The jammer behaves like a small, independent and portable base station, which can directly interact intelligently or non-intelligently with the operation of the local mobile phone. Most of the jammers are in receiving mode. When the mobile phone is close to the jammer, it will intelligently choose to directly interact and block the mobile phone. This selective jamming technology uses a discriminator to target the jammer. The advantage of this target selectivity is that compared to the original power transmitted by the jammer and the spectrum, there is much less electromagnetic pollution, and therefore much less interference to traffic. The traffic jam signal will only continue. How does the phone continue to connect to the base station. Otherwise, interference will not occur. This technology forces the connection to be interrupted or cancelled, and then returns to passive reception mode. This technology can be implemented without the cooperation of the PCS/mobile radio provider, but it may have a negative impact on the operation of the PCS/mobile radio system. Compared with Type B, this technology has an additional advantage, that is, negotiating with the cellular network does not require extra effort or expense. In addition to Type B, the device can also distinguish 911 calls and achieve breakthroughs in emergency situations.
Mobile cell phone jammer are hard to find. Researchers say that only changes to the GSM standard can prevent such attacks. These will be difficult to implement. They complain that the industry refuses to add new standards to existing networks. As more authentication and traffic can resolve this vulnerability, it will also be expensive. Since attacks not only target network operators and organizations, but also individual users, they may cause further financial losses when security breaches occur. The computers used in their research are the same as those in Berlin before, and as long as 11 mobile phones can weaken the Berlin network. The scientist said: “You can respond to all paging requests and block the moving area.” This affects the entire community. However, more calls need to be made during peak hours to meet the demands of more disruptive providers. Attackers can cover an area of 200 square kilometers on average in Berlin.