Is it possible to block cell phone signals throughout the school?

As you can see from what you have written, this problem is particularly serious in your case. You need to cover the entire school with blocking signals that block 3G, 4G, and all GSM and CDMA frequencies. The equipment you choose to use is correct. The only threat to WiFi networks is 4G cell phone jammer because its frequency is indeed close to the WiFi frequency. I can suggest that you bring an XLG15 and test whether it will interfere with your school’s WiFi network. If so, then there will be two options: leave the 4G band to students and faculty or accept the fact that your smart board and security camera are performing worse than they should.

As you know, the problem of students using mobile phones and other personal items at school is not new, but different schools deal with it in different ways. You have decided to ban the use of mobile devices for the entire school, maybe this is right. In any case, I hope my answer can help you successfully deal with this matter!