A Mobile jamming device is an instrument used to avert mobile phones from receiving the signal from their network stations. A jammer deteriorates the cell network.
The signal in our cell phone transmits a frequency of 800MHz (approx.). A jamming device transmits frequency and power of the same magnitude. As a result, when both the signals collide, they oppose or cancel each other, and our mobile phones receive no signal. A jammer is so equipped that it can change its frequency and power in accordance to the cell phone in range.
A jammer can broadcast any frequency and can also work against AMPS, CDMA, TDMA, GSM, PCS, DSC, iDEN, and Nextel systems. As most cell phones use radio signal, it is generally easy to intercept or block them.
There are five types of jammer:
1. Type “A” device: Jammers
2. Type “B” device: Intelligent Cellular Disablers
3. Type “C” device: Intelligent Beacon Disablers
4. Type “D” device: Direct Receive and Transmit Jammers
5. Type “E” device: EMI Shield- Passive Jamming
In this device, the cell phone network is blocked with a frequency higher than the common cell phone network. It can obstruct a normal digital mobile phone and a pager.
INTELLIGENT CELLULAR DISABLERS
This device, unlike the Jammers, acts as an indicator. When a mobile phone user is accessing his/her phone to connect to base, the detector/indicator finds the connecting signal as well as the connecting device. The device then informs the base not to communicate with the target device and also points the location of the target device.
INTELLIGENT BEACON DISABLERS
This device acts as a Beacon, which means it transmits a signal which guides the cell phone to operate itself. When a mobile phone is being used within the range of this device, the beacon instructs the phone to change its operation mode. For example, if the phone is not switched off then it instructs it to do so.
DIRECT RECEIVE AND TRANSMIT JAMMERS
Such jammers are used as small base stations. Its design is such that when a mobile phone in its range is transmitting any signal, it can intercept the signal and connect to the device as the base station.
EMI SHIELD-PASSIVE JAMMING
This device diverts even the emergency signals and can block, decode or receive those signals.
Thus a jammer is used in restricted places where the cell phones are not allowed. These devices are used in Military bases, Schools, Theatres, etc. In most countries, the use of these devices in public places is strictly prohibited. These devices are used with proper license and rules. The use of jammers is not allowed as they can also be used for illegal purposes. The mobile phone jamming device works well when people have forgotten to switch off their phones.