A gsm jammer is a device that transmits signals. Its frequency is the same as the frequency range used by mobile phones. It can effectively prevent its transmission by generating strong interference. In Europe, these frequencies are gsm 900MHZ and gsm 1900 MHz.
People who use mobile phones within the interference range will lose the signal, but they cannot know that the interference is the cause. The phone will only show poor reception.
Cell phone jammers come in various sizes, may affect the size of the radius, and may target multiple cell phone frequency bands (the frequency used to communicate with the tower). Interference can destroy the phone-to-tower frequency or the tower-to-phone frequency. The latter is usually more effective.
Choosing the right frequency depends on the equipment to be interfered with. In order to prevent mobile phones from receiving signals, mobile jammers should be used, which will block cellular frequencies. Therefore, the latest smart phones need to use GSM, 2G, 3G and 4G LTE. If you don't know the transmission frequency of your phone, all you have to do is to find its technical specifications on the Internet or elsewhere.
Of course, choosing the right GSM/CDMA network scrambler device also needs to consider the range of interference and portability. The interference device suitable for you will make you more comfortable to use. You can maximize the use of interfering devices without affecting other devices.