What is Jammer?
- Cell phone jammers are devices that create a temporary “dead zone” to all cell phone traffic in their air system.
- A cell phone jammer is an instrument used to prevent cellular phones and their mobile signals to a base station. When used, the jammer effectively disables cellular phones in the area.
- Other types of jammers -radar jammer and radio jammer.
Size of Jammer:
Some cell-phone jammers are made to look like actual phones. Others are briefcase-sized or larger. The biggest jammers used by police and the military can be mounted in vehicles for convoy security.
Why Jammers are used?
- Cell phone jamming devices were originally developed for law enforcement and the military to interrupt communications by criminals and terrorists.
- Examples include: security zones public transport,classrooms,temples,jails,govt.buildings,military bases, industries etc.
How Jammer Works:
A jamming device transmits – same radio frequencies as the cell phone, the communication between the phone and the cell-phone base station in the tower. It’s a called a denial-of-service attack.
- Jammers block cell phone use by sending out radio waves along the same frequencies that cellular phones use at a high enough power that the two signals collide and cancel each other out.
- This causes interference with communication of cell phones and towers to render the phones unusable.On most phones, the network would be out of range.
What is Inside the jammer?
Every jamming – antenna to send the signal. Some are contained within an electrical cabinet. On stronger devices, antennas are external to provide longer range and may be tuned for individual frequencies.
Smaller jamming – battery operated.
Some look like cell phone and use cell-phone batteries. Stronger devices – plugged into a standard outlet or wired into a vehicle’s electrical system.
The main electronic components of a jammer are:
Voltage-controlled oscillator – Generates the radio signal – interfere with the cell phone signal.
Tuning circuit – Controls the frequency at which the jammer broadcasts its signal by sending a particular voltage to the oscillator.
Noise generator – Produces random electronic output in a specified frequency range to jam the cell-phone network signal.
RF amplification (gain stage) – Boosts the power of the radio frequency output to high enough levels to jam a signal.
Applications of jammer?
- Cell phone jamming devices were originally developed for law enforcement and the military to interrupt communications by criminals and terrorists
- It has been widely reported that a cell-phone jammer thwarted an assassination attempt on Pakistani President Musharraf in December 2003.
- Used in areas where radio transmissions are dangerous, such as areas with a potentially explosive atmosphere, such as chemical storage facilities or grain elevators.