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.
In South America, we always use Signal Jammers as our tools necessary.
Teachers in the school have the right to use Signal Jammer, so we can not use the phone when the class, this is too make people mad.
GPS jammer can be installed in a vehicle. It allows GPS useless in some confidential within the company needs is a very important significance.
How to make a cell phone jammer? In China to buy a small module, so you have a test board, and can be assembled according to their needs a 4g jammer.