Cell phones are everywhere these days. According to the Cellular Telecommunications and Internet Association, approx. 1000 million people in India had cell-phone service. Due to wide use of mobile phones it creates some problems as the sound of ringing becomes annoying or disrupting. A cell phone jammer is a device that blocks transmission or reception of signals, usually by creating some form of interference at the same frequency ranges that cell phones use. As a result, a cell phone user will either lose the signal or experience a significant loss of signal quality.

1. CELL PHONE JAMMER
Presented by:-
Name- Aditya Kumar Tripathy
Regd. No.- 1241019150
Section- A

2. CONTENTS
• Introduction
• Jamming Techniques.
• Design Parameters.
• Components of the Jammer device.
• How mobile Jammer works?
• Applications.
• Conclusion.
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3. INTRODUCTION
• Cell phones are everywhere these days. According to the Cellular
Telecommunications and Internet Association, approx. 1000 million people in
India had cell-phone service.
• Due to wide use of mobile phones it creates some problems as the sound of
ringing becomes annoying or disrupting.
• A cell phone jammer is a device that blocks transmission or reception of
signals, usually by creating some form of interference at the same frequency
ranges that cell phones use.
• As a result, a cell phone user will either lose the signal or experience a
significant loss of signal quality.
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4. IMAGE
Mobile jammer blocking signals in a meeting. Image courtesy: [1]
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5. JAMMING TECHNIQUES
1. Spoofing.
2. Shielding Attacks.
3. Denial of Service .
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6. DESIGN PARAMETERS
1. Distance to be Jammed(D).
2. Frequency Bands.
3. Jamming-to-signal ratio{J/S} :-
• Jamming is successful when the jamming signal denies the usability of the
communication transmission.
UPLINK DOWNLINK
GSM 900 890-915 MHz 935-960 MHz
GSM/DCS 1800 1710-1785 MHz 1805-1880 MHz
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7. DESIGN PARAMETERS
(Continued)
• A successful jamming attack requires that the jammer power is
roughly equal to signal power at the receiver (mobile device).
• The general equation of the jamming-to-signal ratio is given as
follows:
𝐽
𝑆
=
𝑃𝑗 𝐺𝑗𝑟 𝐺 𝑟𝑗 𝑅𝑡𝑟
2
𝐿 𝑟 𝐵𝑟
𝑃𝑡 𝐺𝑡𝑟 𝐺 𝑟𝑡 𝑅𝑗𝑟
2
𝐿𝑗 𝐵𝑗
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8. DESIGN PARAMETERS
(Continued)
4. Free space loss {F}:
The free-space loss (or path loss) is given by:
Path loss (db) = 32.44 + 20 log d (km) + 20 log f (MHz).
• The maximum free space loss (worst case F) happens when the maximum
frequency is used in the above equation.
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9. COMPONENTS OF THE JAMMER
DEVICE
 The simplest just have an on/off switch and a light that indicates it's on.
 Complex devices have switches to activate jamming at different frequencies.
 Main Components :
 Power Supply
 Circuitry
 Antenna
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10. COMPONENTS (Continued)
Jammer consists of 3 main blocks.
Power
Supply
IF- Section RF- Section
Jamming
Signal
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11. COMPONENTS (Continued)
1. The IF-Section :-
i. Triangle wave generator.
ii. Noise generator.
iii. Mixer “Summer”.
2. The RF-Section :-
i. The voltage controlled oscillator(VCO).
ii. The power amplifier.
iii. The antenna.
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12. HOW CELL PHONE JAMMER
WORK ?
• Cell phone jammers work in a similar way to radio jammers by sending out the same radio
frequencies that cell phones operate on.
• This creates enough interference so that a call cannot connect with a cellphone.
• 2 types of jammers. The first type are usually smaller devices that block the signals coming
from cell phone towers to individual cell phones.
• Can block signals within about a 30-foot radius. Cell phones within this range simply show no
signal.
• The second type of cell phone jammer is usually much larger in size and more powerful.
• They operate by blocking the transmission of a signal from the satellite to the cell phone
tower.
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13. HOW JAMMER WORK ? (Continued)
Image courtesy: [1]
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14. HOW JAMMER WORK ? (Continued)
Mobile phone intelligent jamming system block diagram
Triangular
wave Gen.
Noise Gen.
MIXER VCO
Mobile
Detector
PIC
16F84
Power Amp.
Power Amp
Synthesizer
RF
Switch
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15. Image courtesy: [1]15

16. APPLICATIONS
1. To maintain the complete silence in library and lecture hall
2. To avoid fraud in examination hall.
3. To avoid disturbance in class room.
4. For providing security in business conference, board of directors rooms, seminars, etc.,
5. For providing calm and peaceful atmosphere in Hospitals
6. The jammer also stops Internet use through Wi-Fi network and even blocks Bluetooth
connections.
7. The cell phone signal jammer also puts an end to text messaging, so students cannot SMS
each other, while the teacher is trying to teach.
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17. FUTURE SCOPE
•While the law clearly prohibits using a device to
actively disrupt a cell-phone signal, there are no rules
against passive cell-phone blocking.
•Companies are working on devices that control a cell
phone but do not "jam the signal.
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18. CONCLUSION
• We can say every device is acts as good aspects as well as bad
aspects.
• Operating or even owning a cell phone jammer is illegal in most
countries.
• Jamming is seen as Property Theft, Safety Hazard.
• In many place cell phone jammer is useful but at many place it is a
problem .
• But it’s overall performance is very good and helpful in our life.
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19. REFRENCES
[1] Ibrahim Patel, Ragha vedra Kulkarni, Junaid Ali Khan, “INTELLIGENT FM
SIGNAL JAMMING SYSTEM”,IEEE Third International Conference on
Computing, Communication and Networking Technologies (ICCCNT'12),26th -
28th July 2012.
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