What is Radio Frequency Jamming
Radio jamming is the deliberate transmission of radio signals that disrupt communications by decreasing the signal-to-noise ratio. Unintentional jamming occurs when an operator transmits on a used frequency without checking, equipment generating radio noise, etc.
The history of jamming radio frequency is nothing new and was first used during the second world war. The use of radio jamming for military radios is still used worldwide. It is often used in company boardrooms and banks to prevent the public or criminals from using their cellular devices to receive or transmit data. A transmitter, tuned to the same frequency as the opponents’ receiving equipment and with the same type of modulation and with enough power, can override any signal at the receiver.
Jamming has now become a very real threat in the intruder alarm industry worldwide as more and more frequency jammers are being produced and used in criminal activity. Some countries are reporting up to 30 successful jamming attempts per day in shopping mall parking areas, on vehicle locking systems. The jamming of wireless alarm systems and GSM Communicators is on the increase.
- The public are often left facing a financial loss with no claims from their insurance companies, after a non-forced entry theft from motor vehicles.
- An alarm system can be fully functional during and after a break-in, yet during frequency jamming no signals were received by the Central Station.
- Wireless video systems can malfunction due to Wi-Fi links being blocked during criminal activity due to Wi-Fi jammers being used. From simple devices such as wireless remote arming keyfobs to sophisticated RF and GSM jamming devices, these products pose a definite threat to any wireless device.
Commonly Jammed Frequencies
The most commonly jammed frequencies worldwide are the short range open, unlicenced frequencies and particularly in the 400mHz – 433mHz band which is used in many countries.
This frequency, which is considered the most congested and overcrowded frequency in the world, is used in wireless intruder alarm systems, Remote arming keyfobs, wireless panic switches, gate and garage door automation, remote controlled cars and baby monitors. As this frequency is generally open and unlicenced, it can be used by anyone for anything.
Simple Vehicle Jamming
The simplest and most effective use of jamming is in vehicle locking systems and wireless intruder alarm systems. No sophisticated or expensive equipment is required and criminals are using the very same devices we are using in our alarm systems or vehicle locking systems.
By keeping the button continually depressed on a handheld wireless remote or keyfob using the same frequency as the system, it can successfully override the frequency while a vehicle is in the process of being locked. As two of the same frequencies cannot be transmitted at the same time, the person attempting lock their vehicle is under the impression that the vehicle is locked and walks away giving criminals the opportunity to gain access and steal goods.