You have probably heard about signal jamming in spy movies or about when states use them for media censorship. But jamming can also be an attack from a neighbor or hacker.

The way signal jamming works makes it very isolating for victims, meaning they're cut off from the internet or even regular phone service. The attack is also difficult to defend against. Nevertheless, there are several things you can do if you find yourself the target of signal jamming.

What Is Signal Jamming?

Signal jamming is the act of disrupting the connection between a device and its access point in a wireless connection. This makes signal jamming a type of Denial of Service (DoS) attack—because devices in the area cannot access the internet while jamming is active.

The use of signal jamming ranges from privacy reasons (when a person or company wishes to prevent the use of internet-enabled devices on their property) to state censorship and cyberattacks.

How Does Signal Jamming Work?

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Devices on a wireless network send and receive information using data packets at a specific frequency. Signal jamming involves using a jammer to send “noise” that disrupts the frequency band on which wireless devices operate.

A signal jammer can be a hand-held, portable device that prevents wireless communications within a 15-meter radius. Portable jammers can be purchased or self-made. These jammers are relatively cheap, disrupt communication on specific frequencies, and are mostly used for personal privacy and security reasons.

Conversely, stationary jammers are made to be installed in a building or mounted on a platform. Stationary jammers can affect a wider area and disrupt wireless communications on a broad range of frequencies, including blocking drones. These features make stationary jammers more expensive, energy-demanding, and, thus, suitable for enterprise purposes.

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No. Individual possession and use of signal jammers in the United States is illegal, per Sections 302(b) and 333 of the Communications Act of 1934. This law prevents individuals, businesses, and even local law enforcement from using jammers. Federal law enforcement agencies are permitted under specific circumstances but must obtain judicial approval first.

The main reason for this prohibition is that signal jamming can endanger public safety, regardless of the intent. Besides personal communication, signal jamming can also interfere with emergency services.

Tampering with wireless communication is a federal offense, as per the Communication Act. Anyone who sells, buys, or uses a signal jammer in the US faces criminal and civil liabilities. But the threat of penalties has never stopped cybercriminals, has it?

What Can You Do Against Signal Jamming?

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Most people wouldn’t know their connection has been jammed because everything else would look alright. Cell phones will have reception, and the router will show it’s working perfectly. The problem is, a jammer disrupts wireless transmission between devices and their access points. So, what can you do in this case?

Change Your Location

Odds are, the signal jammer is one with a five to 15 meter jamming radius. So, consider moving from where you are if you can. This way, you can even meet other people and ask if their internet connection is active.

Change Your Wi-Fi Frequency

You will find instructions on how to change your router's broadcasting frequency in the device manual. But odds are you tossed this manual away a long time ago. In that case, you will need to log in to the admin dashboard of your router and check the Wi-Fi settings.

The two frequency bands used for wireless connections are 2.4 GHz and 5.0 GHz, with most modern devices supporting both bands. Most portable jammers disrupt connections operating on the 2.4 GHz band. Changing your WiFi frequency to 5.0 GHz would help you avoid the DoS attack on the 2.4 GHz band.

However, there is a con: the 5.0 GHz band supports higher speeds but has a shorter range. You would need to be closer to the router as the signal cannot easily penetrate solid objects like walls. Although effective at avoiding the DoS attack, the range restriction makes changing your Wi-Fi frequency a temporary measure.

Change Your Wi-Fi Frequency Channel

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This measure is a long shot compared to changing your Wi-Fi frequency entirely. However, it’s worth a try, especially if your device does not support higher frequencies.

Devices that broadcast on the 2.4 GHz frequency have 11 to 13 channels, with each separated by about 5 MHz. On the other hand, the 5.0 GHz frequency has 25 channels, each separated by at least 20 MHz and up to 160 MHz.

Switching channels is a tricky thing to do, especially on the 2.4 GHz frequency. You want to avoid interference from overlapping channels. The small channel width on the 2.4 GHz frequency makes interference from overlapping channels very likely. Conversely, the wider channel widths on the 5.0 GHz frequency mean you’re less likely to have this problem.

Find and Remove the Jammer

Finding the signal jammer is another viable option when all others have failed. However, it’s still a long shot, especially because it’s easy to hide a potable, palm-size signal jammer.

Still, finding and removing the jammer is worth a try because you know you only have to search within a 15-meter radius. The attacker would most likely be in your vicinity, and you can look around for a radio-like device with an antenna. Your chances reduce if the jammer is in a backpack or in the neighboring apartment, for example, because you can’t search private property without trespassing.

Meanwhile, your chances of finding a stationary jammer with a wider range are much slimmer. However, it is unlikely that an attacker would use such a jammer because it would affect more people and public infrastructure, thereby drawing unwanted attention from law enforcement.

Call Your Service Provider

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Your inability to access the internet could be due to a problem with your Internet Service Provider (ISP). Your ISP could have disconnected your service for unpaid bills or violated its Terms of Service. Your ISP may also have service downtime due to an upgrade, faulty equipment, or bad weather. You should call your ISP to confirm that your service is still active.

It Could Be Something Else Besides Signal Jamming

Signal jamming is a less common type of DoS attack because federal law prevents the manufacture, import, and sale of jammers in the United States. So, your inability to access the internet could be the result of other types of DoS attacks like a disassociation attack.