What Is Signal Jamming And How Does It Work?

For quite some time, the topic of signal jamming has been exclusively discussed on warfare forums and was only popular with a very specific audience. This took a complete turn, however, as technology continued to move forward with time. Especially with the rise of the use of mobile phones (fun fact: did you know that there are an estimated 3.5 billion smartphones in the world as of 2020?) technology supporting its services and functions has also blown up, one of which is signal jamming.

But what exactly is signal jamming and how does it work?

Signal jamming is the deliberate blocking and disruption of wireless communications. It’s a method that is used to mess with information flow and, in extreme cases, are used as a form of censorship.

The use of signal jamming can be traced as early as World War II. The method was utilized back then by ground radio operators to mislead pilots by transmitting false instructions, and governments used it as a way to stop its citizens from listening to radio broadcasts against their propaganda. At present, signal jamming is still used by the People’s Republic of China wherein the government plays broadcasting music (commonly Chinese folk music) to block broadcasting from stations like Radio Free Asia and Voice of Tibet.

Wave interference Explained

Wave interference plays a very important role in signal jamming. To understand it better, imagine throwing two rocks at still water. When you throw them at the same time, they create separate waves which, after meeting together, join to create a bigger wave. The same also happens for other waves like electromagnetic waves and sound waves.

Each wave comes with a corresponding frequency—to put simply, the number of times it pulsates. When a wave peaks and meets another wave which is also at its peak, it creates constructive interference which creates a new wave. However, when a wave trough merges with another wave trough, they automatically cancel each other and end up creating destructive interference instead.

The Science of Signal Jamming

Learning how wave interference works is important in understanding signal jamming. Consider a smartphone as an example, a gadget with a frequency that ranges between hundreds of megahertz to a few ones. Signal jamming a cellphone needs a destructive interference pattern with its radio waves. To do this, jamming devices have to flood a space with a radio wave that matches the phone’s frequency. Doing so will then create a white noise type of wave that can mess with the phone’s waves. When this is successful, any smartphone within the affected radius of that device will not receive any signal.

What is signal jamming used for?

Signal jamming may sound complicated, but it is actually quite useful for both consumer and government use. For example, many signal jammer devices are often used in prison centers to block possible sending out of messages from inside the area to the outside world. Since mobile phones are quite easy to smuggle inside prison facilities, there is a high chance that inmates can use it to communicate externally and create situations that can put witnesses and other civilians in danger.

Some types can be used to block signals of bombs and are commonly used for situations like VIP protection or prisoner transport, too. Military jamming equipment focused on this work by preventing detonation of improvised explosive devices, for example, by producing electronic countermeasures.

Of course, signal jamming gadgets can also be used for personal reasons as well. Everyone who has a smartphone has probably experienced getting annoying phone calls, something which a gadget like this can ultimately solve. Signal jammers for mobile phones mostly work to cover limited areas only—there are even portable models that you can take with you while you are on the move so you can protect yourself wherever you go. The Signal Jammer has several options of devices that can serve your needs, whatever they are.

Legal Issues

Many countries like the United States and the United Kingdom have set rules that make signal jamming against the law. In the U.S., specifically, smartphone jamming falls under the Communications Act of 1934 which cites that it is illegal for individuals to “willfully or maliciously interfere with the radio communications of any station licensed or authorized.” Importing, manufacturing, and selling of such devices are also deemed illegal.

For countries like this, using signal jammers equate to property theft, since blocking the signal in an area with a radio spectrum bought by a company is the same as stealing said property. Moreover, irresponsible jamming of signals can also be a safety hazard since it can affect other devices and get in the way of urgent information sharing.

On the other hand, some countries allow the use of signal jamming devices among government organizations and even private businesses. The reason behind this exception is because signals can pose more threats or interference to the operations of these agencies. Several examples are movie or concert theaters. Other countries make exceptions for the use of these devices during special events well.

Before purchasing a signal jamming device, it is necessary for the consumer or organization to verify first the legal restrictions of using it in their areas. In the U.S., fines, and prosecution for signal jamming are handled by the Federal Communications Commission which can either set a fine as high as $11,000 for a violation, or imprisonment for a year.

The low-down on signal jamming

Signal jamming doesn’t really have a clean image, especially with the history of the purposes for which it is used back then. However, that doesn’t mean that it doesn’t have any benefits. Looking at it with an unbiased point of view, it can bring as much good as it can with the bad.

It can block helpful signals for protection or it can also pose a risk when used for the opposite.

In the end, it is up to the user to practice responsible use of it and to make sure that it will only be used for legal reasons.

Meet Vishak, TechLog360's Content Editor and tech enthusiast. With a Computer Science degree and a passion for all things tech, Vishak delivers the latest in hardware, apps, and games with expertise. Trusted for his in-depth reviews and industry insights, he's your guide to the digital world. Off-duty, he's exploring photography and virtual gaming landscapes.


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