A GSM jammer or cell phone jammer is a device that sends signals on the same frequency as the GSM system. If the mobile phone is disabled in the area where the interference source is located, the failure is successful. The communication jammer was first developed and used by the military. When tactical commanders use radio frequency communications to control their armed forces, the enemy will be interested in such communications. This interest comes from the basic field of refusing to successfully transfer information from the sender to the receiver.
Today, compared with electronic warfare equipment, mobile jammer devices or mobile phone jamming software are becoming civilian products. With the increase in the number of mobile phone users, the need to disable mobile phones in some places that may cause the interruption of mobile phone ringing is also increasing. Big. These places include places of worship, university lecture halls, libraries, concert halls, conference rooms and other places where silence is important
Interfering devices flood the mobile phone by sending signals at the same frequency as the mobile phone, and with sufficient power to cause the two signals to collide with each other and cancel each other out. Mobile phones are designed to increase power with little interference. Therefore, the jammer must recognize and adjust the performance improvement of the mobile phone. Mobile phones are full-duplex devices, which means that they use two separate frequencies, one for talking and one for listening at the same time. Some jammers block only one of the frequencies used by mobile phones, and both frequencies block.
The phone was tricked into thinking that there was no service because it could only receive one of these frequencies. Less complicated devices can only block a set of frequencies, and complex portable jammer can block multiple network types at the same time to turn off dual-mode or triple-mode phones, and these phones will automatically switch between different network types to find the open one. signal. Some high-end devices block all frequencies at the same time, while other high-end devices can be tuned to certain frequencies.
To interfere with your phone, all you need is a device that transmits on the correct frequency. Although different cellular systems process signals differently, all cellular networks use radio signals that can be interrupted. GSM, which is used in digital cellular and PCS-based systems, operates in the 900 MHz and 1800 MHz bands in Europe and Asia and in the 1900 MHz band in the United States (sometimes referred to as 1.9 GHz). The jammer can be transmitted on any frequency and is effective for AMPS, CDMA, TDMA, GSM, PCS, DCS, iDEN and Nextel systems. Old analog phones and today’s digital devices are equally vulnerable to interference. Interrupting a cell phone is equivalent to interrupting another type of radio communication. A mobile phone communicates with its service network through a base station or base station. The communication tower divides the city into small areas or units. When mobile phone users drive along the street, the signal passes from one tower to another
The jamming device transmits on the same radio frequency as the mobile phone and interrupts the communication between the mobile phone and the city’s mobile phone base station. This is called a denial of service attack. The jammer refuses to provide radio spectrum to mobile phone users within the interference range. Sometimes older jammers are used.
Only applicable to phones that use only analog or older digital mobile phone standards. Newer models such as dual-band and tri-band jammers can block all widely used systems (AMPS, iDEN, GSM, etc.), and are very effective even for new mobile phones that jump to different frequencies and systems under interference. Because popular network technologies and mobile phones use different frequencies around the world, some only work in certain regions (such as Europe or North America).
The intensity of the interference effect may vary depending on many factors, such as the distance from the tower, indoor and outdoor environments, the presence of buildings and landscapes, and even temperature and humidity all play an important role. People worry that rough-designed jammers will interfere with the functions of pacemakers and other medical devices. However, like mobile phones, the most commonly used devices operate at low enough power (<1W) to avoid problems.
In this device, we overwhelm the signal from the mobile phone with a stronger signal. This type of device is equipped with several independent oscillators that send “interference signals”, which can prevent the frequency used by the paging device and the frequency used by the mobile radio/PCS system control channel. When such devices are active in a specific area, they (through RF interference) prevent all pagers and cell phones in the area from receiving and sending calls. This type of device only transmits interfering signals, and the frequency selectivity is very poor, which causes interference to a communication spectrum that is larger than originally expected. Technical expert Jim Mahan said: “There are two types. One is called brute force interference, which only blocks everything. The problem is that the air waves are washed by electricity and enter the public broadcast area. The other removes a small amount of interference , You can limit it to a single cell. You can use many small bags with little interference to control the facility.”