MOBILE JAMMERSTARUNI KANCHARLA – 10/IT/04,

NATIONAL INSTITUTE OF

TECHNOLOGY,DURGAPUR.

CONTENTS

Introduction

Components of mobile jammers

Mobile Jamming Techniques

Design parameters/ specification of mobile jammer

Block diagram of mobile jammer

Applications

Future scope of Jamming Technology

Conclusion

INTRODUCTIONA 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.

Disrupting a cell phone is the same as jamming any other type of radio communication.

COMPONENTS OF MOBILE JAMMERCOMPONENTS OF A MOBILE JAMMER INCLUDE:

Voltage Controlled Oscillator

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 circuit

Tuning circuit can be of two types:

o Open-loop

o Feedback

Open-loop is a saw tooth-wave generator which makes VCO to go from lowest to highest frequency.

The feedback is using PLL to adjust the VCOs frequency constantly.

Noise generator

Noise generator produces random electronic output in a specified frequency range to jam the cell-phone network signal (part of the tuning circuit).

Cell Phone Jammer

RF amplification unit

• RF amplification unit is to increase the area covered by our jammer along with its signal blocking power.

• The more power has our signal blocker, the bigger radius it jams.

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).

MOBILE JAMMING TECHNIQUES• There 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" device

• Type "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" device

• Type "B" devices are also known as INTELLIGENT CELLULAR DISABLERS.

• Unlike jammers, type b devices do 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.

Type "C" device

• Type "C" devices are also known as INTELLIGENT BEACON DISABLERS.

• Unlike jammers, type c devices do not transmit an interfering signal on the control channels.

• The device, when located in a designated quiet area, functions as a beacon and any compatible terminal is instructed to disable its ringer or disable its operation, while with in the coverage area of beacon.

Type "D" device

• Type "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" device

• Type "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/ SPECIFICATIONOF MOBILE JAMMER

• The frequency bands

• Distance to be jammed (D)

Free space loss {F}= path loss (db)= 32.44 + 20 log d(km) + 20log f(mhz)

• Power calculations

BLOCK DIAGRAM OF MOBILE JAMMER

BLOCK DIAGRAM OF MOBILE JAMMER

Power Supply

IF Section

RF Section

APPLICATIONS• There are various types of jamming devices available which are using different jamming techniques.

• 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.

• Church/mosques/cathedral/temple/religious establishment.

FUTURE SCOPE OF JAMMING TECHNOLOGY

• 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.

CONCLUSION

• At last we can say every device is acts as good aspects as well as bad aspects.

• In many place cell phone jammer is useful but at many place it is a problem .

• For this we can take a example that if at any place cell phone jammer is on than anybody wants to use than there creates some problems.

• But its overall performance is very good and helpful in our life.

REFERENCES• "Zone of silence [cell phone jammer]," spectrum, IEEE , vol.42, no.5,

18, may 2005

• www.Howstuffworks.com

• Wikipedia.Org/wiki/mobilephonejammer/

• Mobile personal communications committee of the radio advisory board ofCanada, use of jammer and disabler devices for blocking PCS, cellular relatedservices

• Http://whatisacellphonejammer.com

• Http://blog.Jammer-store.Com/2009/11/how-mobile-jammers-work

THANK YOU