Know how cell-phone jammers work
You need to know about the legality of the use of cell phones jammers. Disrupting a cell phone is similar to jamming any other type of radio communication. A cell phone communicates with its service network through a cell tower or its base station. Cell towers have divided a city into small areas. As a cell-phone user is driving down the street, the signal gets handed from tower to tower.
These cell phones jammers transmit on the same radio frequencies as the cell phone. The cell phones jammers disrupt the communication between the phone and the cell-phone base station in the tower.
This is also called a denial-of-service attack. The cell phones jammers deny service of the radio spectrum to the cell-phone user within the range of the jamming device. The cell phones jammers are able to overpower the cell phone by transmitting a signal on the same frequency s well as at a high enough power so that the two signals tend to collide and cancel each other out. Cell phones have been designed to add power in case they experience low-level interference. The cell phones jammers must recognize this and match the power increase from the cell phone.
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Cell phones use two separate frequencies. While one is for talking and one is for listening simultaneously. Some cell phones jammers block only one of the frequencies that are used by cell phones, which actually have the effect of blocking both. The cell phone is tricked into thinking that there is no service as it can receive only one of the frequencies.
Less complex cell phones jammers block only one group of frequencies, while the sophisticated cell phones jammers can block several types of networks at once. This helps to head off dual-mode or tri-mode phones which tend to automatically switch among different network types in order to find an open signal. Some of the high-end cell phones jammers block all frequencies at once, and other cell phones jammers can be tuned to specific frequencies.
In order to jam a cell phone, all that you need is a device that is able to broadcast on the correct frequencies. Even though different cellular systems tend to process signals differently, all the cell-phone networks use radio signals that can be interrupted. The cell phones jammers can broadcast on any frequency. They are effective against AMPS, CDMA, TDMA, GSM, PCS, as well as DCS, iDEN and Nextel systems.
