How Jammers Work And Why Their Use Is Prohibited

Have you ever gone to open your car with the remote control and it did not open? Ok, you may have run out of batteries, but it could also happen to you because you were near a police station, barracks, or other specially protected places. Perhaps at that moment, you did not realize why this could happen to you, but the answer is very simple: frequency inhibitor.

How Jammers Work And Why Their Use Is Prohibited

Jammers are devices that range from the size of a hip flask to that of a suitcase with a very simple purpose: interrupt communications. And today getting one of these devices is not too complicated, but another thing is the legality of its use. Let’s get to know in depth how they work and why they are prohibited from using them.

What is an inhibitor and how does it work?

Frequency inhibitors have a very clear and simple objective: to prevent communications on certain frequencies. But since it is not easy to block a device so that it cannot communicate with another, the solution to prevent this transit of information is very simple and similar to a DDoS attack: introduce noise on the indicated frequency, useless information that saturates the band, preventing that the true information does not arrive.

Jammers can be used to interfere with different types of communications or devices, from mobile networks, speed cameras, Bluetooth, GPS, infrared… But despite their variety of uses, all jammers are simple. They are based on a circuit that has an oscillator that generates the signal, a noise generator, a gain stage to give the signal enough power, and finally one or more antennas that transmit what is generated by the board.

And as we mentioned initially, there are inhibitors of all sizes. From little more than a mobile to as large as a carry-on suitcase, always depending on the frequencies that you want to sweep (there are only one or several) and the range (from a few meters to more than a kilometer). And of course, if anyone wonders about the origin or beginnings of these devices, we would have to go back to war, specifically World War II, where both sides used inhibitors to interfere with enemy communications.

Why were their use banned or restricted?

It has happened with frequency inhibitors as with many other advances, technological ones included: there are always those who use it improperly. Frequency inhibitors can have legitimate uses such as protecting specific buildings or preventing the remote activation of explosives, for example, but there are many cases in which their use can be improper, even if the person using the inhibitor is not aware of it.

The case of universities

The case of universities

The use of inhibitors, for example, became popular a few years ago in several Spanish universities (Oviedo, Seville, Zaragoza, and Valencia are some examples). So that? As technology was being used in favor of students who prefer not to touch a book, through the use of earpieces connected to a person outside who facilitated exam answers, several teachers or faculties threw down the street in the middle, using frequency inhibitors that would prevent communication with the outside world.

There are several problems in these cases: the first is that the radius of action of the inhibitors is not controllable, beyond the power that determines the meters they can affect, so it could be harming users who are not present in the exam room. On the other hand, inhibiting all the frequencies that can be used in a mobile is not an easy task since they can vary depending on the operator of each mobile, or even a WiFi or Bluetooth network could be used for communication.

Alarms communicated by mobile network.

Another more than improper use that has been given to frequency inhibitors is for robberies at homes or other places. Alarms connected by mobile networks have recently become popular since they are easier to install and cheaper. The problem, in this case, is that the thieves could go to the place to be robbed with an inhibitor (alarms generally use the 900 MHz band) so that the alarm cannot communicate with the central.

Fortunately, alarm companies are aware that using the conventional mobile network is susceptible to being interfered with by frequency inhibitors (which, as we will see below, can be easily obtained over the Internet). For this reason, the first thing they recommend is either to install an alarm that communicates via a fixed network, obviously susceptible to cable cuts, or to use networks such as Sigfox’s, which, thanks to the use of an ultra-narrow frequency, is practically impossible to be inhibited.

What the law says about its use

What the law says about its use

Given these not-so-friendly uses of frequency inhibitors (and those we have not mentioned), the authorities had to take sides in using these devices. A report from the Central Private Security Unit of the Ministry of the Interior makes it clear if we can use inhibitors :

With the previous words, it is very clear that only the security forces of the State can make use of the inhibitors and the sanctions to which we expose ourselves in case of not paying attention to those words included in the General Telecommunications Law, go from 500,000 euros if it is considered a serious infringement and even up to 20 million euros if it is declared as a very serious infringement.

And Spain is not the only case of a country that prohibits its use since our law only transfers a European directive, although, for example, the United States also prohibited its use in its day. Even so, there are known cases of countries that, over time, have used jammers not only to protect themselves but also to prevent radio communications from abroad. On Wikipedia, you can explore more than one case.

And the sale of inhibitors?

It is unnecessary to be an Internet guru to access online stores without going to Chinese pages, where we can find inhibitors of all types and prices, but if their use is more than prohibited, can they be sold? We already know that, for some things, the laws on the network are quite blurred. Still, despite this, the European regulations are clear: they cannot be imported, marketed, installed, carry the CE certificate, and put into operation anywhere in the European Union.

However, as the Police report quoting the Secretary of State points out, “it must be taken into account that the Directive contemplates a series of equipment that are exempt from its application, such as those used exclusively for activities related to public security, national defense, state security and State activities in the field of Criminal Law”.

However, buying an inhibitor online is a very simple; you just need the money. In the first store, we found with a very simple search, they even have a section in which they supposedly answer the question about the legality of using inhibitors. Attention to the text, which has no waste :

The store above makes a living selling inhibitors, but they are hiding that inhibitors are illegal, including the legitimate uses they mention. As much as they defend the right to isolate private property from waves, controlling 100% of how far the effect of an inhibitor reaches is impossible, so it can affect beyond the desired area. In addition, the law is very clear; its use, import, and sale are illegal.