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Design And Construction Of A Remote Controlled Tri–band Frequency Jammer.
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CHAPTER TWO
LITERATURE REVIEW AND THEORETICAL FRAMEWORK
2.1 INTRODUCTION
Wireless networking plays an important role in achieving ubiquitous computing where network devices embedded in environments provide continuous connectivity and services, thus improving human’s quality of life. However, due to the exposed nature of wireless links, current wireless networks can be easily attacked by jamming technology. Jamming can cause Denial-of- Service (DoS) problem which may result in several other higher-layer security problems, although these are often not adequately addressed (Wood et al, 2007).
2.2 OVERVIEW OF JAMMER DESIGNS
Although network jamming is usually considered a critical threat, Gollakota and Katabi (2010) proved that jamming can be friendly too. They used jamming on the wireless channels instead of the physical layer as a defense to counteract eavesdropping attacks. Physical layer jamming is done by flipping certain bits in a packet such that a snooper cannot demodulate a legitimate signal. RF jammers are fairly simplistic devices. The simplest jammers have only an on/off switch and an LED signifying power to the unit. The more complex devices contain switches or dials that allow the user to select the frequencies desired for jamming. The components which can be located in every jammer include:
i. Antenna: The antenna transmits the jammers interrupting signal. Certain jammerscontain an internal antenna while others have external antennas which give the user a longer range to broadcast the signal and more control over frequency tuning.
ii. Voltage controlled oscillator: The oscillator is responsible for generating the competingradio signal.
iii. Tuning circuit: This unit enables the user to specify the frequency tuning. The tuningcircuit controls the broadcast frequency of the circuit by sending a specific voltage to the oscillator.
iv. Noise generator: The noise generator, which is part of the tuning circuit, actually createsrandomized electric output within a specific frequency range which is used to disrupt a cellular network signal.
v. RF amplification (gain stage): This amplifier controls the level of power to the tuningcircuit. It is responsible for boosting the power as necessary to jam signals.
vi. Power Supply: Smaller jamming devices may use batteries while larger and more powerintensive devices can be plugged into a standard outlet or connected through the electrical system of a vehicle.
2.3 JAMMERS TECHNOLOGY
Five types of devices are known to have been developed (or being considered for development) for preventing mobile phones form ringing in certain specified locations [16]
2.3.1 Type “A†Device (JAMMERS)
This type of device comes equipped with several independent oscillators transmitting ‘jamming signals’ capable of blocking frequencies used by paging devices as well as those used by cellular systems control channels for call establishment.
2.3.2 Type “B†Device (Intelligent Cellular Disablers)
Unlike jammers, it does not transmit an interfering signal on the control channels, the device, when located in a designated ‘quite’ area, functions as a ‘detector’. It has a unique identification number for communicating with the cellular base station.
2.3.3 Type “C†Device (Intelligence Beacon Disablers)
Unlike jammers, Type C devices do not transmit and interfering signal on the control channels. The device, when located in a designated ‘quite’ area, functions as a ‘beacon’ and any compatible terminal is instructed to disable its ringer or disable its operation, within the coverage area of beacon.
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ABSRACT - [ Total Page(s): 1 ]ABSTRACT COMING SOON ... Continue reading---
APPENDIX A - [ Total Page(s): 1 ]APPENDIX AList of Components• Vero Board • Connecting wire • Power Switch • 30 Amps Fuse • Soldering Lead • Soldering Iron • LEDs • 240V/ 60V Transformer • 12 volts D.C battery • • IN9004, IN4004.1 diode, • 750 Ω, 750.1Ω, 100Ω, 1KΩ, 2KΩ, 22KΩ, 100KΩ, 1KΩ, 2KΩ, 22kΩ resistors • 555 timer • ... Continue reading---
APPENDIX B - [ Total Page(s): 2 ] ... Continue reading---
CHAPTER ONE - [ Total Page(s): 2 ]CHAPTER ONEINTRODUCTION1.1 BACKGROUND OF THE STUDYA mobile phone jammer or signal blocker is an instrument used to prevent cellular phones from receiving signals from base stations. The process of blocking the receiver to receive a transmitted signal is called Jamming of the signal. The jammer effectively disallows cellular phone signal when activated. These devices can be used in practically any location, but are found primarily in places where a phone call would be particularly disruptiv ... Continue reading---
CHAPTER THREE - [ Total Page(s): 11 ]The operation of power supply is as shown:The transformer which transforms 220V AC to other levels of voltages. Its functions are outlined below:i. Rectification: Convert the AC voltage to DC voltage.ii. Filtering: “Eliminate the noise†so that a constant DC voltage is produced. This filter is just alarge capacitor used to minimize the ripple in the output.iii. Voltage Regulation: It provides the desired DC voltage.The step down transformer steps down the input volt ... Continue reading---
CHAPTER FOUR - [ Total Page(s): 5 ]The bar chart in figure 4.9 above shows the jamming strength of the jammer at Eigbejila, Odota and Garin Alimi area of Ilorin west Local government area kwara State, Nigeria. It is obvious from table 4.2 above that as the distance between the cell phone and the base station increases, the effective jamming distance increases. This is due to the fact that the amount of power reaching the cell phone from the base station decreases as the cell phone moves farther from the base station and vice ve ... Continue reading---
CHAPTER FIVE - [ Total Page(s): 1 ]CHAPTER FIVECONCLUSION, CHALLENGES, RECOMMENDATION 5.1 ConclusionsThis project is very useful for mobile phones restricted places such as private meetings, examination hall, defense establishments, military camp, Hospitals; Petrol pumps, Libraries etc. This device can scramble/jam mobile devices in a given area within the operating frequency range of 800MHz - 2100MHz at the range of 2-7 meters. The designed device works in Tri-band. It jams the GSM 800 band, GSM 1800 band and the add ... Continue reading---
REFRENCES - [ Total Page(s): 1 ]REFERENCES1. Science Journal of Physics ISSN: 2276-6367 http://www.sjpub.org/sjp.html.2. Radio Jamming", Wikipedia Foundation, Inc. 2012. 3. "Electronic Warfare", Wikipedia Foundation, Inc. 2012. 4. "Electronic Counter-Countermeasures", Wikipedia Foundation, Inc. 2012. 5. Scourias, John (1997): Overview of the Global System for Mobile Communications, University of Waterloo.6. "Mobile Phone Jammers", Wikipedia Foundation, Inc. 2012.7. Semiconductor device ... Continue reading---
