15-05-2013, 12:00 PM
A Seminar Report on SNIFFER
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ABSTRACT
The main scope of this paper 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 International Mobile Equipment Identifier (IMEI) has been done but
however there has been no development or very little progress for the detection of the misplaced
mobile phone. 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 .The device can be called as a mobile Base station that includes Sniffer Base station,
unidirectional antenna, tracking software. The sniffer is a small base station that includes
transceiver section. It should operate at a frequency which is much different from the frequency
of the current cell in which the operation of detection is being carried out. The directional
antenna is an important device that is to be designed and used as it plays a major role.
There are certain boundary conditions that have to be qualified for their 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. Our paper
seems to be a bit costlier for initial setup but the cost is gradually reduced when effectively and
efficiently utilized for the purpose of detection.
INTRODUCTION
One of the most interesting things about cell phone is that it is really a radio an extremely
sophisticated radio, which uses some band of frequency that has the basic working similar to the
ordinary cordless phone. The mobile cellular communication has been appreciated since its birth
in the early 70’s and the advancement in the field of VLSI has helped in designing less power,
smaller size but efficient transceiver for the purpose of communication. But however the
technology has not yet answered the loss or misplacement of the lost mobile phone which is
significantly increasing. In this paper we discuss the problem and the probable solution that
could be done. The IMEI number is a unique number that is embedded in the mobile phone the
main purpose of which is the blocking of calls that is made by unauthorized person once the
mobile is reported as stolen but here we use it effectively for the purpose of detection.
ABOUT IMEI
The GSM MoU’s IMEI (International Mobile Equipment Identity) numbering system is a 15
digit unique code that is used to identify the GSM/DCS/PCS phone. 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 (Equipment ID Register). This EIR determines whether
the phone can log on to the network to make and receive calls. To know the IMEI number the
*#06# has to be pressed, the number will be displayed in the LCD screen; it is unique to a mobile
phone. If the EIR and IMEI number match, the networks can do a number of things. For example
grey list or blacklist a phone: 1. Grey listing will allow the phone to be used, but it can be tracked
to see who has it (via the SIM information). 2. Black listing the phone from being used on any
network where there is an EIR match.
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. Some of the main important things are the frequency that
has to be generated by the transceiver section is around 900MHz range which is a VHF range
and it is necessarily to design the oscillator circuit for that frequency range .Another
important is the cooling that has to be provided to the circuit while designing the circuit that
is to be operated at 900MHz range of frequency. Hence proper design of base station is an
important thing in the design of the sniffer. Mobile phones as well as the base station has low
power transmitter is also transmitting at low power. The transmitter of the sniffer has to be a
low power transmitter. This helps in the process of reducing the interference of the device
with the devices that are in the other cells.
DESIGN OF UNIDIRECTIONAL ANTENNA:
Though the transceiver in a sniffer plays an important role in the detection of the mobile
phone but however it is the directional antenna that has a major role in the design of the
transmitter. The directional antenna acts as the eyes for the sniffer for the purpose of the
detecting the lost mobile phones. Hence the proper design of the directional antenna is
required. 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. The lobe pattern is a two dimensional diagrams
that is used to show radiation pattern. Radiation pattern of directional antenna is shown in
fig1.
SOFTWARE FOR THE TRACKING:
The software part plays a major role in the tracking of the lost mobile phone It is the base
for the antenna to track the lost mobile the main feature of this software is that it helps in
the process of creation of the data base and this is mainly done using a Random Access
Memory. The mobile phone that is lost has certain IMEI number that is embedded in the
chip. This RAM of the sniffer device stores the IMEI number of the lost mobile phone.
Thus this acts as a database or the directory of the lost mobile phone number/The
software that is to be designed in such a way that the software has the input as the IMEI
number of the lost mobile phone from the RAM and this ID done using the SQL query
that fetches the IMEI number.
WORKING OF THE SNIFFER DEVICE
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 by the nearby cells as there may be
possibility of interference by the device with the devices in the nearby cells. The working for the
device is as follows. The fig 2 &3 shows the working of the sniffer; as given in the fig2 it gives
the normal operation of the mobile with the base station and there is a BTS that acts as a middle
man in the process of communication between the mobile and the MTSO which is popularly
known as MSC or Mobile Switching Centre .There is always a two way communication between
devices and before the establishment of the communication the authentication of the SIM card
that has the IMSI or the International Mobile Subscriber Identifier .This IMSI number helps in
the authorization of the user. The second authentication is the authentication of the handset,
which is done in EIR or the Equipment Identifier Register. This register is located at the MSC
and it contains the IMEI number of the lost handset and if the signal is obtained from the normal
one then the two way communication is established. The IMEI of the lost mobile phone number
once has been reported to the service provider, who keeps in track of the record of lost mobile
phones. The MTSO or the MSC which keeps in track of all the mobile phones with IMEI number
and the IMSI number has the information of the lost mobile phones location which means the
location of the cell where the lost device is because of the two way communication with the
device the BTS of the lost device is known to MSC.
CONCLUSION:
Since the boom of the mobile phone for the purpose of the communication there has been a large
no. of complaints regarding the mobile phone that is being lost and there has been no effective
method developed for detecting the lost device. The given paper dealt about the idea of
development “Sniffer for the detection of lost Mobile phones” paves a way by means of which
the lost mobile phones can be recovered. But the process of detection is yet to be developed
through the software and demo has been developed and is with the authors. The demo has been
written in VB that gives the over view of how the lost mobile is being detected and the software
as been written in C. The SQL has to be used for the purpose of querying and the internal
architecture is of lesser complexity compared to the base station as this mainly involves the
control signal and there is no need for the voice process. The design involved the following:
Design of the sniffer base station design of unidirectional l antenna, development of software for
tracking. Though this method appears to be a little bit complex involving the design of the sniffer
but however for large scale detection the overall effective cost of the design and the detection
scales down. There are certain boundary conditions or criteria that have to be qualified for the
identification of the lost mobile like the power of the mobile should be good enough , the mobile
phone should not be in the shadow region etc., but however this method can be improved by
using modern technologies and devices.