The ability to successfully block a cell phone signal is basically the same as blocking any other type of cellular communication with a standard signal blocker. As cellphone users drive down the street, the signal is passed from tower to tower like a football. Cell phone jammers can successfully transmit over the opposite radio frequencies used by these wireless devices. This “white noise” effectively interrupts the communication between the base station in the tower and the mobile phone. This is technically called “no service”. Cell Phone Jammer Kits have been specially developed to cancel signals in the radio spectrum of cell phones within range of jamming devices.
Most sirens are wireless these days, and some tool thieves have replaced their tools with GSM jammers. GSM jammers or “jammers” are indeed the villain’s new weapon, which can kill the communication of GSM alerts. GSM jammers can fit in your pocket and cost less than 50 euros for entry-level products. This kind of tool only equips certain organized criminals and makes up only a small percentage of thieves, but as long as the technique proves somewhat ineffective, it should continue to grow. At best, the device is regulated, let alone banned on French soil, but of course you can easily get “banned” models on the internet with just a few clicks.