you can turn off the interference device as needed. Some devices can interfere with telephone signals. In essence, it pretends to be a base station, not a base station. The problem is that it disables emergency calls. In theory, when the phone is in an unauthorized location, you can achieve the function of switching the phone to “silent mode” (because the operator always knows the location of the phone). However, no one proposed it as a product or standard, but it is not particularly difficult. You may have to pay for this because you are the owner of a movie theater or a restaurant.
Most jammers are designed for military use, for example, to confuse the exact location of the enemy, or where the enemy’s GPS guided missiles or bombs land. However, there are several civilian applications that can interfere with GPS signals. For example, it can hide you and your car while being tracked by a GPS receiver. Recently, fraud cases occurred in the entrance examinations of four famous universities including Kyoto University, and mobile phone jammers have become the focus of attention. The school there recently tested a 5g cell phone jammer to allow their children to focus on their studies, but admitted that this might be illegal. They have confirmed with FCC. “We just want to evaluate it,” said principal John Hook.