MOBILE JAMMERPRESENTED

By

A. VENKATESH(11BG1A05B2)

Under the esteemed guidance of

T. NAGA LAKSHMI Assistant Professor

Dept. of Computer Science and Engineering

SRI VENKATESWARA INSTITUTE OF SCIENCE AND TECHNOLOGYKadapa

CONTENTS• Introduction•Components of Mobile Jammer•Mobile Jamming Techniques•Design Parameters / Specification of mobile

jammer•Block Diagram of Mobile Jammer•Applications• Legal Issues and Alternatives of Mobile Jamming•Conclusion

Why mobile JAMMER is needed?•A mobile Jammer is an instrument which is used to

prevent mobile phones from receiving signals from the base stations Which can be used in practically at any location but are mostly found in places where a phone call would be particularly disruptive because silence is expected.

Components of Mobile Jammer

Voltage Controlled oscillator (VCO)

Tuning Circuit Noise Source RF-Amplification unit Transmitting Antenna

Voltage Controlled Oscillator•VCO is like heart of our jammer.•VCO produces RF signal which will interact with the blocked device.•We must select frequencies which Will be used in our Signal blocking device.

Tuning circuitTuning circuit can be of two types: Open-loop FeedbackOpen-loop is a saw tooth-wave generator which makes VCO to go from lowest to highest frequency.

The feedback is used to adjust the VCOs frequency constantly.

Noise generator • Produces random electronic output in a specified frequency range to

jam the cell-phone network signal (part of the tuning circuit)

RF Amplification Unit• RF Amplification Unit is what we need when we wish to increase the

area covered by our jammer along with its signal blocking power. Transmitting Antenna

• Transmitting Antenna is a tool which transmits signals produced by your jammer. The main characteristic of antenna is VSWR (Voltage Standing Wave Ratio).

Power Source• Power Source makes our creation to become alive. Generally mobile

phone jammers use 5V of DC to operate.

Mobile Jamming TechniquesThere are various types of jamming devices available which are using different jamming techniques.

Type "A" Device Type "B" Device Type "C" Device

Type "D" Device Type "E" Device

Type "A" deviceType "A" devices are simple jammer. 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.Type "B" deviceType "B" devices are also known as INTELLIGENT CELLULAR DISABLERS. The device, when located in a designated quite area, functions as a detector.Type "C" deviceType "C" devices are also known as INTELLIGENT BEACON DISABLERS.Unlike jammers, type c devices do not transmit an interfering signal on the control channels.

Type "D" deviceType "D" devices are DIRECT RECEIVE TRANSMIT JAMMERS. This jammer behaves like a small, independent and portable base station, which can directly interact intelligently or unintelligently with the operation of the local mobile phone.Type "E" deviceType "E" devices are used for EMI Shield - Passive Jamming. This technique is using EMI suppression techniques to make a room into what is called faraday cage

Design Parameters / Specification of mobile jammer

The frequency bands

Distance to be jammed (D) Pj Gjr Grj R2

tr Lr Br

Jamming–to-signal ratio {J/S}= Pt Gtr Grt R2jr Lj Bj

Free space loss {F}= Path Loss (dB)= 32.44 + 20 log D(km) + 20log f(MHz)

Power calculations

The layout of the jammer

Block Diagram of Mobile Jammer

• Power Supply

IF Section

RF Section

Mobile jammer

Applications• To maintain the complete silence in library and lecture hall• To avoid fraud in examination hall • To avoid disturbance in class room. • For providing security in business conference, board of directors

rooms, seminars, etc.• For providing calm and peaceful atmosphere in Hospitals

Legal Issues and Alternatives of Mobile Jamming

Cell phone jammers are illegal in most countries — except to military, law enforcement and certain governmental agencies.

It’s a “Property Theft”.

It also represents a “Safety Hazard”.

Legal Issues and Alternatives of Mobile Jamming

In India - legal, Government, Religious Places, Prisons and Educational Institutions use jammers

India has installed jammers in parliament and some prisons.

It has been reported that universities in Italy have adopted the technology to prevent cheating.

Students were taking photos of tests with their camera phones and sending them to classmates.

Alternatives to Mobile Jamming

•While the law clearly prohibits using a device to actively disrupt a cell-phone signal, there are no rules against passive cell-phone blocking. • That means using things like wallpaper or building materials

embedded with metal fragments to prevent cell-phone signals from reaching inside or outside the room. • Some buildings have designs that block radio signals by

accident due to thick concrete walls or a steel skeleton. • Companies are working on devices that control a cell phone

but do not "jam the signal."

Conclusion

• At last we can say GSM, CDMA, 3G Mobile jammer was designed and built it is mainly intended to prevent the usage of mobile phones in places inside its coverage. without interfering with the communication channels outside its range, thus providing a cheap and reliable method for blocking mobile communication in the required restricted areas only.