Most Jammers are built for military uses, for instance, to confuse the enemy on where their exact location is or where the enemies GPS guided missiles or bombs will fall. However, there are a few civilian uses for jamming GPS signals including the ability to conceal oneself or one’s vehicle in the case that it is being tracked by a GPS receiver.
Cell phone jammers have come under the spotlight in the wake of recent cheating incidents during entrance exams at four prominent universities, including Kyoto University.A school there recently tested a 5g jammer to get kids focused on academics, but admitted the move may not be legal. They’re checking with the FCC. “We just thought it was something we wanted to evaluate,” said Principal John Hook.
Such jammers transmit radio signals in the 800 MHz frequency band, which is used as the mainstream carrier frequency band for NTT DoCoMo’s and KDDI’s au phones. Products targeting other frequency bands are also available.At present, the main corporate users of the jammers are the operators of hospitals, concert halls and cinemas, while some banks have also installed the device at their automated teller machines to help prevent “ore-ore” (it’s me, it’s me) frauds.
“GPS is so embedded in the transportation, manufacturing industries and economies of our societies that the risk is high,” said David Last, an Emeritus Professor of Bangor University in the U.K. and a well-known authority on criminal use of GPS jammers.
Presently, the mobile jammer devices are becoming civilian products rather than electronic warfare devices, since with the increasing number of the mobile phone users the need to disable mobile phones in specific places where the ringing of cell phone would be disruptive has increased. These places include worship places, university lecture rooms, libraries, concert halls, meeting rooms, and other places where silence is appreciated.