Knowledge: the signal is actually encrypted transmission of electromagnetic waves, the signal peaks and troughs on behalf of 1,0. cell phone jammer play a superposition of waves, resulting in the shielding effect.
We do not know being followed in many cases, in order to prevent such incidents, GPS blocker have used as a guard against such incidents occur.
Some shielded tool does not really shielded signal, and mobile phone jammer to be true, it produces interference by superimposing the signal waveform, thus significantly weakening the signal to disappear.
mobile phone jammer used in schools should be legalized because it can contribute to student learning and exam fairness.
Knowledge: mobile phone jammer in some countries is within the exclusive tool, most people can not be used, is that legal constraints and security constraints. Only some institutions have the right to use.