As our reliance on wireless technology continues to grow, we find ourselves constantly connected to our devices. From checking emails to unlocking our cars with key fobs, and relying on GPS to navigate to new destinations, our daily lives are heavily dependent on wireless communication. This dependency also extends to large-scale infrastructure, such as military and civilian operations. Unfortunately, wireless signals are vulnerable to interference from signal jammers, which pose a significant threat to our ability to maintain connectivity.

The Functioning Mechanism of Signal Jammers？

Typically, signal jammers operate by generating high-powered noise, tones, or pulses that overpower existing wireless signals. By tuning a jammer to a specific frequency range, nearby receivers attempting to listen on that frequency can be interrupted. This disruption has traditionally been limited to radio communications, but the same principle is applicable to other wireless signals, including WiFi, Bluetooth, GPS, and cellular signals. The jammer’s effective range depends on the device’s power and scale, with a small handheld jammer being able to disrupt signals within a 100-meter radius in an urban environment. In contrast, military-grade jammer emplacements can reach hundreds of miles across open terrain.

The Military and Paramilitary Applications of Signal Jammers

Jamming technology has a long history of military and paramilitary use, with the earliest and most notable examples of jamming occurring during World War II. The Nazi regime used jamming technology to disrupt Allied radio transmissions in occupied Europe, which led to the development of countermeasures and ultimately to the evolution of more advanced forms of jamming technology.

Jamming technology continued to be utilized extensively throughout the Cold War, with both the Soviet Union and China jamming incoming signals from the United States and other Western nations. Cuba, in particular, was known for blocking American radio stations during this time, while North and South Korea engaged in a constant back-and-forth of jamming each other’s transmissions.

Jamming technology and its military applications have evolved significantly since the early days of World War II. Modern signal jammers can be used to disrupt a wide range of wireless signals, including cellular networks, GPS systems, and Wi-Fi. They can be used to limit an adversary’s ability to communicate or navigate, or to create confusion on the battlefield. Jamming technology can also be used to prevent remote detonation of improvised explosive devices (IEDs) by jamming the signal used to trigger the explosive.

While signal jammers remain an important tool in the military and paramilitary arsenal, their use is not without controversy. Jammers can disrupt legitimate civilian communications and can also interfere with friendly forces’ communications and navigation systems. Additionally, the use of signal jammers in some situations may be seen as a violation of international law. As such, their use requires careful consideration and planning to avoid unintended consequences.

A Russian Krasukha-2 anti-air jamming station. (Photo via Mil.ru, CC 4.0)

Signal jammers continue to be a frequently used tool in electronic warfare (EW), particularly by the Russian military. There have been reports of Russian interference with low-altitude U.S. surveillance drones during the Syrian conflict in 2018, although it remains unclear if that caused the drones to crash or simply deviate from their intended course. Additionally, Russia has been using powerful jammers along its eastern border, which has resulted in disruptions to Latvia’s phone system and loss of GPS signals to aircraft in the vicinity.

Mexican drug cartels have also been using signal jammers extensively as a part of their operations. This technology is often utilized alongside another popular tool among the cartels: aerial drones. The signal jammers disrupt the signals between the drones and their operators, making it much harder to track or intercept them. This has allowed the cartels to conduct surveillance, deliver drugs, and even smuggle individuals across borders with an increased level of security and ease.

However, the use of signal jammers also poses a significant threat. It interferes with legitimate communications and may put innocent lives in danger. For example, jammers used to block drone signals near critical infrastructure or airports could create accidents or disrupt emergency services. Consequently, the usage of signal jammers in all contexts requires careful consideration of the potential hazards and consequences.

Armed members of the Jalisco New Generation Cartel (CJNG) wearing signal jammers. (Screenshots via @just_some_d00d

Small commercially-available drones have been used to surveil territory, especially at night with the aid of thermal cameras. They have also been weaponized to drop explosives on targets, a tactic that has previously been used by ISIS and other terrorist organizations in the Middle East. As a result, cartel members have been seen wearing man-portable signal jammers that can interfere with nearby drone uplinks as well as cellular and radio comms.

Criminal Misuse and Civilian Black Market Usage

An example of a portable signal jammer available for sale on the internet, listing the frequencies it claims to block.

At this point, you may be thinking, “I’m not a high-value military target or part of a warring drug cartel, so I shouldn’t have any reason to care about signal jammers.” However, this is certainly not the case. Signal jammers are inexpensive, easy to use, and readily available online to those who know where to look. They can affect your daily life in several ways — veteran-owned surveillance gear manufacturer Tiny Transmitters posted some surprising demonstrations on Instagram to prove this point.

The first demo video clip shows how a portable jammer can be tuned to the frequency of a car keyfob, blocking its signal at the flip of a switch. This means a thief could watch you park your car, turn on the jammer before you press the lock button on the fob, and prevent your car from locking. Unless you happened to notice the absence of a click or light flash from your vehicle, you’d probably assume it locked and walk away, allowing the criminal to steal any valuables in the car (or take the car itself).

Tiny Transmitters showed how a signal jammer can be used to disable a wireless doorbell camera.

Another video shows how a jammer can be used to interrupt a wireless doorbell camera by blocking its ability to communicate with the home’s WiFi network. Unless the camera has a hardwired data connection — unlike most Ring, Blink, Wyze, and Nest doorbell cams — it will be unable to transmit footage to cloud servers or alert the homeowner that someone is at the door. Tiny Transmitters explains, “As you can guess, running an all-wireless household security system has a fundamental and scary flaw: the wireless signal can be jammed.”

There are many other possible applications of wireless signal jammers, from covertly blocking cell phone calls to disabling GPS tracking devices. These uses are illegal, but as we know, motivated criminals are unlikely to give a second thought to laws and FCC regulations.

CLOSING THOUGHTS

We’re not advocating for people to forego the use of WiFi, dispose of their cell phones, or abandon their ham radios. Wireless devices are convenient and can be essential in emergency situations. Nevertheless, it’s crucial to recognize their potential vulnerabilities and take precautionary measures to prevent over-dependence on wireless devices for the safety of ourselves and our possessions.