1

Out lines Introduction

What is sniffer?

Introduction of cellular systems

Working of Sniffer

Advantages and disadvantages of Sniffer.

Introduction

Each and every day thousands of mobiles get misplaced or

lost.

To prevent unauthorized person from making and receiving

the calls we use this technique.

Effective way for the blocking of the lost mobile with the help

of International Mobile Equipment Identifier (IMEI).

The device can be called as a mobile Base station that includes

Sniffer.

What is Sniffer ?

The main scope is to detect the lost mobiles.

For the detection of lost mobile SNIFFER plays a vital

role.

The Sniffer is basically a transceiver that works in the

different frequency that we are commonly used.

The sniffer device has to be designed for easy mobility

for the purpose of detection.

Introduction of Cellular systems

Mobile Station (MS):-The Mobile Station (MS) is made up of two components:

1.Mobile Equipment (ME): Each phone is uniquely identified by

the International Mobile Equipment Identity (IMEI) number. This

number is burned into the phone by the manufacturer.

2.Subscriber Identity Module (SIM): The SIM is a small smart cardthat is inserted into the phone and carries information specific to thesubscriber.

6

Base Transceiver Station (BTS):-

The BTS is the Mobile Station's access point to the network.

It is responsible for carrying out radio communications between the network and the MS.

One BTS usually covers a single 120 degree sector of an area.

Base Station Controller (BSC):-

BSC controls multiple BTSs.

It handles allocation of radio channels, frequency from the MS, and handovers from one BTS to another.

It reduces the number of connections and allows for higher capacity connections to the MSC.

Mobile Switching Center (MSC)

The MSC is the heart of the GSM network.

It handles call routing, call setup, and basic switching functions.

An MSC handles multiple BSCs as well as coordinates with other MSC‘s.

IMEI

International Mobile Equipment Identity.

15 digit unique code that is used to identify the GSM

phone.

When a phone is switched on, this unique IMEI

number is transmitted and checked against a data

base of black listed phones in the network’s EIR .

To know the IMEI number the *#06# has to be pressed.

The sniffer device can be called as a mobile basestation that includes the following importantcomponents:-

1. Sniffer base station.

2. Unidirectional antenna.

3. Tracking software.

DESIGNING FOR THE SNIFFER

The sniffer is a small base station, it includestransceiver section.

It should operate at a frequency that is much differentfrom the frequency of the current cell in which theoperation of detection is being carried out.

SNIFFER BASE STATION

UNIDIRECTIONAL ANTENNA

The directional antenna acts as the eyes for the snifferfor the purpose of the detecting the lost mobile phones.

Antenna is a device which works at specified frequenciesrange for transmitting or receiving the data signal.

In general, antennas transmit power depending on lobepattern which varies from one antenna to the other.

The software is used for the tracking of the lost mobile

phones.

Main feature of this software is to create the data base and this

is mainly done using a Random Access Memory.

The software has the input as the IMEI number of the lost

mobile phone from the RAM.

After getting the input from the lost device that might respond

to the signal sent by the sniffer.

SOFTWARE FOR THE TRACKING

WORKING OF THE SNIFFER DEVICE

o If the connection of the lost mobile is Established with the

BTS, The MSC collects it’s IMEI number.

o If these number are matched with the reported lost no’s .

o It transferred the connection to the sniffer device.

o Searching can perform with the GPS system for more

accurate , fast detection and location can be tracked.

This method is used for finding the lost mobiles effectively.

Cost effective.

Low power consumption.

Easy to design.

ADVANTAGES

In today’s life Mobile phones are the mainly used device for

communication ,so large no. of complaints regarding the

mobile phone that lost are comes.

This method appears to be complex but for large scale

detection the overall effective cost of the design down.

There are certain boundary conditions like the power of

the mobile should be good enough etc.. but this method

can be improved by using modern technologies.

CONCLUSION

Thank you

17