This document discusses the design and working of a sniffer device to detect lost mobile phones. It begins with an introduction explaining the need for such a device. It then describes the key components of a sniffer - a sniffer base station, unidirectional antenna, and tracking software. The document explains how the sniffer works by increasing its frequency to detect lost phones based on their unique IMEI number. It highlights advantages like being cost-effective and easy to design. In conclusion, it states that this method can effectively find lost mobiles using modern technologies, given certain qualifying conditions are met.

1. Visvesvaraya Technological University
Jnana Sangama, Belgaum
Seminar On
SNIFFERS
Under the guidance of By,
Department of Information Science and Engineering
Rajiv Gandhi Institute of Technology
Cholanagar, R T Nagar Post, Bangalore-32

2. SNIFFER FOR
DETECTING LOST
MOBILE PHONES
Presented by,

3. CONTENTS
• Introduction
• What sniffer is ?
• IMEI
• Designing for the sniffer
 Sniffer base station
 Unidirectional Antenna
 Software Tracking
• Working of sniffer device
• Advantages
• Conclusion
• References
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4. INTRODUCTION
• The main scope is to detect the lost mobiles.
• Each and every day thousands of mobiles get
misplaced or lost, though effective way for the
blocking of the lost mobile.
• To prevent unauthorized person from making and
receiving the calls has been done by the
manufacturers of the mobile with the help of IMEI
number.
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5. CONT’D….
• For the detection of lost mobile SNIFFER plays a vital role .
• The sniffer device has to be designed precisely and size should
be reduced for easy mobility for the purpose of detection .
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6. What a SNIFFER is?
• The sniffer is basically a transceiver that works in the frequency
which is in the special unused range that is operated by the
service provided or it can designed to operate at a frequency
that is of much different frequency than the one that is being
used.
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7. INTRODUCTION TO IMEI
• Each mobile device has a globally unique IMEI
(International Mobile Equipment Identity)
• IMEI (International Mobile Equipment Identity)
numbering system is a 15 digit unique code that is
used to identify the GSM phone
• To know the IMEI number the *#06# has to be
pressed, the number will be displayed in the LCD
screen
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8. CONT’D….
• When a phone is switched on, this unique IMEI number is
transmitted and checked against a data base of black
listed or grey listed phones in the network’s EIR
• Grey listing will allow the phone to be used, but it can be
tracked to see who has it (via the SIM information).
• Black listing the phone from being used on any network
where there is an EIR match.
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9. DESIGNING FOR THE SNIFFER
• The sniffer device can be called as a mobile base station that
includes the following important components:
 Sniffer base station
 Unidirectional antenna
 Tracking software
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10. SNIFFER BASE STATION
• The sniffer is a small base station, it includes transceiver section.
• It should operate at a frequency that is much different from the
frequency of the current cell in which the operation of detection
is being carried out.
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11. UNIDIRECTIONAL ANTENNA
• The directional antenna acts as the eyes for the sniffer for the
purpose of the detecting the lost mobile phones.
• Antenna is a device which works at specified frequencies range
for transmitting or receiving the data signal.
• In general, antennas transmit power depending on lobe pattern
which varies from one antenna to the other.
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RADIATION
PATTERN

13. SOFTWARE FOR THE TRACKING
• The software is used for the tracking of the lost mobile phone
• The programming is done with C or Java. However the C is most
preferred as it is easily embedded with the chips.
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14. WORKING OF SNIFFERS
• The working of sniffers is of two phases
Before Sniffer increases the frequency
After Sniffer increases the frequency
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15. BEFORE SNIFFER INCREASES THE
FREQUENCY
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16. AFTER SNIFFER INCREASES THE
FREQUENCY
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17. EXPLANATION
• From the above figure we have clearly observed the racing of
the lost mobile.
• We have identified the lost mobile using IMEI.
But,
• The location where it is present can be known by seeing at the
output of the software.
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18. ADVANTAGES
• This method is used for finding the lost mobiles effectively
• Cost effective
• low power consumption
• Easy to design
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19. CONCLUSION
• There are certain boundary conditions that have to be qualified
for the identification of lost mobile like the power of the mobile
should be good enough, the mobile phone should not be in the
shadow region but however this method using modern
technologies and devices.
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20. REFERENCES
• Schiller, “Mobile Communication”, Pearson Education
1 Edition, 7th reprint -2003.
• John D Kraus, “Electromagnetic”, TMH
• Jordan et al, “Electromagnetic waves and radiation
system” , Printice Hall
• www.gsmworld.com
• http://ericsson.com
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