Dual band mobile jammer for GSM 900 MHZ &GSM 1800 MHz
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Date
2011-03-24
Journal Title
Journal ISSN
Volume Title
Publisher
UMT Lahore
Abstract
This report represents the design and implementation of a device that transmits on the same radio frequencies as a cell phone, disrupting the communication between the phone and the cell-phone base station in the tower. Jamming devices overpower the cell phone by transmitting a signal on the same frequency as the cell phone and at a high enough power that the two signals collide and cancel each other out.
Cell phones are designed to add power if they experience low-level interference, so the jammer must recognize and match the power increase from the phone. Some jammers block only one of the frequencies used by cell phones, while sophisticated jammers can block several types of networks at once to head off dual-mode or tri-mode phones that automatically switch among different network types to find an open signal.
Communication jamming devices were first developed and used by the military. Nowadays, mobile jammer devices are becoming civilian products rather than electronic warfare devices. With the increasing number of mobile phone users, the need to disable mobile phones in specific places where ringing would be disruptive has increased. These places include places of worship, university lecture rooms, libraries, concert halls, meeting rooms, and other places where silence is appreciated.