> Calls can still be made > Teacher's phones seem to be completely unaffected Then they're not using a jammer. There are other things they could be doing, tho

> Calls can still be made > Teacher's phones seem to be completely unaffected Then they're not using a jammer. There are other things they could be doing, though, that have the advantage of not being illegal. My guess is that other commenters here are correct: they have their own cell "tower" in the school and they're filtering things through that.